## LED Long Leg Polarity- LED Legs – LED Polarity

Welcome to CircuitManiac.com. This is my first article in basic electronics. Stick to my article and you will get the answers for all your question related with LEDs. (LED Long Leg Polarity)

## What is LED Long Leg Polarity?

Here is the image of a LED. Can you see, there are 2 pins in this LED. (2 led legs) Also, One pin of the LED is longer than the other one. That longest pin is used to indicate the positive terminal of the LED which is also used to connect with the positive side of the battery. Also, I think this will be the answer to your major problem. But you are new to work with the LEDs, read the complete article and It will give basic knowledge about LEDs. (LED Long Leg Polarity)

## What is an LED?

Do you know? “LED” stands for “Light Emitting Diode”. That means LED is also a Diode. The diode is a basic circuit component which can allow flowing the current at only one direction. Also, First I will explain how to use a diode in a circuit and after we can go through the LED. Okay, You need to know there is two main components are needed to complete a basic circuit. (LED Long Leg Polarity)

• The first one is the power source, you need the energy to do any kind of work. also that concept valid in the electronic circuit too. So we supply the energy to the circuit with the form of electrical energy using the batteries, AC line, solar cell or something like that.
• The second one is the load, Also, This is some kind of component which can do some work using the electrical energy. Ex: LED, resistor, heating coil, etc…

## What is the Circuit?

Here is the image of the simple circuit with a battery as a power supply and a resistor as a load. Also, normally we consider the current is flowing from the positive terminal to the negative terminal of the battery. Also, What happens when we connect the battery in upside down (opposite side) In this circuit? Let’s see about that…

Okay, now we can see here when the battery placed in the opposite direction and also the current flow is moving in the opposite direction. But when we create a circuit and we need to allow to flow the current flow in only one direction. In that case, the diode is coming to our help. That component (Diode) will keep our circuit current flow at only one direction. Let’s see the diagram for better understand. (LED Long Leg Polarity)

## What is the Diode?

Here are the diagrams, In the first diagram, we have a diode and a battery with connected to the battery positive terminal with the diode positive terminal. In that kind of circuits are called the “diode forward biasing circuits”. In the second diagram, we have the same circuit but the battery connected with the opposite direction. Also, This kind of situation, the diode is not allowed to flow the current through the circuit. Also, this type of circuits is called the “diode reverse biasing circuits”.

## Symbol of the Diode

Now you know about why we use diodes in our circuit?. But we have to know how to represent a diode in a circuit diagram and what kind of information we can get from that symbol. I will explain all the important information you need to know. Okay, here is an image of the real diodes. Watch it and remember this component. Also, This is one of the basic components in the electronics.

This is a different kind of diodes. I hope now you can identify them easily. Okay, our next step is to identify the diode symbol and how to find the polarity from the symbol.

## Symbol (Diode/LED Long Leg Polarity)

Now we all know there is positive and negative terminals are in the diode. When we want to add a diode to the circuit with the forward bias (to allow the current to flow through the circuit), You need to connect the positive side of the diode to positive side of the battery or negative side of the diode to negative side of the battery. To do that, you need to identify the positive and negative terminals in the diode and also the battery. But in the battery, they also marked the positive and negative sides. In the diode, we have to identify the negative terminal with the silver line which is marked on the diode body. But how we can identify the polarity of the terminal using the symbol of the diode?

I create a diagram for you to remember the polarity of the diode and the diode symbol. just refer to this image and understand the method I gave to you. Then you get the polarity of the diode easily.

I hope you can understand the concept that I try to explain. Try to thinks like this. The arrowhead point to the direction that can flow the current through the diode. Another side current will block by the diode. Okay, this is enough about the diodes. Now we move to the LEDs. (LED Long Leg Polarity)

## LEDs (LED Long Leg Polarity)

You already know LED is one type of diode. We can use the LED as a diode. It will allow flowing the current only one direction. As I mentioned earlier, LED has positive and negative terminals. I hope now you can identify these terminals. There is only one different behaviour to different LED from the diode. That is LED can convert the electrical energy to the Light energy. That’s why we call this kind of diode as “Light Emitting Diode”. LED emits the light when the current flowing through it.

## Symbol of the LED

Here you can see all of the polarity information in one image. Save it, It’s important for you. In the symbol, we have the same kind of symbol like a diode and additionally, two arrows pointed out from the symbol. It indicates this diode (LED) can emit the light. Also, LED can emit light only when the current passing through it. As one kind of diode, there are two states in this LED (forward biasing and reverse biasing). So the LED only emit light when it was in forwarding bias. (LED Long Leg Polarity)

Okay, now I hope you have all the basic knowledge about LED. If you have any kind of doubt please comment here. I will reply as soon as possible. Also, don’t forget to give feedback about my article and share with your friends. (LED Long Leg Polarity)

You can find here about 9v battery and led circuit and visit CircuitManiac to get more article like this. Thank you… 🙂

## 9v battery and led circuit-Simple LED Circuit

I know you are new to the electronic field. Also, I guest you burn a few LEDs at this movement (haha). Do you want to know why? Okay then, stick to my article. I will explain how to connect LEDs correctly and also what is the reasons you burn your LEDs. (tags: Simple LED Circuit, 9v battery and led circuit)

First of all, we connect the circuit now, after that you can read what is the theory behind all these things as your interest. All of these theories are explained at the end part of this article. Okay let’s go to the article but I recommend reading the theory part first and after reading these things.

