Categories

## What Does The Atomic Number Represent?

In this article, we will be looking at what an atomic number represent. But before we do that, we need to know what an atomic number is in the first place. Right? So we will start from there.

## What Is An Atomic Number?

To answer this, we first need to know what an atom is. But luckily, we have already answered it. So if you go through my earlier article on what an atom is, you will see that it is made up of 3 things. They are:

• Protons
• Neutrons &
• Electrons

Right? So then what is an atomic number?

Well, atomic number is the total number of Protons present in an atom. So as we know, protons are positively charged particles that are present in the nucleus of an atom. So if we count these protons, we will get the atomic number of that atom. It is as simple as that!

Sounds good? Great! But then what does an atomic number represent? Let us answer this in our next section.

## What Does An Atomic Number Represent?

So if an atomic number is the total number of protons in an atom, how is it useful for us? What does it represent?

Well the thing is, an atomic number gives an atom it’s identity!

You see, all the elements in our universe are made up of atoms. And all these atoms have the same 3 things we listed earlier – Protons, Neutrons and Electrons.

So if that is the case, you may be wondering – How doe these elements differ then? In other words, if an electron in an element like Carbon is same as an electron in Oxygen, how is Carbon different from Oxygen? Why do we have these as two separate elements?

Can you take a guess? I want you to take a couple of minutes to think about this, before you look for the answer that I am writing next.

If you answered that it is because of the number of protons in it, then you are right! It is indeed the number of protons present in an atom that decides what type of element it is going to be!

So as an example, an atom with 3 protons in it will become lithium element. On the other hand, an atom with 4 protons will become beryllium.

So as you can see, as the number of protons change, the element’s identity also changes. Right?

That is why we told you earlier that an atomic number of an atom represents it’s identity!

It all now makes sense. Right?

## Conclusion

So there you have it! An atomic number represents the identity of an atom. That is all there is to it. But if you have any questions around it, do let me know in the comments below. Because I will be more than happy to help! Alright?

So with this, I will end this article. See you until next time guys! ðŸ™‚

Categories

## Shift Register Modes, Use, Advantages & Disadvantages

So in this article, we will look at a piece of hardware called the shift register and their modes of operation. But we wont stop there. Because we will also look at their use case, advantages & disadvantages.

So if you are new to computer hardware or learning about what goes inside a microprocessor, then brace yourself. As this is going to be an eye opener for you on how computer works!

So are you ready? Great! Then let us go!

To start with, let us ask ourselves the basic question – What is a shift register? Because only when we know what it is, does it make sense to learn about shift register modes of operation. Right? Let us answer that first!

## What Is A Shift Register?

A shift register is a piece of circuit that you will find inside a microprocessor. It is used to store and modify data. Now this is one of the simplest explanation I can give for a 2nd grade student.

But if you are some one who is studying about computers, this is just not sufficient. So I will have to explain it in a bit more detail. Alright? I will be getting a bit technical here. But it is how you will get a solid understanding of shift register. So you will have to bare it. Okay?

### Technical Explanation

Technically, a shift register is made up of a bunch of Flip Flops. So as you know, a flip flop is a circuit that can store information. It can store data that is in one of the two states – 0 or 1. Right? So what happens when you connect a bunch of these flip flops together? You get a “register“.

So a register is a circuit made up of a bunch of flip flops that can store data having values in 0s or 1s. Now, if that is the definition of a register, then what is a shift register?

A shift register is a type of register where data is shifted from one flip flop to another within the register. But this shift of data does not happen by itself. Instead, it needs a clock signal to do so. So for every input clock cycle, the data get shifted from one flip flop to another. Hence the name “Shift Registers”. Aha! That name now makes so much sense. Right?

The above pic shows how it works. So as you can see here, for every clock cycle, a new input bit enters Bit0. But at the same time, existing Bit0 value shifts to Bit1, Bit1 to Bit2 and so on. But what happens to current value of Bit7? The register will just throw it out! Removed forever!

Now there is one thing for you to notice in the above pic. It is that the bit value here is shifting left. Right? Because of this, we call it a “Left Shift Register“.

But does that mean we also have a “Right Shift Register”? You bet! We do have a right shift register where input is fed to Bit7 & Bit0 will thrown out for every clock cycle!

## Where Do We Use A Shift Register?

So now that we know how a Shift register works, let us see where we can use it.

### Using Shift Register For Multiplication

When you shift bits in a byte to the left, the value of the byte is multiplied by 2! So we can use a left shift register whenever we want to multiply a byte by 2.

### Using Shift Register For Division

When you shift a byte to the right, you are dividing it’s value by 2. So we can use a right shift register whenever we want to divide a byte by 2!

So with that, let us now look at the different modes of operation of a shift register.

## Shift Register Modes Of Operation

A shift register will work in one these four modes:

• Serial In Serial Out (SISO) Mode
• Serial In Parallel Out (SIPO) Mode
• Parallel In Serial Out (PISO) Mode
• Parallel In Parallel Out (PIPO) Mode

So let us take a look at each of these modes one by one. Alright? Here we go!

