Question:

When a current of 5mA is passed through a galvanometer having a coil of resistance 15Ω, it shows full scale deflection. The value of the resistance to be put in series with the galvanometer to convert it into a voltmeter of range 0-50V is:

4.005×10³Ω

2.045×10³Ω

1.985×10³Ω

2.535×10³Ω

The correct option is B
1.985×10³Ω
V=ig(Rg+Rs)
50=(5×10⁻³)(15+Rs)
15+Rs=10/5×10⁻³=2×10³
Rs=2000-15Ω
Rs=1985Ω
Rs=1.985kΩ
Option (2) is correct.