## What do we need?

• LEDs
• any colour of the LED
• Resistors
• 10, 390, 470, 560 ohms
• Battery
• 3v, 6v, 9v, or 12v
• wires
• normal circuit wires

We have two terminals in LED, a longer one for the positive terminal and a shorter one for the negative terminal.

## Simple led circuit: 1.5v battery

Do you have a 1.5 V battery? okay then, find another 1.5 V battery. Because LED needs a minimum of 1.8 V to operate, therefore, you can’t operate a LED using a single 1.5 V battery. (1.5 < 1.8)

## Simple led circuit: 3v battery with 10 ohms resistor

Okay, here is the simple 3 V LED circuit diagram and the Example circuit that I made for you. First, you can find 3 V battery or get two 1.5 V battery and connect them with serial way like the diagram and also use 10 ohms resistor to protect the LED but it was not necessary. always remember that the longest pin in LED is for positive (+) and a shorter one for negative (+). I hope you can understand this and also please read the Theory part of this article which is in the end part of this article for more information.

## Simple led circuit: 6v battery with 390 ohms resistor

Here you can see the circuit diagram and also you can use four 1.5 v batteries or one 6 v battery with this circuit. The 390 ohms resistor is the most important component in this circuit and also if you forget to connect this to the circuit then surely your LED will burn. You have to read the final heading (Theory) of this article to get more knowledge. (tags: Simple LED Circuit)

## 9v battery and LED circuit with 470 ohms resistor

Here are my 9v battery and led circuit with a 470 ohms resistor. Also, You can see positive and (+) and negative (-) terminals are marked in the 9V Battery. Also now you know the positive (+) terminal is the longest pin and negative (-) terminal is the shorter pin in the LED. For more information, continue reading this article and also you can get all the knowledge about these LEDs, Resistors, and Batteries. (tags: Simple LED Circuit, 9v battery and led circuit)

## how to connect led lights to car battery (12 v battery with 560 ohms)

Here you can see, this diagram shows how to connect a LED with a Car Battery (12). You have to use 560 ohms resistor to connect with this circuit and also you can refer more with this article. (Read the theory part of this article which is in the last) (tags: Simple LED Circuit, 9v battery and led circuit)

## THEORY

Hi there, Welcome to the boring part of this article and also Please refer to this part completely I’m sure you will get something from here. Don’t forget to comment on this article and also give your idea and point out the topics that I missed here. 🙂

I hope you have a battery and some LEDs. When you connect your LED to the battery directly it will destroy immediately. Do you know normally LEDs are working in the 1.8 – 3.8 V voltage range? However, the range varies with the color of the LED. (tags: Simple LED Circuit)

The following chart will help you to understand the LEDs operating voltage.

Okay, now take your battery and check it’s the voltage. Also It has been marked on the battery. It should be one of the following values: 1.5V, 3V, 6V, and 12V. (tags: Simple LED Circuit)

## LED with 1.5v battery

Let’s see what happens when you connect the LED directly with the 1.5V battery. Now you know LEDs operating voltage is between 1.8 and 3.8V. but when you supply 1.5V to the LED, which is lower than the minimum operating voltage of the LED. Also If the battery has 1.5V, you cannot get the perfect brightness from it. Then you realize that you can’t emit light from
LED using a 1.5V battery.

## LED with 3v battery

Now let us see what happens when you connect the LED directly with a 3V battery. 3V is a value, which is in the operating voltage range of LED. Now again look at the “table 01” that I mentioned above. According to that, you can see white, blue, green, pink, UV needs a minimum of 3.2V to get maximum brightness. Then you can understand that you cannot operate these color LEDs using a 3V battery. However, according to “table 01” red, yellow and orange LEDs have 2.2V of maximum operating voltage. But 3V > 2.2V. Anyhow, we can see led can emit brighter light without burning when they connect into 3V. But it can shorter their life. Also To avoid this problem we can use resistors. (tags: Simple LED Circuit)

## LED with 6v, 9v, and 12v battery

Finally, let’s see what happen when we connect LED directly with 6V, 9V or 12V battery. I think now you have all the knowledge to imagine this situation. These voltages are higher than the maximum operating voltage (6V/9V/12V > 3.8V). Also, If we connect LED directly with these batteries immediately it will burn. To avoid this you need to use resistors. (tags: Simple LED Circuit)

Resistor???

Now let’s see what is the resistor. The resistor is a very important component in electronics. The resistor is used to block the current through a circuit and then reduce the voltage of the component that we need. Also, Resistors can connect series or parallel with the circuit according to our requirements. When it comes to the LED, resistors are connected series with LEDs. Also, The value of the resistor can be calculated using the color code. (tags: Simple LED Circuit)

## Let’s see about the circuits

You can scroll up and see the relevant circuit diagram that I provided in with the related title.

