If the length of the wire be (i) doubled and (ii) halved, what will be effect on the position of zero deflection in a potentiometer ? Explian

Rohan, a Science student purchased a few cells from a shop keeper for his torch. He noticed that the torch was not working will with these new cells. He thought of checking the emf of each cell. Using a potentiometer he measured their emfs and noticed that the emf of each cell was less than the value of oblige him. He then lodged a complaint with consumer forum and got theredressal. Read the above passage and answer the following question: (i) What are the basic values displayed by Rohan? (ii) Why rohan used potentiometer instead of voltmeter to measure emf of the cells? (iii) If the lenght of potentiometer wire is (a) doubled and (b) halved, what will be the effect on the position of zero deflection in a potentiometer.

If the emf of the driving cell be decreased, what will be effect on the position of zero deflection in a potentiometer ? Explain .

If the current flowing in the wire of the potentiometer be decreased, what will be effect on the position of zero deflection in potentiometer ? Explain.

If the e.m.f. of a driving cell be decreased. What will be effect on the positions of zero deflection in a potentionmeter? Explain.

If the length of a wire is doubled and cross-sectional area is halved, what happens to the resistance?

If the length of a wire is doubled by taking more of wire, what happens to its resistance?

What will be the effect on the position of zero deflection if only the current flowing through the potentiometer wire is Explain:- increased

What will be the effect on the position of zero deflection if only the current flowing through the potentiometer wire is:- decreased.

If the length of the potentiometer wire is doubled, the sensitivity for obtaining null point will –