Elementary Electricity

[snoopy]

Hello Snoopy!

 

Sorry, but I am unable to understand you.:evil: Moreover, I haven't read about sine waves and phases yet. Can you tell in another way?

And Turtle's reply also went above my mind. I will try to understand it one more time.

Peace:)

 

You were asking a question on potential difference in which you stated that in India there are 3 different wires live , neutral and earth.

 

potential difference is voltage which is a potential energy.

 

In India you will find there is 220v difference between live and neutral but also you will find that between live and earth there is also a 220v difference.

 

In the UK the voltage is 230-240v ac and can be three phase as well which means there are three live conductors all out of phase with each other.

 

Because they are out of phase there is a difference in potential between them and current is allowed to flow.

 

I hope that is clearer but 3 phase systems are for advanced students and it would be helpful if you could tell me what stage you are at.

 

Peace

[snoopy]

Would an iron particle also do the same? Moreover, do you mean to say that charged particle would go for for infinite disatnce in the direction inicated by the direction of line at the centre of circular loop?

 

No due to iron losses it would quickly become unstable otherwise you would have a perpetual motion device.

 

Peace

[Turtle]

FWTAW

 

DC Circuit Water Analogy >>

Water circuit analogy to electric circuit

 

Mental Models - Google Book Search

[Mohit Pandey]

Well, cardio plumbing is yet again moving the analogy even further from electricity. But I'm not a doctor, I'm a plumber. Here's some interesting reading on rough pipe: >> Transport Phenomena: A Unified Aprroach - Google Book Search

AND

Water circuit analogy to electric circuit

Turtle says that water pressure decreases when there is reduction of cross-section area. Then in the second instance, it is opposite to above.

Which is correct?

[Mohit Pandey]

There is exactly one position where it would go to infinite, but it is an instable position, just like trying to make stay a pen in equilibrium on the sharp side. So theoretically it can happen and practically it never does.

 

Oh!difference between theory and practical!:eek2:

Snoopy- No due to iron losses it would quickly become unstable otherwise you would have a perpetual motion device.

How will be there iron losses? It would lie exactly at the centre of the current carrying loop, wouldn't it?

[Turtle]

AND

Water circuit analogy to electric circuit

Turtle says that water pressure decreases when there is reduction of cross-section area. Then in the second instance, it is opposite to above.

Which is correct?

 

Follow the article(s) I posted links for; they descripe the electricity/water analogy much better than I. What I said is, that the pressure drops the rougher the pipe interior, and I meant to imply all else being equal. Part of that all-else-being-equal is the cross section.

 

A reason I don't like the cardio analogy is that the piping is so elastic. :eek2:

[snoopy]

Oh!difference between theory and practical!:phones:

 

How will be there iron losses? It would lie exactly at the centre of the current carrying loop, wouldn't it?

 

There is always iron losses in a magnet or electromagnet that you can construct this is basically because fluctuating eddy currents in the magnetic field and hysterisis produce a type of heat loss called iron losses some energy can also be lost to sound energy producing a type of hum from the machine.

 

link

Magnetic core - Wikipedia, the free encyclopedia

 

so your iron particle may go round a few times but would quickly become unstable.

[Mohit Pandey]

By all means ask for any specific clarifications. Worth noting is that my descriptions of the water in the pipe analogy all refer to DC current save for my aside on simulating AC in post #16. :phones::

 

I thought I was specific as just before writing in your regard I was telling about my question regarding domestic circuit. Thus, I was pointing to your reply to my domestic circuit question.:doh:

I hope that is clearer but 3 phase systems are for advanced students and it would be helpful if you could tell me what stage you are at.

I had introduced myself in the very first sentence of this thread .I had just been introduced to the world of electromagnetic topics such as magnetic field, magnetic filed lines, solenoid, electromagnetic induction, Fleming's Right hand and Left hand rule. Do you wish to tell me more about this domestic circuit?:(

[Turtle]

I thought I was specific as just before writing in your regard I was telling about my question regarding domestic circuit. Thus, I was pointing to your reply to my domestic circuit question.:)

 

OK. You asked:

In Indian domestic electric circuit, there are three types of wires- earth, live and nuetral.

In India, the potential difference between the nuetral and live wire is 220 V. However, P.D is needed for the current to flow in an electric circuit. And here, isn't the wires different and therefore, shouldn't the P.D be between the beginning and the end of ciruit?

 

I replied:

The neutral & ground circuits are essentially the same. The neutral circuit is the term for ground leads at the generator and along the transmission lines; typically the white wire in buildings in US. The ground circuit in a particular structure has an on-site connection to ground,...

 

So to try & clarify, there is a PD of 220v between live and neutral; a PD of 220v between live and ground; no PD between neutral & ground. You can confirm this with an AC voltmeter at any properly wired outlet.

