JEE Main202310 Apr 2023Morning ShiftPhysicsMagnetic Effects of CurrentActual
Given below are two statements: Statement I: If the number of turns in the coil of a moving coil galvanometer is doubled then the current sensitivity becomes double. Statement II: Increasing current sensitivity of a moving coil galvanometer by only increasing the number of turns in the coil will also increase its voltage sensitivity in the same ratio In the light of the above statements, choose the correct answer fro
Options
- AStatement I is true but Statement II is false
- BStatement I is false but Statement II is true
- CBoth Statement I and Statement II are false
- DBoth Statement I and Statement II are true
Correct answer
A. Statement I is true but Statement II is false
Step-by-step solution
For a moving coil galvanometer, N i A B = k θ The current sensitivity is given by S i = N A B k So, if N is doubled then, the current sensitivity is also doubled. The voltage is given by V = B N A R k θ The voltage sensitivity is given by S v = N A B k R As, N is increased, R also increases. So, the voltage sensitivity does not change as N R remains constant.