A cell of e.m.f. 1.5V is connected in series with a resistor of resistance 3.0\(\Omega\). A voltmeter connected across the cell registers 0.9V. Calculate the internal resistance of the cell
-
2.0\(\Omega\).
- 3.0\(\Omega\).
- 5.0\(\Omega\).
- 6.0\(\Omega\).
The correct answer is: A
Explanation
\(\frac{V}{R} = \frac{E}{R + r}\)\(\frac{0.9}{3} = \frac{1.5}{3 + r}\)
r = 2\(\Omega\).