Question

The diagram shows a resistor connected to a cell of e.m.f. $2V$ How much heat energy is produced in the resistor in six seconds?

• A. $2.5J$
• B. $4.8J$
• C. $10J$
• D. $60J$

Answer 1

Answer: (B)

$4.8J$

Answer is B.

The energy dissipated is calculated from the formula E = Pt. That is, E = VI*t.
Substituting I=V/R, we get, $E=\frac{V^2}{R}\times t$.
In this case, the resistance is 5 ohms and voltage is 2 V.
So, $E=\frac{2^2}{5}\times 6=4.8J$.
Hence, the heat energy is produced in the resistor in six seconds is 4.8 J.