JEE Main202311 Apr 2023Morning ShiftPhysicsCurrent ElectricityActual
The current sensitivity of moving coil galvanometer is increased by 25 % . This increase is achieved only changing in the number of turns of coils and area of cross section of the wire while keeping the resistance of galvanometer coil constant. The percentage change in the voltage sensitivity will be:
Options
- A+ 25 %
- B- 50 %
- C- 25 %
- DZero
Correct answer
A. + 25 %
Step-by-step solution
The current sensitivity is given as S i = N B A C . The voltage sensitivity is S v = N A B C R , where R is the galvanometer resistance. Since the resistance is constant, Δ S i = Δ S v Hence, the percentage change in voltage sensitivity is, Δ S v = + 25 % .