Question

Two moving coil galvanometers G₁ and G₂ are identical except that they have 50 turns and 20 turns and resistances of 10 Ω and 1 Ω, respectively. Perform necessary calculations to check which one has greater voltage sensitivity.

Answer 1

Current sensitivity = `θ/I = (NBA)/C`

Voltage sensitivity = `θ/V`

= `(θ/I)/V`

= `(NBA)/(CR)`

`β_1 ∝ N_1/R_1 = 50/10` = 5

`β_2 ∝ N_2/R_2 = 20/1` = 20

Since 20 > 5, G₂ has greater voltage sensitivity.