3V basic LED circuit

Let’s see how we can connect LED with a 3-volt battery. Also If you are using Red, Yellow or Orange color LEDs, you need to connect it through 10 ohms resistor.

6V basic LED circuit

If you are using red, yellow or orange color LEDs, then connect the LED through 210Ω resistor. Also If the LED has a different color (except red, yellow and orange) we use 140Ω resistor series with the LED.

9V basic LED circuit

If you are using red, yellow or orange color LEDs, also you need to use a 360Ω resistor with LED. Or if you use a different color than above use 290Ω resistor to protect your LED.

12V basic LED circuit

If the LED has red, yellow or orange use 510Ω resistor series with the LED and also if LED has different colors use 440Ω resistor. (tags: Simple LED Circuit, 9v battery and led circuit)

Okay, I think you get something from this article. now you can give feedback for my article. Click here to read more article in my site and also you can refer more here. Thank you…

## What is an Arduino?

Arduino is a simple programmable Circuit board, just like a small computer. You can program this to input data, process data and also get output from it or perform some action as output. Arduino is an open hardware development device, therefore you can program and create whatever you want it’s free. and We can make simple color light Patterns to complex Robots using this Arduino.

This is my Arduino nano board, And also you can buy different models of Arduinos. Like Arduino Mega, UNO, nano, pro mini, also, etc. But I recommend using UNO or Nano as a beginner.

## What are the components of this board?

This is the main part of the Arduino board, The Atmel chip. this is nano and also it has Atmel mega 328p chip as the main IC. You can see Different kinds of Atmel chips in different Arduino boards. Let’s see about that.

## Other components

Let’s see about the components in this Arduino nano board. Also, This is the front side of the circuit. You can see here,

1. Oscillator
• This Oscillator generates 16 MHz frequency, Also That frequency helps to operate this Atmel Mega 328P chip. In different Atmel chips need a different value of frequencies. Also, All the values are shown in the table.
2. Reset Button
• This is a simple push-button, also You can press this to restart the program in this board.
3. USB Mini-B Port
• This port is used to connect this Arduino with your PC. also You can refer more to Wikipedia.
4. LRD Indicators
• Here you can see 4 lights, Also It indicates some information to the user. First and also Second lights indicate the serial communication of this Arduino board. Also, The third light indicates the power connection of the board. Forth light for the Testing purpose and also we can use it to get output from this board.

Also, Let’s see back side of the nano board,

1. Serial Communication IC
• Atmel chip only can operate with serial signals, therefore This IC (CH340G) helps Atmel chip to Communicate with the PC. It converts USB data signals to serial data signals.
2. 3.3V Regulator
• This Arduino operates with 5V voltage. Sometimes we need 3.3V to connect some components with this board, In that case, we can get that 3.3V output from this regulator.

## Arduino Nano pin diagram

1. Digital Pins
• We have 12 digital pins in nano. Also, we can use these pins to connect digital components. It can only operate with two-stages, in high stage pin has +5V voltage and also low stage pin has 0V voltage which is equal to the ground pin.
2. Analog Pins
• Here in Nano has 8 analog pins. Also, we can get analog readings through these pins. Also, It can vary between 0V to 5V.
3. Reset Pins
• There are two reset pins we have in nano. Also If we supply this pin to +5V voltage, the board will consider the same action as we press the reset button on the board. Also, It will restart the program in the Arduino.
4. Ground Pins
• Also, This is the 0V pin. We can use this pin when the components are connecting to this board and also we supply external power for this board.
5. 5V Pin
• Also Using this pin we can get +5V dc voltage from this board.
6. 3.3V Pin
• This pin is using the 3.3V regulator, Also we can get +3.3V output from this pin.

## What is the difference between Arduino Nano and UNO?

You can see here, when we compare these two UNO board is larger than Nano. But components in there are same. Also, Thay all are work with the same concept.

Also, I think now you are ready to program this board. You can see how to work with this in our next article. you can read more articles in our phobia.tech site and also you can refer more from here.

## What is Tesla coil?

Tesla coil is a device that can transfer energy through space. It can transfer energy within a small distance. But the distance can be varied with the Tesla coil power. This is a similar theory which is using in the transformers. (tags: how to build a tesla generator)

Tesla coil was invented by Nicola Tesla. There are two coils in the Tesla coil (Primary coil and Secondary coil). When we supply the Low voltage and hi-frequency to the Secondary coil, the Primary coil will generate the hi voltage. Also, that voltage will create a capacitor between the top end and the bottom end of the Primary coil.

## What do we need?

• magnetic Copper wire for Primary coil (recommend to use 28 gauge copper wire).
• But I use a Toy motor to get copper wire. 🙂
• magnetic Copper wire for Secondary coil (recommend to use 22 gauge copper wire).
• But I use a house wiring wire to get copper wire. 🙂
• PVC Pipe
• Recommend to use 2cm Diameter and 9cm Length pipe
• Transistor
• 2N2222A
• Resistor
• 22K Ohm
• Color code: RED, RED, ORANGE, GOLD
• Battery (9V)
• Cardboard
• I used a piece of wood.

