NTA Abhyas JEE Main2020PhysicsCurrent ElectricityPractice
The deflection in a galvanometer falls to 1 4 th of its initial value when it is shunted by 3 Ω . If an additional shunt of 2 Ω is connected in parallel to earlier shunt, the deflection in the galvanometer falls to 1 n th . What is the value of n ?
Correct answer
8.5
Step-by-step solution
I − I 4 = 3 I 4 R I 4 = 3 I 4 × 3 R = 9 Ω I = I 1 + I 2 ...(1) 9 I 1 = 6 5 I 2 ...(2) ⇒ 15 2 I 1 = I 2 Using equation (1) I = I 1 + 15 2 I 1 = 17 2 I 1 I 1 = 2 I 17 I 1 = I 17 / 2 = I 8.5