In an electric circuit current of 3 A is drawn for 5 minutes from a cell of e.m.f. 1 V. The work done by the source is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 900 J
The emf is the work done by the source per unit charge, so the work is emf times the charge delivered, \( W = \varepsilon I t \), with the time in seconds.
\( \displaystyle t = 5\,\mathrm{min} = 300\,\mathrm{s} \)
\( \displaystyle W = \varepsilon I t = 1\,\mathrm{V} \times 3\,\mathrm{A} \times 300\,\mathrm{s} = 900\,\mathrm{J} \)