Question

If the current sensitivity of a galvanometer is doubled then its voltage sensitivity will be

• A. (a) Doubled
• A. (b) Halved
• A. (c) Unchanged
• A. (d) Four times

Answer 1

(c) Current sensitivity of galvanometer is deflection per unit current i.e.

…… (i)

Similarly voltage sensitivity is deflection per unit voltage i.e.

…… (ii)

From (i) and (ii)

Voltage sensitivity = current sensitivity ×

$\frac { 1 } { \text { resis tance } }$

Now if current sensitivity is double, then the resistance in the circuit will also be double since it is proportional to the length of the wire, then voltage sensitivity

= (2× current sensitivity ×(current sensitivity)× $\frac { 1 } { \text { resis tance } }$

Hence voltage sensitivity will remain unchanged.