(tags: how to build a tesla generator)

## Let’s make a simple stand for the Tesla coil

(Use your own method to make it.)

• I found this piece of wood, but you can also use Cardboard Sheet.
• Also I found this items, inside the lamp holder. I used it to attach wires and coil to the wood plate.
• Also, i brought this jumper wires from eBay.
• Now attach the wires to the plate

(tags: how to build a tesla generator)

## Now we make the secondary coil

Create the coil like this from the wire that we get from the house wiring wire.

## Now we can complete the stand

• Connect the secondary coil to the stand.

(tags: how to build a tesla generator)

## Now we make the primary coil

• Get the magnetic coil, that we got from the toy motor
• And the PVC pipe
• Then winde the coil 300-400 turns to the Pipe.

## Now we attach the primary coil to the stand.

• Glue the Primary coil to the stand, and take the bottom coil end to the other side of the stand through the hale.
• Now get the wire and connect it with bottom end of the coil.
• Before connect the wire, burn the end of the coil.

(tags: how to build a tesla generator)

## Now we can create the Circuit

Now create the circuit using this circuit diagram. In my case, I create a temporary circuit using the Breadboard. this is not necessary, you can use PCB or Vero board directly.

Now make sure the circuit is working.

Okay, now we can go with the Vero board. This is the Vero board that I buy from eBay.

And i cut the piece of the board.

Now connect the components to the vero board and solder it.

## Complete the Tesla coil (How to build a tesla generator)

Connect the Primary and Secondary coils to the circuit.

Now complete the setup. 🙂

## I recommend watching my full youtube full guide video of how to build a tesla generator.

You can refer more in here and other articles from my site phobia.tech.

## Rocket Motion – Variable Mass Problem (Mechanical Physics)

Rocket Motion – Variable Mass Problem (Mechanical Physics Part 2)

• v is upward vertical rocket velocity related to Stationary Earth.
• vo is the initial rocket upward velocity of propellant Fuel relative to stationary earth. also initial exhaust velocity relative to stationary earth.
• D is downward atmospheric force, this is neglect this time for simplicity.
• T – Thrust force applying Newton’s 3rd Law.
• u – exhaust velocity relative to the rocket.
• Fext – Net external force expended in accelerating rocket and also variable mass propellant fuel.

## Defining Ideal Rocket

• There is no twisting or turning moment force acting on the rocket.
• The thrust T acts precisely at the rocket’s center of mass.
• The rocket and it’s propellent fuel mass solely involved in upward translational rectilinear motion.
• There is a realistic assumption of constant fuel burn rate implying constant thrust T.
• The gravity acceleration is assumed to be constant.

In the beginning part of the analysis, the rocket does not escape the earth’s gravity field.

## Generalized Equation (Rocket Motion – Variable Mass Problem)

This generalizes the rocket equation considers rocket weight by factoring out external gravity force of rocket and fuel weight from Fa but keeping drag D as part of Fa .

Rocket Motion – Variable Mass Problem (Mechanical Physics Part 2)

## Rocket Equation 2 (Rocket Motion – Variable Mass Problem)

This equation is really / corollary to the above equation.

• g is constant gravitational field acting upon rocket and propellant masses and also thrust force T.
• m – Total mass including propellant fuel.

[katex]T\quad =\quad \frac { ud(m) }{ dt }[/katex], thrust excreted by exhaust velocity of propellent.

g is constant gravitation field then,

Since it vaeies inversly thrue rocket length.

• vo – Initial rocket velocity.
• vbo – Burn out velocity, rocket velocity moment at complete.
• dv = vbo – vo, maximum burn out velocity.
• u = – ( v – vo ), effective exposed velocity.

Initial total rocket and propellant

## Rocket Equation 3 (Rocket Motion – Variable Mass Problem)

Also, this gives maximum rocket velocity at time t. Rocket Motion – Variable Mass Problem (Mechanical Physics Part 2)

## Rocket Equation 4 (Rocket Motion – Variable Mass Problem)

Propellent mass function,

Which is the fraction of initial mass that is reaction mass.

## Thrust to weight ratio

In other words the specific impulse can be defined as the ratio of the thrust produce to the rate at which the rocket consium its fuel.

## Question: (Rocket Motion – Variable Mass Problem (Mechanical Physics Part 2))

Consider a rocket moving in a space suppose that 2.1×106 kg of fuel a consiume during a burn last in 1.5×102 s. Give that there is a constant force on the rocket of 3.4×107 N. During this burn calculate the velocity of the exposting fuel. Hence calculate the increasing speed resulting some their burn. If the initial mass is 2.8×106 kg.

What is the initial vertical acceleration that can be important to this rocket when it is launched from the earth?

………….

## Rocket Motion – Variable Mass Problem (Mechanical Physics Part 2)

You can refer to “How to Build a Tesla Generator” from HERE, Also refer to the wiki.

