Two tangent galvanometers, A and B have their number of turns in the ratio `3:1` and diameters of coils in the ratio `4:1`. Explain with reason (i) Which galvanometer has greater reduction factor? (ii) Which galvanometer shows greater deflection, when both are connected in series to a d.c. source?

Answer

(i) A, (ii) B

Explanation

As the two tangent galvanometer are connected in series, they carry the same current.
`:. I_1=(2rH)/(mu_0n_1)tan theta_1=I_2=(2rH)/(mu_0n_2)tantheta_2`
`:. n_1/n_2=(tan theta_1)/(tan theta_2)=(tan 35^@)/(tan 45^@)=(0*7)/(1)=(7)/(10)`