### Serial In Serial Out (SISO) Mode

In this mode of operation, the data is fed into the shift register serially for every clock cycle. That is, for every clock cycle, the data is shifted either to the right or left serially. The output is also taken out one bit at a time. So both inputs and outputs are serial here. Hence the name SISO. So then how does the Flip Flop connection look like? Take a look at it below:

### Serial In Parallel Out (SIPO) Mode

When we use the shift register in SIPO mode, we feed the input data serially but take the output data out in parallel. But again, this happens at every clock cycle. So how does that look like? Take a look at it yourself!

So as you can see here, we are still feeding the input data serially. But the output is no more serial. We are taking all the output bits at the same time, in parallel. So what this means is that we will get full 4 bit output every clock cycle!

### Parallel In Serial Out (PISO) Mode

In the case of shift register in PISO mode, we feed the input data in parallel but take the output data serially. So what this means is that we will be feeding multiple data bits as inputs for every clock cycle. But will be taking only one output bit for each clock cycle.

So then what will happen to the output of each flip flop? Well, even that will be fed as an input! So, we will be feeding two inputs after multiplexing them together. So how does that connection look like? Take a look at it below:

### Parallel In Parallel Out (PIPO) Mode

And finally, we have the shift register working in PISO mode. So can you guess what in this mode? Yes. In this mode of operation, you have both input and output data running in parallel. So how does that work? Take a look at it first!

So as you can see above, there is a major change in the way we connect the flip flops. In that, you do not see them connected to each other at all. So each input bit goes to a flip flop and it’s output is directly taken out. The only connection that is common to all these flip flops are the clock and clear signal!

So there you have it. Those are the different modes in which we can design a shift register to work. In the next section let us take a look at different types of shift registers that we can use.

## Types Of Shift Registers

Based on the way the data is shifted, we have 5 different types of shift registers. They are:

• Left Shift Registers
• Right Shift Registers
• Bidirectional Shift Registers
• Circular Shift Registers &
• Linear Feedback Shift Registers

Now let explain what each of these registers work like:

### Left Shift Registers

We have already talked about the left shift register. So I think you are familiar with it by now. If not, let me re-iterate. So in the case of a left shift register, the data is shifted to the left on each clock cycle.

### Right Shift Registers

This is just like the left shift register. But here it is shifting the data to the right on each clock cycle.

### Bidirectional Shift Registers

In the case of a bidirectional shift register, we can shift the data in both the directions. So you can shift the data either to it’s left or right!

### Circular Shift Registers

In the case of a circular shift register, the last output is connected back as input. So your data will not be thrown out. Instead, will be shifted either left or right in a circular fashion!

### Linear Feedback Shift Registers

In this type of shift register, the input of one flip flop will be linear output value of the previous flip flop.

## Advantages & Disadvantages Of A Shift Register

It is now time to talk about the advantages & disadvantages of using a shift register. So what are they?

### Advantages Of A Shift Register

• They are very fast to use.
• Very quick when you want to convert data from serial to parallel or vice versa. They are faster than normal serial to parallel converter circuits.
• They are very simple in design. So you can easily rig up a circuit to create a shift register.
• We can use them to encrypt or decrypt the data.
• We can use them to a delay signal.
• It is used in CDMA to generate Pseudo Noise Sequence Number.
• We can use them to track our data!

### Disadvantages Of A Shift Register

While we could see that it has major advantages, shift register has one major disadvantage. That is:

• The strength of the output current coming from a shift register is not so strong!

So there you have it. Those where some of the advantages & disadvantages of using a shift register.

And with that, I will end this article now. But if you have any doubts, do let me know. Because I will be more than happy to answer them! Alright? So see you and take care until next time! ðŸ™‚

Categories

## Difference Between Screen Tearing & Ghosting

In this article, we will learn the difference between screen tearing and ghosting. But I think before we do that, we should look at what each of these terms even means. Why it happens and how we can fix it. Because knowing what is happening at the fundamental level is how we can really fix things. Right? So in short, we are applying the first principle method here!

So are you ready to learn all there is to know about screen tearing and ghosting? Great! Then let’s get started!

## Screen Tearing & Ghosting

### What is Ghosting?

So let us start with Ghosting. What is it? Ghosting is a phenomenon in display screens. It happens when a part of the screen is not updated in time, or the color of the part is not consistent with the rest of the screen.

Because of this, a fast-moving object will leave a trail of its previous position on the display. So in other words, you can say that it happens when a single image is displayed for a long time. Sounds good?

### Why Ghosting occurs?

But why does ghosting even happen? Well, there are many reasons for ghosting, such as the refresh rate of the screen is too low, the quality of the screen is bad, the angle of the screen is too large, the color of the screen is not consistent with the color of the back light.

So in general, it happens whenever a device is unable to render a fast-moving image properly.

But the most common cause of Ghosting is due to the wrong choice of display parameters, such as the refresh rate is too high, or the response time is too long.

### How to fix ghosting?

So how can we fix it? To answer that, we need to first know this – Display ghosting is caused by the human eye’s persistence of vision, and the longer the display time, the more likely the ghosting will occur.

