Question

Basic doubt in the working principle of potentiometer.
When the potential difference between points A and C in the given diagram equals the EMF of the cell epsilon . Why doesn't current flow through the branch that contains epsilon.

Answer 1

@experimentX @TuringTest some help needed.

Answer 2

@UnkleRhaukus @Callisto some help needed.

Answer 3

what is the difference between displacement current and current?

Answer 4

displacement current is defined as the current produced due to changing magnetic field....and current is just movement of charged particle under the applied potential difference

Answer 5

@sagarsen123 please ask your question in a new thread.

Answer 6

basically potentiometer works on the fundamental principle of potential drop across the resistor ....now a wire or a conductor of length 'l' is also acts like a resistor wherein potential drop is measured by moving jockey ..as we know that \[v=i*r and v= (i* p*l)/A \] therefore V is proportional to length . and whilst solving potentiometer we consider V directly proportional to length of wire

Answer 7

now current will not flow through the branch containing epsilon because at the two terminals of epsilon potential drops are equal ...and the necessary condition to flow current is potential difference...

Answer 8

@ghazi Yes and the branch has a potential difference of epsilon right?

Answer 9

right....the potential drop across the length of wire that is A and C is equal to epsilon therefore n current flows in it

Answer 10

Yea thank you.

Answer 11

anytime

Answer 12

huh ... what's that set up ...? measuring internal resistance?

Answer 13

no i guess it's measurement of value of epsilon..by finding out null point that is V1/V2= L1/L2

Answer 14

Yes it is for measuring epsilon.

Answer 15

what is epsilon?

Answer 16

The electromotive force of the cell.

Answer 17

unknown potential..or you can say any external battery whose potential is to be measured

Answer 18

There must be a current I2 through E right? but all the books claim that I2 is 0.

Answer 19

see for I2 to flow through it the two terminal should be at different potential but the ends of E and the wires have equal potential that is potential drop across the wire is equal to E so how come a current can flow in a loop when there is no potential difference