## Introduction To Visual Basic Application Development

• “Visual” refers to the method used to create what the user sees (Graphical User interface).
• “Basic” refers to the BASIC (Beginners All-Purpose Symbolic Instruction Code) programming language.
• It is a high-level programming language that evolved from the earlier DOS version called BASIC.
• Visual Basic originally created to make it easier to write programs for the Windows computer operating system.
• One of the major reasons why Visual Basic has been so successful is that it includes everything that is necessary to write programs forWindows.
• For many years, Microsoft Visual Basic has been the world’s most popular programming language.
• From its very beginning, Visual Basic has brought unmatched flexibility and ease of programming to theWindows platform.
• In its previous six versions, Visual Basic evolved into an extremely powerful development tool that was equally at home in business, academia, engineering, or everywhere else in which windows applications were being created.
• The latest version of Visual Basic, called Visual basic .NET, is the most significant evolutionary change yet in the language. (Introduction To Visual Basic)

## General Features Of The Visual Basic

• GUI:- Graphical User Interface is there to represent the program objects and also the techniques.
• Modularization:- Good program practice to modularize program.
• Object-Oriented:- Creating objects while writing programs.
• Debugging:- Runtime debugger helps to find and also fix the bugs/ errors at runtime.
• Data Access aspect:- Users can able to create a database and also retrieve data at runtime.

## Introduction to Visual Studio Express 2012

• Visual Basic Express 2012 is almost similar to Visual Basic Express 2010 & 2008, but it has added many new features.
• Visual Basic Express 2012 no more comes as a stand-alone program, it is now integrating with other Microsoft Programming languages C# and also C++ in a package called visual Studio 2012.

(Introduction To Visual Basic Application Development)

## .NET Framework Architecture

• The .NET Framework is Microsoft’s new platform for the development and implementation of applications program.
• Simply, .NET is a new framework for developing web-based and also windows-based applications within the Microsoft environment.
• Microsoft and other publishers of development tools realized that they could write the code needed to perform a variety of commonly needed tasks and also make this functionality available to the programmer in an easy-to-use form.
• So, the framework did all the work behind the scenes, serving as an interface between the program and the operating system.
• Two main parts of the .NET framework are:
• Common Language Runtime.
• .NET framework classes/ libraries.

## Common Language Runtime (CLR)

CLR is considering as the heart of .NET. It also provides a “runtime environment” for the execution of code written in any .NET Language.

• Features :
• Common type system
• Intermediate Language (IL) to native code compilers
• Code execution and security
• Memory Management
• Garbage Handling
• Exception Handling
• Much of the functionality available to the VB .NET programmer is provided by the .NET Class Framework.
• This is a rich set of classes, interfaces, and also structures that provides support for data storage, access to system services, input/output, security and a whole host of other things that the programmer needs.
• The class framework is arranged hierarchically using the concept of namespaces.
• A namespace is nothing more than an identifier that is used to group related items together.
• The root namespace contains classes for all of the base data types (Integer, Char, Array and so on) as well as for the Object type that is the base for all .NET components.
• Applications that can make use of .net class library:
• Windows applications
• Console applications
• Web applications
• XML web applications/services
• Windows services

## Elements of a Visual Basic Application

From a programming viewpoint, Visual Basic is an object-oriented that consists of two fundamental parts.

## A visual part and a language part

• The visual part of the language consists of a set of objects, while the language part consists of a high-level procedural programming language.
• These two elements of the language are using together to create applications.
• Thus, for our purposes, we can express the elements of a visual basic application as:

(Introduction To Visual Basic Application Development)

## The Visual Element

• From a user’s standpoint, the visual part of an application is provided within a window. This is the graphical interface that allows the user to see the input and also output provided by the application.
• This user interfaces referred to as the graphical user interface (GUI).
• From a programmer’s perspective, the GUI is constructed by placing a set of visual objects on a blank window, or form, when the program is being developed.
• The programmer can place various objects on this form, which is itself a Visual Basic object.
• When an application is run, the form becomes a window that provides the background for the various objects placed on the form by the programmer.
• The standard object Tool-box contains the objects we will use in constructing each graphical user interface.

## Creating a Visual Basic program

• To create a Visual basic program you will need the following three windows:
• Toolbox window for selecting objects
• Form window for placing objects
• The properties window for altering an object’s properties

Additionally, the Solution Explorer window should be visible when you begin.

• Once the design windows are visible, creating a Visual Basic application requires the following three steps:
• Create the graphical user interface
• Set the properties of each object on the interface
• Write the code

## Setting an Object’s Properties

• All objects on a form have properties, which define where on the form the object will appear. The color of the object, its size, and also various other attributes.
• The properties window allows properties to be listed in alphabetic order, by property name or by property category, By default, also the properties are sorted by category.
• The two columns within the properties window are where individual object properties are identified.
• The column on the left is the properties list, which provides the names of the properties of the object also named in the object box.
• The column to the right is the settings list, which provides the current value assigned to the property also on the left.
• The currently selected property is the one that is highlighted.

