An electric cell has an internal resistance of 2 ohms. A current of 0.5A is found to flow when a resistor of 5 ohms resistance is connected across it. What is the electromotive force of the cell?
-
A.
5 volts -
B.
3.5 volts -
C.
2.5 volts -
D.
1 volts -
E.
10 volts
Correct Answer: Option B
Explanation
E.m.f. = I(R + r) = 0.5(2+5) = 3.5 volts