Ammeter MCQ - Practice Questions with Answers

Ammeter

It is a device used to measure current and always connected in series with the circuit

• In the above circuit, A represents the ammeter.

• Conversion of galvanometer into ammeter: Connect a low resistance (shunt) in parallel to the galvanometer.

Gs
- The equivalent resistance of the combination is $\overline{G+s}$ where G is the galvanometer resistance and s is the shunt resistance.
- Required shunt

$
s=\frac{i_g G}{\left(i-i_g\right)} . \text { Where } \mathrm{i} \text { is the total current, } i_g \text { is the galvanometer current }
$

- To pass $n^{\text {th }}$ part of main current through galvanometer that is If $i_g=i / n$

Then the required shunt resistance

$
s=\frac{G}{(n-1)}
$