I Have Several Question to Ask?

Welcome!

That's quite a range of questions. Some require near-book-length answers. My suggestion would be to google for each one to become acquainted with the subject matter. Also search this site (under "Search all of CR4") for discussions on voltages used worldwide -- there have been several. Same for Power Factor.

A thorough understanding of all those topics will take some time, but it will be time well spent. Good luck .

A1 Profit

A2 Availability

A3 The non-resistive portion of a load. (inductive or capacitive)

A4 Transmission

A5 Electromagnitism

Power Factor is the relationship between active power and apparent Power

W/VA

You described the Reactive component, VARS

You are correct. I erroneously interchanged cause and effect. I hope that I have not created much confusion for zohaibmoazzam.

Typing too fast for the brain is usually my problem.

No big deal.

Have a great day

A1 Profit-OR --For minimizing labour's cost/boredom and for avoiding rejects?

A2 Availability-OR -Because of Standardization already in practice?.

A3 The non-resistive portion of a load. (inductive or capacitive)-OR Of Current?

A4 Transmission OR- Signal currents through wires/Optical Fibre /radio

A5 Electromagnitism OR - Distant Fields travelling through Air(Vaccuum of space) and caused by Exciting the Antenna

Q-3 How can we define power factor? Power factor in an AC circuit is the product of Volts times Amps devided by Watts.

Do that again, please? What is volts x amps? Watts? What's watts divided by watts?

Both posts 3 and 4 are essentially correct. See this article. Interestingly enough, this is one of the quick-to-answer questions in the original post, but even it is not perfectly straightforward, unless the original poster has some background.

Watts divided by watts would be dimensionless, as power factor is. The two "watt" (apparent vs real) values are generally different, so the quotient is not unity.

Watts the answer?

Q1 pollution

Q5 An antenna basically matches the impedance of the transmission line to the air in order to get maximum power transfer. There are many good books on antennas such as the ARRL antenna book. It's a fascinating subject. Have fun!

S

Q-2

The reason that 220 volts is used is to save on the amount of metal in the conductors. Twice the voltage - half the amps = half the size of conductor with the same amount of work (watts).

The US chose 110V with the believe that it was safer than 220V. This goes back to the Edison - Faraday - Westinghouse fights over AC various DC.

And also at that time the US had a surplus of manufacturing that needed to be ultlized.

"Q-1 What is the most important factor regarding Industrial Automation?"

Deciding if Industrial Automation is applicable and/or economical.

"Q-2 In Some countries most of the appliances operates on 110V,but some countries operates same appliances on 220V? what is the reason behind this?"

That is the way the electrical generation-distribution system was set up initially and it is too expensive to change.

"Q-3 How can we define power factor?"

We don't have to define power factor. That has already been done for us by electrical engineering theory.

"Q-4 How a signal travels from any medium?"

That depends on the specific signal and medium.

"Q-5 How Antenna Works?"

That depends on the antenna and frequency,.

You can find more explanations and definitions by searching <wikipedia.org> , <Google.com> , and <Dogpile.com>

You might get better answers here by asking ONE Question at A Time!

Hi zohaibmoazzam,

Welcome to CR4. You have asked some pretty deep questions here and it would be impossible to give a full answer to the them but I think I can give you the basics.

Q-1 What is the most important factor regarding Industrial Automation?

As Ace Boeringa said in his post the primary factor is always profit. As you can imagine there are a myriad of things that could affect the profit and the same is true when you talk of automation. You could and people have, write books on the subject and it is completely impossible to answer it in this situation.

Q-2 In Some countries most of the appliances operates on 110V,but some countries operates same appliances on 220V? what is the reason behind this?

There are numerous voltages used around the world to drive electric equipment but probably the most common voltage is 220 V AC three phase. This link will take you to a list of supply voltages use throughout the world. The bid advantage of using 220/240 V instead of 110 is size of the cabling that is required and the distance it can be transmitted. The power that is lost in a cable is proportional to the square of the current that is flowing through it. If you double the voltage the current required to transfer the power halves and the loss of power in the cable is on one quarter.

