In the above circuit, connect a nichrome wire of length ' between points X and Y and note the ammeter reading.

(i) When this experiment is repeated by inserting another nichrome wire of the same thickness but twice the length (2L), what changes are observed in the ammeter reading ?
(ii) State the changes that are observed in the ammeter reading if we double the area of cross-section without changing the length in the above experiment. Justify your answer in both the cases.

Explanation

(i) The ammeter reading will decrease (becomes half). This is because with the increase in length, resistance of the circuit increases, hence current decreases, .
(ii) The ammeter reading will increase (becomes two times). This Is because as area increases, resistance decreases and hence current increases.