Question

1. A bulb drawn 0.4 A current from a 3 V battery in 6.5 minutes. Calculate the

(a) number of charge that flows in the circuit.

(b) resistance of the bulb filament.

(c) energy dissipated in the bulb.

Answer 1

Part (a)

$I=\frac{Q}{t}$

$0.4=\frac{Q}{60×6.5}$

$Q=156C$

Part (b)

$V=IR$

$R=\frac{3}{0.4}=7.5\Omega$

Part (c)

$E=QV$

$=156×3$

$=468J$