So in other words, if we look at something for a long time, we tend to retain its shape and size in our eyes as an imprint. So the easy way out of this is to change the things we see at a rapid pace!

The ghosting can be reduced by increasing the refresh rate of the display, or by reducing the brightness of the screen.

## What Is A Screen Refresh Rate?

Wait, we talked about screen refresh rate in the previous paragraph. But what does that even mean?

The screen refresh rate is the number of times in one second that a display screen can completely redraw the image. The screen refresh rate is measured in Hertz (Hz). So higher the screen refresh rate, the more smoothly animations and movements appear. And as we read earlier, this also means we will not see ghosting anymore!

That kind of makes sense then right? But then comes my next question.

### What should be the minimum screen refresh rate for smooth output?

So I went around looking for a decent value at which I should set my screen’s refresh rate. And guess what? The recommended screen refresh rate for smooth output is 60Hz. So this begs the next question for me.

### What is the screen refresh rate of an LED TV?

The refresh rate of an LED TV is usually 120Hz. So this is what I found after looking at many latest LED TV specifications!

### Is screen refresh rate of 120Hz good?

So then which refresh rate is really good for me? Should I set it at 60 Hz or 120Hz? Any guess?

Now if you said 120Hz, then you are right! But why? Read on to know the reason behind it!

At 120Hz, The frames are drawn at 120 frames per second. This is a huge improvement from 60Hz where only 60 frames are drawn per second. So a screen refresh rate of 120Hz is really good, as it can make the screen look very smooth and it is not easy to see the screen is flickering.

Okay then! 120Hz it is!

But here is the thing. As I continued to browse around the topic of refresh rate, I came across this other phenomenon called screen tearing! What even is this now?!

## What is screen tearing?

As I looked around to find what it is, I learnt this:

Screen tearing is a graphical artifact in video games and computer graphics. It occurs when the frame rate of a video display does not match the rate of display updates from the computer graphics card.

Alright, very well! So now I have two things to worry about when displaying things on a screen. And here comes my next question – ladies and gentlemen!

## What is the difference between screen tearing & ghosting?

Screen tearing is a phenomenon that occurs when the monitor is not in sync with the graphics card. Hmm…so it is not a problem with the display, but a problem with the way the graphics card is outputting the image.

But on the other hand, ghosting is a problem with the display itself. So they are indeed two different problems. But of course, the difference is very subtle from an end user’s point of view! Right?

## How to fix screen tearing & ghosting?

So the bottom line is, both screen tearing and ghosting happens due to bad refresh rate of the display. But this refresh rate goes bad at both the display frame buffer side as well as the GPU side. So by fixing this refresh rate, things must get back to normal!

Aha! What an elegant solution to each of these problems!

## But where do we see ghosting & screen sharing?

Well the answer is, pretty much on every mobile phone! Be it a gaming smartphone like Asus ROG Phone 3 or your granny’s old feature phone. This is a problem that can happen on any device with a screen and capable of drawing graphics on it!

Categories

## A 600-W TV Receiver Is Turned On For 4 h With Nobody Watching It

A 600-W TV receiver is turned on for 4 h with
nobody watching it. If electricity costs 10 cents/kWh,
how much money is wasted?

So this is a problem that we have taken from the book Fundamentals Of Electrical Circuits By Alexander. But if you want to take a look at the problem yourself, then go to Chapter 1 question 1.39 of the book.

Since this is a problem we have taken from the Chapter 1 – Basic Concepts, it should be easy. But is that right? Well, let us see as we try to solve it, shall we?

So how do we go about solving this problem?

Well as we always do, we will first break the problem into small parts. By doing that, we will be in a better position to understand the problem in the first place. Right?

So, here is our breakdown of the problem.

## The Problem Breakdown

So let us read out the problem once again, line by line. Alright?

Now the first line of the question reads – “A 600-W TV receiver is turned on for 4 h with nobody watching it.

So what do we learn from that? It means that we have a TV which consumes electricity at 600 Watts Per Hour or 600 Watt/Hr. But we can also write this as 0.6 Kilo Watts Per Hour or 0.6KW/Hr, right? So that means:

P = 0.6 KW/Hour

Ok! So with that being clear, we will move on to our next part of the question which reads – “If electricity costs 10 cents/kWh, how much money is wasted?”

From this sentence, we now know that the cost of 1 KW of Power consumption for every hour is 10 cents.

Electricity Price = 10c/KW

So the question after that then becomes quite simple, isn’t it? It is just asking us to find out what will be the electricity bill for running that A 600-W TV receiver for 4 hours.

## A 600-W TV receiver Electricity Cost In 4 Hours?

So solving this now becomes a simple equation:

Total Bill = Power Consumed By TV in 4 hours * Elec. Price

So then what is the total Power consumed by the TV in 4 hours? It is simple right? If the TV consumes 0.6KW in 1 hour, then the amount of Power it consumes in 4 hours is:

Power consumed in 4 hours = 0.6KW * 4 = 2.4KW

So it is now clear right? The TV has consumed 2.4KW in 4 hours. So then what will be the electricity price for this much of power?

Total Bill = 2.4KW * 10 cents => \$0.24