An electric bulb is rated as 100W-250V. What information does it convey? Calculate:
(i) The resistance of its filament while glowing, and
(ii) The current through the filament of the bulb.
Given: p = 100W, V = 250volt.
(i) The resistance of filament, R = V2/P =(250)2/100 = 625Ω.
(ii) The current through the filament, I = P/V = 1000/250 = 4A.
