NTA Abhyas JEE Main2020PhysicsCurrent ElectricityPractice
An ammeter, voltmeter and a resistor are connected in series to a cell and the readings are noted as I and V . If another resistor R is connected in parallel with a voltmeter, then
Options
- AI and V increase
- BI increases
- CI and V will remain same
- DI decreases
Correct answer
B. I increases
Step-by-step solution
When the resistor R is connected in parallel with voltmeter, the effective resistance in the circuit decreases because 1 R = 1 R 1 + 1 R 2 Therefore current, I = V R increases. As I increases, potential across R increases and hence potential across voltmeter decreases. Hence reading of voltmeter decreases.