(Introduction To Visual Basic Application Development)

## Basic Concepts in Introduction To Visual Basic Application Development

The Name Property:

• The names that are allowed for all objects are also used to name other elements in the Visual Basic programming language and are collectively referred to as identifiers. Identifiers can be made up of any combination of letters, digits or underscores( _ ) selected according to the following rules:
1. The first character of an identifier must be a letter.
2. Only letters, digits or underscores may follow the initial letter (Blank spaces, special characters, and also punctuation marks are not allowed)
3. An identifier can be no longer than 1016 characters
4. An identifier cannot be a keyword.

Running an Application:

• At any time during program development, you can run your program using one of the following three methods:
1. Select the Debug Menu and Click Start
2. Press the F5 function key
3. Use the hotkey Alt + D, then press the S key.

Saving a Project:

• Click the File menu and then click Save All.
• At this point, all the forms, code modules, and ancillary files will be saved in a folder. Also, the name of the folder will be the project name.

## OR

• Click ” SaveAll ” icon in the Standard Toolbar.
• Also, It recommends you save your solution to prevent accidental loss of work.

• In a well-designed program, each procedure will consist of a set of instructions necessary to complete and also a well-defined task.
• Although a procedure that is executed when an event occurs is referred to as an event procedure or event handler.
• The following slide illustrated The general structure of an event procedure:

Write two simple event procedures for action while a form loading in the execution of VB .NET

Example 1:

Example 2:

• The first line of a procedure is always and also a header line.
• A header line begins with the optional keyword Private and must contain the keyword Sub (which derives from the word Subprogram), the name of the procedure and also a set of parentheses.
• For event procedures, the name consists of
• an object identification,
• an optional underscore character ( _ ),
• a valid event for the object,
• the parameters in parentheses,
• the keyword Handles followed by the object identification,
• an underscore character &
• a valid event.
• Event procedure templates need not be manually typed because they are automatically provided in the visual Basic Code window.
• Before activating the code window, we need to decide what Visual Basic statements will be included in the body of our event procedure. (Introduction To Visual Basic Application Development)

## Find some additional features of VB .NET compared to VB

For the Visual Application Development (Theory) lesson, click here. also, you can refer more in here.

## Learning Objectives in Visual Application Development

• To provide an introduction to the fundamentals of programming.
• Enable students to build simple and also graphical applications to address the problems they face in academic and business settings.
• Enhance analysis, design, development, troubleshooting, and critical thinking skills.

(Visual Application Development)

## Software Processes

• When we provide a service or create a product we always follow a sequence of steps to accomplish a set of tasks.
• We can think of a series of structured activities as a process.
• Any process that has the following characteristics,
• prescribes all of the major activities.
• uses resources and produces intermediate and final products.
• organized to include sub-processes & activities in a sequence.
• Constrains or control may apply to activities (Budget control and also the availability of resources).
• When the process involves the building of some product we refer to the process as a life cycle. (Visual Application Development)

## Introduction to SDLC

• The Software Development Life Cycle is the process, involving multiple stages also used to convert a management need into an application system, which is custom developed or purchased, or is a combination of both. (Visual Application Development)
• SDLC is . . .
• A model of a detailed plan on how to create, develop, implement and also deliver software.
• A complete plan outlining how the software will be born and also raised and turned over to its eventual user.

## Basic Pattern of General Life Cycle Models

Each phase produces output (deliverables) that will be the input to the next phase. So, a software process model is an abstract representation of a process. (Visual Application Development)

## Sequential Development

• A development strategy wherein a strict set of development phases or stages followed in sequential or linear order.
• Only when one phase or stage is completed can development move on to the succeeding phase or stage.
• Also Sometimes referred to as a classical or traditional method of software development.

(Visual Application Development)

## Iterative Development

• Iterative development is a strategy for scheduling a certain amount of time for rework or revisions in order to improve the quality of the different parts of the system being built.
• Instead, development begins by specifying and implementing just part of the software, which can review in order to identify further requirements.

(Visual Application Development)

## SDLC Models

• Waterfall Model
• Spiral Model
• Rapid Application Development
• V Model
• Agile Model

## Waterfall Model

• Executed the Phases in sequential order
• Completed Each phase before proceeding to the next.
• Customer Can’t see Software until the end of the project.
• It provides a structured approach.

## Advantages of the Waterfall Model

• Relatively simple to understand.
• Give importance to documentation.
• Each phase of development proceeds sequentially.
• Allows managerial control where a schedule with deadlines is set for each stage of development.
• Helps in controlling schedules, budgets, and also documentation.
• It provides a structured approach.
• Generally suited for stable projects.

• Requirements need to be specified before the development proceeds.
• Can’t make the changes in requirements in later phases of the waterfall model. This implies that once the software enters the testing phase, it becomes difficult to incorporate changes at such a late phase.
• No user involvement and working version of the software is available when the software is being developed.
• It does not involve risk management.
• Assumes that requirements are stable and are frozen across the project span.

