JEE Main20249 Apr 2024Morning ShiftPhysicsCurrent ElectricityActual
A galvanmeter has a coil of resistance 200 with a full scale deflection at 20 A . The value of resistance to be added to use it as an ammeter of range (0-20) mA is ;
Options
- A0.40
- B0.20
- C0.50
- D0.10
Correct answer
B. 0.20
Step-by-step solution
aligned & G =200 & i _ g =20 A & i = i _ g ( G S +1 ) & 20 10⁻³=20 10⁻⁶ ( 200 ~S +1 ) & 200 ~S =999 & S 0.2 aligned