99 Percentile Qs Bank for JEE MainPhysicsExperimental Physics
A galvanometer of resistance 25 Ω is connected to a battery of 2 V along with a resistance of 3000 Ω . In this case, a full-scale deflection of 30 units is obtained in the galvanometer. In order to reduce this deflection to 10 units , how much more resistance (in Ω ) should be added to the circuit in series?
Correct answer
6050
Step-by-step solution
The deflection in a galvanometer is directly proportional to the current. First case: 30 x = 2 25 + 3000 Second case: 10 x = 2 25 + 3000 + R ⇒ 3 = 25 + 3000 + R 25 + 3000 On solving, we get R = 6050 Ω