(Visual Application Development)

## Spiral Model

• The iterative model with an emphasis on risk analysis.
• Aims to combine advantages of top-down and also bottom-up concepts.
• Good for large and also mission-critical projects.
• But success highly depends on risk analysis and can be costly.

## Phases of the Spiral Model

1. : Determine objectives and also constraints.
2. : Assessed the risks and also the activities put in place to reduce the key risks.
3. : Also Chose the development model for the system.
4. : Reviewed the Project and also planned the next phase of the spiral.

• With conventional methods,
• There is a long delay before the customer gets to see any results.
• Development can take so long that the customer’s business has fundamentally changed by the time the system is ready for use.
• It is obvious that there is nothing until 100% of the process is finished.

(Visual Application Development)

“A software development process that allows usable systems to be built in as little as 60-90 days and also often with some compromises”

“A software development methodology that uses minimal planning in favor of rapid prototyping.”

(Visual Application Development)

## Visual Application Development

For the Visual Application Development (practical) lesson, click here. also, you can refer more theory in here.

## What Would Happen To You If You Were Infected With COVID-19?

COVID-19 has infected thousands, and could potentially affect millions of people, all around the world. The coronavirus or COVID-19 originated in wild animals. The reason why it’s been able to spread so easily is that it’s an airborne virus. If someone infected coughs or sneezes near you, then you have a chance of catching the disease. Researchers also suspect that the coronavirus can live on surfaces. So if you happen to touch a contaminated surface, and then touch your mouth, you’re probably going to get infected yourself.

## What happens if you do catch the coronavirus (COVID-19)?

Well, there’s a good chance that you wouldn’t feel anything, at least not immediately. It could take two days or up to two weeks before you notice any symptoms. This means you’d be living life the way you normally would, but you’d unknowingly be infecting everyone around you.

• What would happen if you actually started experiencing these symptoms?

Well, it’d be a bit different for everyone. Your body temperature would first increase as it attempts to fight off the coronavirus (COVID-19). This means you have a fever, causing you to shiver and sweat. These symptoms might last for a couple of days.

## What can you do?

At this point, you should stay home. and stay away from other people. Let’s hope you have some food stocked up. Although being sick sucks, you could use this time to catch up on all your Netflix shows. Maybe even some Phobia.tech articles 🙂 (coronavirus COVID-19)

And when you weren’t doing that, you’d probably be sleeping, as your body would be working as hard as it could, trying to heal. You might think you’re in the clear at this point,

## What if the situation going worse?

But this is when pneumonia could set in. If it did, you’d find it difficult to breathe, and you’d have more mucus in your lungs and nostrils which would lead to more coughing. The shortness of breath and chest pain would continue to get worse. There’s also a chance you’d vomiting. And on top of all this, you’d feel incredibly weak and tired. Your lungs would also continue to worsen. Some patients with the coronavirus have ever experienced. permanent lung damage and scarring. But there’s also much more about the coronavirus (COVID-19) that we don’t know yet. Other organs could be affected, as well. Some patients have shown signs of liver problems. So if you are experiencing any of these signs, you might want to go to the hospital.

## How about in the hospital?

At this point, you’ll be put into a quarantined area so you wouldn’t infect anyone else. Unfortunately, doctors can’t guarantee they can cure you. And a vaccine for the coronavirus might not be available for another year at least. But they’d do their best to help you feel better by giving you painkillers, and lots of fluids. As time went on, your body might be able to naturally heal itself from the coronavirus (COVID-19).

But that’s only if you were a healthy person, to begin with. If you weren’t, then the coronavirus (COVID-19) could cause organ failure and then death. It’s been reported that patients with major health issues like cancer and diabetes have a higher chance of dying from the coronavirus. So if you do happen to catch the coronavirus, it doesn’t mean immediate death, but what you do need to watch out for is infecting other people. This includes the elderly and people with previous health problems. But most people will get sick and survive without any serious damage.

## How could you prevent something like this in the first place?

Wash your hands! It might seem obvious but it works and is the best way to kill the coronavirus (COVID-19). And if you can’t find a sink, then you can use hand sanitizer but it’ll have to have a high alcohol percentage. And also, try your best to be conscious of how you spread your germs, as well as where germs might be. Like, stop touching your face after you get off public transit. Please?

Now, hopefully, you avoid getting the coronavirus (COVID-19), but what would happen if everyone else on Earth caught if? And a global pandemic occurred? Well, we’ll leave that story for another article on phobia.tech or wiki.

## Sony Xperia 5 is fit to pocket and more about Xperia 5

No combat, Sony company had entered the key race of the smartphone market. Their trump is Sony Xperia series. By comparing other companies in the smartphone market, Sony’s statistics are different from others. So, Sony Xperia 5 is also one of the results of their statistics for the targeted niche. Here’s their bit small smartphone which they think, will pit to pocket.

## Let’s unbox

When designing the box, Sony company had not tried to show it is a small phone than their other phones. So, big is too bigger than the phone size. Phone size is 158 X 68 X 8.2 mm. it is only 164 grams in weight. It is 14 g loss of weight and 4mm thinner than Xperia 1. There are 18 W power delivery USB-C charger, USB-C to USB-C cable, USB-C to 3.55 mm adapter and 3.5mm earphones including the phone inside the box.

