WAEC - Physics (2022 - No. 29)
A lamp is rated 240 V, 60 W. Determine the resistance of the lamp when lit?
120\(\Omega\)
240\(\Omega\)
540\(\Omega\)
960\(\Omega\)
คำอธิบาย
P = 60w, V = 240v, R = ?
P = \(\frac{V^2}{R}\)
: 60 = \(\frac{240^2}{R}\)
→ R * 60 = 57,600
R = \(\frac{57,600}{60}\)
R = 960\(\Omega\)