7 The diagram shows three appropriate meters, P, Q and R, connected in the conventional way in a circuit. The switch is initially open. The switch is now closed. What happens to the readings on each meter?

Answer:

7) H

With the switch open, the circuit was in series. With the switch closed, the circuit became parallel.

Parallel circuits have a lower overall resistance than a series circuit.
With the equation, V=IR, we know that current is inversely proportional to resistance. The overall voltage cannot change.
Since voltage doesn’t change and resistance decreases, current must increase.

Since the switch is now closed, there are two pathways for current to pass through: 1st one being through the resistor and second being through the switch.
This means that Q has the full voltage. Therefore, Q increases and R decreases.

The answer is H.