## Display and design

It is a 6.1 inches OLED display covered with Gorilla Glass 6. This OLED display has a 21:9 Cinema Wide aspect ratio. But they had dropped down the display quality from Sony Xperia 1’s 4K HDR to 1080p quality for Xperia 5. However, by considering the display size of the Xperia 5, 1080p quality will not affect the displays shine. This is Sony’s small version of Xperia. But actually, it is a tiny bit taller than Galaxy S10 Plus.

## Performance and battery

Sony Xperia 5 is powered by Android 9 pie. There is a Qualcomm Snapdragon 855 chipset with 6GB RAM capacity. There is a 128 Gb inbuild internal memory. This memory is common for all nowadays flagship smartphones. However, you can add an external micro SD card up to 1 TB. Sony Xperia 5’s battery is a 3,140 mAh Lithium-ion battery. It is less powerful than the Xperia 1. It available Xperia adaptive charging, stamina, and Ultra stamina mode as well. However, Sony had not added wireless charging facilities. It is a big defect of Sony phones by comparing it with other flagship mobile manufacturers.

## Camera quality

Sony Xperia 5 is also a triple camera phone with 12 MP triple cameras. One camera is with a wide-angle lens, another with a telephoto lens and its third camera is with a Super-wide lens. Its selfie camera is an 8 MP camera. However, the triple camera setup is not magic for flagship mobiles and mid-range mobiles as well. Because some companies like Samsung, Huawei had launched quad-camera setups as well. Besides, they had forgotten AI camera mode, panorama mode, slow-motion video caption, and most of the other creative settings for photos and video recordings. Sony Xperia 5’s night mode is also not in an applicable quality. But it will support to get the best results in selfies and 4K videos with its best strength.

## Price and availability

It priced between US$699 to US$ 799 in leading online stores. It is US$50 to US$ 150 cheaper than Sony Xperia 1. However, this is not a cheap price by comparing other flagship models. This is not the best price for all features packed inside the Sony Xperia 5. However, if you are a Sony lover who seeking a smaller version of Xperia 1, this is yours.

you can get more about Sony Xperia 5 and also you can see more here.

## Sony Xperia 1 Specialties and the review

Sony was not in the race of manufacturing smartphones for a long time. But now they had entered the track against Samsung, Huawei and other companies who were in the race. So, what is the specialty of Sony’s new smartphones to enter the key race? Let’s going to get to know all about Sony’s Xperia 1 and its key features.

## Sony Xperia 1 – Let’s unbox it

The main specialty of Sony Xperia 1 is its size. It is a super slim and super tall smartphone with 167 X 72 X 8.2 mm body size. But it is only 178 g in weight. The display is covered with Gorilla Glass 6. All ports and sub equipment which have to connect to the Smartphone comes with USB type C. They provide, 18W USB-c charger, USB-C to USB-C cable, USB-C to 3.5mm adapter and USB-C headphones inside the box.

## Sony Xperia 1 – Display and design

Sony Xperia 1’s display size is 6.5 inches. It is a large and 4K HDR OLED display. But it is not a fit to frame display. However, it has a 21:9 Cinema Wide aspect ratio. It is good for getting a cinematic experience while watching any video. The display’s brightness is perfect. However, it is not all about you might ask of a phone. There is no notch, no punched hole, or edge to edge display. You can see the traditional look of smartphones with top and bottom lines aside from the display. There are only two colors for the phone as black and purple. You can choose the favorite color from those two colors.

## Sony Xperia 1 – Performance and battery

Sony Xperia is powered by the Android 9 pie version. It is a Qualcomm Snapdragon 855 S0C processor which has 2.8 GHz octa-core, 7 nm processing power. Sony Xperia 1 has a 128GB inbuilt storage with 6GB RAM. This storage and power are well sufficient for best performances. There is a 3,330 mAh Lithium-ion battery. It is a bit small for a flagship mobile. And they not providing wireless charging as well. It is not good news about Sony Xperia 1 as a flagship mobile phone. And its battery life is limited to 12 hours to 14 hours with general usages such as video streaming and web browsing. But there is a fast-charging option for Xperia as, Sony’s Stamina mode.

## camera quality

You can see triple cameras in the top center of the backside of the phone and one selfie camera the top line of the front. All rear cameras are 12 MP cameras. But their task is differing one to another. One camera is with a wide-angle lens, another with a telephoto lens and the rest is with the super-wide lens. The front camera is an 8 MP camera. Video quality is 4K HDR. Beyond this, the camera setup supports supper slow motion, AR effect, panorama, and other creative effects as well. So, the camera setup is similar to other flagship models. But there is no time-laps mode available.

## Price and availability

It had priced between US$849 to US$ 949. Sony Xperia 1 is available in all leading online stores. However, this is not a cheap price for features packed inside the Xperia. However, if you are a totally Sony fan, it doesn’t matter.

you can get more about Sony Xperia 1 and also you can see more here.