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
-
A.
2.0(Omega). -
B.
3.0(Omega). -
C.
5.0(Omega). -
D.
6.0(Omega).
Correct Answer: Option A
Explanation
(frac{V}{R} = frac{E}{R + r})
(frac{0.9}{3} = frac{1.5}{3 + r})
r = 2(Omega).