Question

Consider the following four circuits P, Q, R and S which have been set up to find the resultant resistance of two resistors combined in parallel:



The correct way of connecting the ammeter and voltmeter in the circuit is:
(1) P
(2) Q
(3) R
(4) S

Answer 1

For determining the equivalent resistance of two resistors connected in parallel, the ammeter is connected in series and the voltmeter is connected in parallel to the combination of resistors. As the current flows from high voltage to low voltage, so the polarities of ammeter and voltmeter are also set according to the flow of current in the circuit.

Out of all given circuits, only circuit B is correct, as it has both ammeter and voltmeter connected at the right place and with the right polarities.
Hence, the correct answer is option 2.