JAMB - Physics (1988 - No. 29)
A cell of internal resistance 2 ohms supplies current to a 6 ohms resistor. The efficiency of the cell is
12.0%
25.0%
33.3%
75.0%
Giải thích
Efficiency = \(\frac{IR}{I(R + r)}\) x 100
= \(\frac{6}{I(2 + 6)}\) x 100
= 75%
= \(\frac{6}{I(2 + 6)}\) x 100
= 75%