Two tangent galvanometers differ only in the matter of number of turns in the coil. On passing current through the two joined in series, the first shows a deflection of `35^@` and the other shows `45^@` deflection. Compute the ratio of their number of turns. Take `tan35^@=0*7`

Answer

`7:10`

Explanation

When two tangent galvanometers are connected in series, current passing through them is the same i.e. `I_1=I_2`
`(2rH)/(mu_0n_1)tantheta_1=(2rH)/(mu_0n_2)tan theta_2 :. n_1/n_2=(tan theta_1)/(tan theta_2)`