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elctric current

elctric current

by 123iitjee.com Support -
Number of replies: 2

This message was originally posted by Akash Sharma

question

There are ‘n’ no. of batteries connected in series in a closed circuit such that the emf of each battery is denoted by e (i) .Each battery has its own internal resistance r(i).Given that r(i) = ke (i),such that ‘k’ is a constant.we are to find the current in the circuit if no other resistance than that of internal resistance of batteries is present. Also there is no other source of potential difference other than that through batteries.

But my question is not this

Current through the circuit is

 I= S e (i) / S r(i)

 =1/k Ãœ

accordingly a constant current is established in the circuit

But when we find the potential difference across ith battery it comes out to be

V (i)= e (i) - Ir(i)

=e (i) - I/k*k*e (i) \ givenÞ r(i)=ke (i)

=e (i) -e (i)

=0

Now the question is

HOW IS THE CURRENT FLOWING IN THE CIRCUIT IF THE POTENTIAL OF EACH BATTERY IN THE CIRCUIT IS ZERO AS THERE IS NOTHING ELSE CONNECTED IN THE CIRCUIT OTHER THAN GIVEN BATTERIES?

(FOR THIS QUESTION REFER CONCEPTS OF PHYSICS(2)H.C. VERMA PAGE NO 188 QUESTION NO. 8)

DO ANSWER THIS QUESTION

AKASH

In reply to 123iitjee.com Support

Re: electric current

by Manish Verma -

fig.

Let us simplify the situation by considering a single cell directly connnected through an ideal wire.  The current in the circuit \(I=\frac ER\) where E is the emf of the cell and R is the internal resistance.  The potential difference across the terminals of the cell is 0.  However, if you look at the two points inside the cell, you find that the potential difference between these two points is E.   This only means that non-zero potential difference between any two points in a circuit is sufficient to generate current.  It is quite possbile that potential difference is zero between other two points in the circuit but still the current is non-zero.
In reply to Manish Verma

Re: electric current

by Akash Sharma -

respected sir,

thank you for solving my coceptual problem . i'm trying hard to solve problems posted by other users.

akash