Question

From current electricity, to convert a galvanometer into an ammeter, a shunt is given. Find the resistance of the galvanometer.

• A. \( R_g \)
• B. \( R_s \)
• C. \( R_g + R_s \)
• D. \( \frac{R_g}{R_s} \)

Hint:

For converting a galvanometer into an ammeter, place a shunt in parallel to bypass part of the current.

Answer 1

The Correct Option is C

To convert a galvanometer into an ammeter, a shunt resistance \( R_s \) is placed in parallel with the galvanometer. This allows the ammeter to measure large currents without damaging the galvanometer. The total current through the circuit is shared between the galvanometer and the shunt, with the galvanometer current determined by its resistance. Using the relation for parallel resistances: \[ I = \frac{V}{R_g + R_s}, \] where \( R_g \) is the resistance of the galvanometer, and \( R_s \) is the shunt resistance. Thus, the total resistance of the system is the sum \( R_g + R_s \).