Two moving coil meters, `M_1 `and `M_2` have the following particulars: `R_1` = `10Omega` , N_1 = 30. `A_1`= `3.6 xx 10^-3 m^2`, `B_1` = 0.25 T `R_2` = `14Omega` , `N_2` = 42, `A_2=1.8Xx10^-3 m^2`,`B_2`=0.50T (The spring constants are identical for the two meters). Determine the ratio of voltage sensitivity of `M_2 and M_1`.