Question

A $5.0$ amp current is setup in an external circuit by a $6.0$ volt storage battery for $6.0$ minutes. The chemical energy of the battery is reduced by

• A. $1.08 \times 10^{4}J$
• B. $1.08 \times 10^{4}\,J$
• C. $1.8 \times 10^{4}\,J$
• D. $1.8 \times 10^{4}$ volt

Answer 1

Answer: (A)

Given: $V =6.0$ volts $ I =5.0 A$
Time for which current flows, $t =6 \times 60=360 s$
Electric power spent by the battery $P = V I$
$\Rightarrow P=6 \times 5=30 W$ or $30 J / s$
Electric energy spent by the battery $E = P$ ower $\times$ time
$
\therefore E =30 J / s \times 360 s =1.08 \times 10^{4} J
$
This electric energy came from the chemical energy stored within the battery. So the energy of the battery is reduced by $1.08 \times 10^{4} J$.