Two moving coil meters, M₁ and M₂ have the following particulars: 

R₁ = 10 Ω, N₁ = 30, A₁ = 3.6 x 10^-3 m² and B₁ = 0.25 T

R₂ = 14 Ω, N₂ = 42, A₂ = 1.8 x 10^-3 m² and B₂ = 0.50 T

( The spring constants are identical for the two meters.)
The ratio of current sensitivity (M₂ to M₁) is: