A cell of e.m.f. 1.5v is connected in series with a resistor of 3(Omega). A high resistance voltmeter connected across the cell registers only 0.9v. Calculate the internal resistance of the cell
-
A.
5.0(Omega) -
B.
4.5(Omega) -
C.
2.4(Omega) -
D.
2.0(Omega) -
E.
1.8(Omega)
Correct Answer: Option A
Explanation
I = (frac{V}{R} = frac{0.9}{3} = 3)
r = (frac{E}{I} = frac{1.5}{0.3} = 5)