The ammeter shown in figure consists of a` 480(omega)`coil connected in parallel to a` 20 (omega)` shunt. Find the reading of the ammeter.

Explanation

The equivalent resistance of the ammeter is
`((480(Omega))(20(Omega)))/(480(Omega)+20(Omega))=19.2(Omega).`
the equivalent resistance of the circuit is
`140.8(Omega)+19.2(Omega)=160(Omega).`
the current is `i=(20V)/(160(Omega)=0.125A.`
this current goes through the ammeter and hence the reading of the ammeter is 0.125A.