15) i) False, ii) False, iii) True, iv) False, v) False
Since the circuit is in parallel, the voltage in the voltmeter and the bulb will remain the same.
The voltmeter and the bulb will have the same voltage. Due to Ohm’s Law, current will also remain the same.
Closing S2 will open a new pathway for current to flow in the bulb in the lowest branch. This will cause the total resistance of the circuit to fall. Since current is inversely proportional to resistance, current will increase.
The voltage and current across A3 will remain the same.
If S3 is closed, there will be negligible resistance in the ammeters. So the reading in ammeter A2 will definitely NOT increase.