MHT CET202618 April 2026Morning ShiftPhysicsCurrent ElectricityActual
By connecting a resistance of 980 in series with a galvanometer, it is converted into a voltmeter of a certain range. When the resistance of 470 is connected in series, the range is halved. The resistance of the galvanometer is
Options
- A30
- B40
- C50
- D60
Correct answer
B. 40
Step-by-step solution
Let the resistance of the galvanometer be G and its full-scale deflection current be I_g . When a resistance of 980 is connected in series, the range of the voltmeter is V . V = I_g(G + 980) When a resistance of 470 is connected in series, the range is halved to V 2 . V 2 = I_g(G + 470) Dividing the first equation by the second equation: 2 = G + 980 G + 470 2G + 940 = G + 980 G = 40 Answer: 40