A cell of internal resistance 2 ohms supplies current to a 6 ohms resistor. The efficiency of the cell is
A
12.0%
B
25.0%
C
33.3%
D
75.0%
Verified Correct Answer: D.
Physical Principles & Numerical Solution
Efficiency = \(\frac{IR}{I(R + r)}\) x 100
= \(\frac{6}{I(2 + 6)}\) x 100
= 75%
Source: Myschool Past Questions Archive (Record #28392)