Question

A circuit contains an ammeter, a battery of $30V$ and a resistance of $40.8$ ohm all connected in series. If the ammeter has a coil of resistance $480$ ohm and a shunt of resistance $20$ ohm, the reading in the ammeter will be

• A. $1A$
• B. $0.5A$
• C. $0.25A$
• D. $1A$

Answer 1

The correct option is B $0.5A$


$R_{eff}=40.8+\frac{480\times 20}{480+20}=40.8+19.2=60\Omega I=\frac{V_{eff}}{R_{eff}}=\frac{30}{60}=0.5A$