Question

A moving coil galvanometer can be converted into an ammeter by :

• A. introducing a shunt resistance of large value in series.
• B. introducing a shunt resistance of small value in parallel.
• C. introducing a resistance of small value in series.
• D. introducing a resistance of large value in parallel.

Answer 1

Answer: (B)

introducing a shunt resistance of small value in parallel.

To utilise a galvanometer (G) as an ammeter, there is the difficulty in measurement of current due to the sensitivity of galvanometer and also the connection of galvanometer with a very large resistance in series that may change the value of current in the circuit. To overcome these difficulties one attaches a small resistance $r_s$ called shunt resistance in parallel with the galvanometer coil as shown in the figure.