 

Both neutal and ground leads complete the circuit to ground. The technical difference is the 'neuteal' lead is connected to the Earth along the transmission components, wheras the 'ground' lead is connected to the Earth at the point of service. :lightning:

 

Here's an article in more detal: >>

Ground and neutral - Wikipedia, the free encyclopedia

[Mohit Pandey]

Now, it's clear.:lightning

Happy new year to all!!!!!!!!!!

[Mohit Pandey]

I was asked to find error in the attached picture. But I couldn't. Then I found that the written answer was that the terminals of ammeter are wrongly connected.

How can it be? If the ammeter is placed at the other end of battery , then how its terminals can change. I think there is nothing wrong with the circuit.

 

Am I correct?:hihi:

[Turtle]

I was asked to find error in the attached picture. But I couldn't. Then I found that the written answer was that the terminals of ammeter are wrongly connected.

How can it be? If the ammeter is placed at the other end of battery , then how its terminals can change. I think there is nothing wrong with the circuit.

 

Am I correct?:)

 

You don't need to move the Ammeter to the other side of the battery, just reverse its terminals so the positive side of the battery goes into the negative terminal of the ammeter.

 

You can check the correctness with a battery, a lightbulb, and an Ammeter. If the incorrect connection is made, the needle will deflect in a direction below 0 on the scale, i.e., backwards. I have attached your drawing and one with the 'correction' in red.

 

I used a battery, an LED, and my ammeter and found if I connect the circuit as you gave it, the needle deflects in the correct direction; I think nothing is wrong with the ammeter in the circuit too. :eek::evil:

[Mohit Pandey]

You don't need to move the Ammeter to the other side of the battery, just reverse its terminals so the positive side of the battery goes into the negative terminal of the ammeter.

But why do we need to change the terminals of ammeter, if the circuit is correct?

...............:)

[Turtle]

But why do we need to change the terminals of ammeter, if the circuit is correct?

...............:)

 

:doh: I should have reviewed my electrical circuit symbology. The diagram is wrong because the little bar on the battery symbol is the Negative terminal. Oooooppps! :cup: :)

 

 

 

Circuit Symbols of Electronic Components

[Mohit Pandey]

Sorry, turtle.

But still I am not getting the point. Ammeter is connected in series with battery, isn't it? Also cells are connected in series with one's positive end connected with the other's negative end. So, Ammeter should be connected in similar way. After the negative end of battery , positive end of Ammeter should be connected.

 

Further, if one connects it on the other side of battery ,that is, on left side, then will there be any change in its terminals ? If so, why?

 

I think an elaborate explanation is needed such that a high school student can understand.:shrug:

[modest]

You want the positive end of the ammeter (and voltmeter) to go toward the positive side of the battery. In practice, the red lead will go toward the positive side of the battery. The circuit above therefore needs the ammeter turned around with negative pointing left (like turtle's pic).

 

If you put the ammeter on the other side of the battery (on the top of the pic) the negative should still point left and the positive still point right. When you can follow the positive side of the ammeter to the positive side of the battery then it's correct (regardless of what side of the battery it's on).

• the battery depicted has positive left and negative right
  
• the voltmeter is correctly orientated (+/-)
  
• the voltmeter is correctly situated in parallel
  
• the zig-zag line is a resistor
  
• the ammeter is correctly situated in series
  
• the ammeter is backwards
  

 

Take a look at week 5 on this website:

ENT 171

 

-modest

[Mohit Pandey]

Modest ! I think I am in confusion as usual. So, please be patient.:)

 

You want the positive end of the ammeter (and voltmeter) to go toward the positive side of the battery.

 

Sorry, this is not entirely what I want. First, I ask you if there is any problem with my attached picture of a circuit. Then , if there is any problem, then why we need to change the terminals of ammeter.

I told you about my understanding of a series connection and what shall be the result when a device is connected in series with it. I showed it with an example of cells connected in series. See it again in my previous post, if you haven't read it yet.

 

Now what shall be the result if we connect ammeter on the other side of battery,i.e to the positve side. It shall look like below. The "A" is ammeter |~|~ is battery. Positive end of both appliances come first.

 

+A-___________________+|~|~-______

 

In practice, the red lead will go toward the positive side of the battery. The circuit above therefore needs the ammeter turned around with negative pointing left (like turtle's pic).

I couldn't understand the term -red lead .

 

When you can follow the positive side of the ammeter to the positive side of the battery then it's correct (regardless of what side of the battery it's on).

[*]the ammeter is backwards

I couldn't understand this also. Moreover, the ENT website has no circuit diagrams but rather actual images of circuit with which I am not familiar.