JAMB - Physics (2024 - No. 104)
The efficiency of a cell with internal resistance of 2\(\Omega\) supply current to a 6\(\Omega\) resistor is
25%
50%
65%
75%
คำอธิบาย
Efficiency of a cell = \(\frac{R}{R + r }\) x 100
= \(\frac{6}{6+ 2 }\) x 100
= \(\frac{6}{8}\) x 100 = 75%