The magnetic field at the center of a moving coil galvanometer is 0.25 T. The coil has an area of 0.2 m^(2) and has 28 turns. If the current senstivity of the MCG is to be increased by 25%, then the number of turns in the coil should be incrased by_________.Assume that all other things are kept constant.

Options

A. 7
B. 8
C. 10
D. 12

Answer

A

Explanation

`s_i=(nAB)/K therefore (S_2)/(S_1)=(n^(2)AB)/K xx K/(n_1AB)=n_2/N_i 5/4=(n_2)/(28) therefore n_2=35 therefore` no. of turns should be increased by 7.