NTA Abhyas JEE Main2020PhysicsMagnetic Properties of MatterPractice
A moving coil galvanometer, having a resistance G produces full scales deflection when a current I g flows through it. It can be converted into an ammeter of range 0 to I 0 > I g by connecting a shunt of resistance R A to it. If it can also be converted into a voltmeter of range 0 to V = I 0 G by connecting a resistance R V to it in series, then which among the following is correct?
Options
- AR A R V = G 2 I 0 - I g I g and R A R V = I g I 0 - I g 2
- BR A R V = G 2 and R A R v = I g I 0 - I g
- CR A R v = G 2 and R A R v = I g I 0 - I g 2
- DR A R V = G 2 I g I 0 - I g and R A R V = I 0 - I g I g 2
Correct answer
C. R A R v = G 2 and R A R v = I g I 0 - I g 2
Step-by-step solution
( I 0 - I g ) R 4 = I g G and V 0 = I 0 G + R v I 0 = I 0 G + R A R A V 0 = I 0 G + R V V 0 = I 0 G ( given ) ⇒ I 0 G + R V = I g G + R A G R A R A G + R V R A = G 2 + R A G R V R A = G 2 R A = I g G I 0 - I g ; R V = I 0 - I g G I g R A R V = I g 2 I 0 - I g 2