JAMB - Physics (2018 - No. 51)
The resistance of a 40W car head lamp, drawing current from a 12V battery is ____.
0.3Ω
3.3Ω
3.6Ω
4.8Ω
Shpjegimi
Power delivered to head lamp = \(\frac{V_2}{R}\)
= 40W
R = \(\frac{V_2}{40}\)
= \(\frac{(12 × 2)}{40}\)
= 3.6Ω