JAMB - Physics (2000 - No. 33)
A cell of internal resistance 1Ω supplies current to an external resistor of 3Ω. The efficiency of the cell is
25%
33%
50%
75%
Paskaidrojums
Efficiency = Output/input x 100/1
Efficiency = 3/(3+1) x 100/1
= 3/4 x 100/1 = 75%
Efficiency = 3/(3+1) x 100/1
= 3/4 x 100/1 = 75%