The 110 V system has serious limitations when driving items that draw high currents and so there is a secondary split phase system that gives you two separate lines that are each 110 V from ground but give you 220 V between them.

Q-3 How can we define power factor?

Before you can understand what the power factor means you need to understand what AC electricity is and how we measure it. AC or Alternating Current is actually an alternating voltage that swings back and forwards between a positive and negative voltage. Now we do not normally express the voltage as the peak voltage but rather what we refer to as the RMS or Root Mean Square voltage. The RMS voltage is useful because it is the effective voltage. With a sin wave like mains voltages the peak voltage works out to be the RMS voltage multiplied by √2.

The diagram below shows how the voltage (shown in RED) changes with time. Also shown is the current (shown in GREEN) that would be flowing through an ideal inductive load.

As you can see the current is not following the voltage exactly and is delayed by a quarter of a waveform. We call this a lagging current because the current is mimicking the voltage but lagging it real time. Now I am sure you know that the power an item consumes can be calculated by multiplying the current by the voltage. However, in this case we can't use a simple multiplication because the current and voltage are not exactly the same all the time.

We can however calculate the actual power if we know the angle between the voltage and current As you can see the current is mimicking the voltage but it is lagging by a certain time. Since the voltage is a sin wave we can actually express the delay in the current as an angle. This is where the power factor comes in as the power factor can be calculated as;

Power Factor = Cos(Current Lag Angle)

We can now calculate actual power consumption as follows

Power = Power Factor x Voltage_RMS x Current_RMS

The reason we call it the power factor is that it actually gives us the ratio between the actual power that is being consumed to the theoretical power.

I have shown an inductive load in the diagram above and a lagging current but currents can actually lead the voltage as well. You get a leading current when you have a capacitive load.

Power factor is important because it is a measure of how efficiently you are consuming the power and power generators get upset if the angle between the voltage and current gets too far out of phase.

Q-4 How a signal travels from any medium?

I am not exactly sure I know exactly what you mean by any medium but lets for the moment assume you mean a conductor. As you know like electric charges repel each other like, like magnetic poles. First off lets look at what happens with a string of magnets.

Imagine you now have a series of bar magnets all lined up so that the north poles are pointing to north poles and the south poles are pointing at south poles. Each of the magnets is truing to repel the magnets on either side of it. If we now take a magnet at one end and force it closer to its nearest neighbor that nearest magnet will be pushed further away. That magnet will in turn push the next magnet in the line and so on until the last magnet in the line moves.

Ok instead of magnets lets look at a conductor that has electrons that are not fully bonded to the nucleus of the atoms. If I now force an electron in one end of the conductor then it will push on all the electrons in the vicinity. These will in turn push on the electrons further along the conductor and ultimately push an electron out the far end of the cable.

That is how electricity travels along a conductor.

Q-5 How Antenna Works?

To understand how an antenna works you need to understand that an electric field doesn't exist on its own. Wherever there is an electric field there is a magnetic field and wherever there is a magnetic field there is an electric field. In an antenna we force it to generate an electric field. This electric field then induces a magnetic field which in turn produces a further electric field. These two interacting fields are called electromagnetic radiation and they radiate into space in all directions. When they reach a second antenna the magnetic field induces an electric field in the antenna and it is this signal that is amplified and used by the receiver.

And there friends, is your answer.

I admire your ability to roll up your sleeves and type, Masu. There are some who, when faced with so many questions, would do as cannibals might, and throw up their hands.

Thank you soo much, all of the CR4 Crew Suscribers !!!

I learned a lot from here, but i have plenty of questions still to be asked :]]]

so be ready and Prepared ;))

Regards..

Zohaib Moazzam Khan (ZMK)

Do you guys always do peoples homework for them!!!! I mean come on how obvious????

"Do you guys always do peoples homework for them!!!! I mean come on how obvious????"

NO - See post #11. Teach him to fish for himself !