A cell of internal resistance 1Ω supplies current to an external resistor of 3Ω. The efficiency of the cell is
A
25%
B
33%
C
50%
D
75%
Verified Correct Answer: D.
Physical Principles & Numerical Solution
Efficiency = Output/input x 100/1
Efficiency = 3/(3+1) x 100/1
= 3/4 x 100/1 = 75%
Source: Myschool Past Questions Archive (Record #1501)