Physicshard · Past Paper
A 220V, 100W bulb and a 220V, 40W bulb are connected in series to a 220V supply. Which bulb will glow brighter?
A100W bulb
B40W bulb
CBoth will glow equally
DNeither will glow
✓ Correct Answer: B — 40W bulb
The 40W bulb has higher resistance (R = V^2/P). In series, P_dissipated = I^2R. Higher R means higher power dissipation for the 40W bulb.
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