Question

A galvanometer has a resistance of 100 Ω and its full scale deflection current is 0.2 mA, what resistance should be added to it to have a range of 0-10 V?

Answer 1

Data: G = 100 Ω, I_g = 2 × 10⁻⁴ A and V = 10 V

The required resistance to be connected in series with the galvanometer is

∴ R_s = `V/I_g - G`

= `10/(2 xx 10^-4) - 100`

= 50000 − 100

= 49900 Ω

= 49.9 kΩ