Question

A galvanometer, with a scale divided into 150 equal divisions, has current sensitivity of 10 divisions per milliampere and voltage sensitivity of 2 divisions per millivolt. Find shunt for making ammeter of 6A.

• A. 1.25 × 10^–3W
• B. 12.5 × 10^–3W
• C. 125 × 10^–3W
• D. 0.125 × 10^–3W

Answer 1

Answer: (B)

12.5 × 10^–3W

Answer 2

$\left. \begin{array} { l } \mathrm { I } _ { \mathrm { g } } = 15 \mathrm {~mA} \\ \mathrm {~V} _ { \mathrm { g } } = 75 \mathrm { mV } \\ \mathrm { I } = 6 \mathrm {~A} \end{array} \right\}$ ̃ R_g = = 5W

S = $\frac { \mathrm { I } _ { \mathrm { g } } \mathrm { R } _ { \mathrm { g } } } { \mathrm { I } - \mathrm { I } _ { \mathrm { g } } }$ = 12.5 × 10^–3 W