Question

A galvanometer coil has a resistance of 15 Ω and the metre shows full scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A?

Answer 1

Resistance of the galvanometer coil, G = 15 Ω

Current for which the galvanometer shows full scale deflection,

= 4 mA = 4 × 10⁻³ A

Range of the ammeter is 0, which needs to be converted to 6 A.

Current, I = 6 A

A shunt resistor of resistance S is to be connected in parallel with the galvanometer to convert it into an ammeter. The value of S is given as:

Hence, a shunt resistor is to be connected in parallel with the galvanometer.