(a) How much current will an electric bulb draw from a 220 V source, if the resistance of the bulb filament is 1200 `Omega `? (b) How much current will an electric heater coil draw from a 220 V source, if the resistance of the heater coil is 100 `Omega`?

Explanation

(a) We are given V = 220 V, R = 1200 `Omega `.
From Eq. (12.6), we have the current I = 220 V/1200 `Omega ` = 0.18 A.
(b) We are given, V = 220 V, R = 100 `Omega `. From Eq. (12.6), we have the current I = 220 V/100 `Omega ` = 2.2 A. Note the difference of current drawn by an electric bulb and electric heater from the same 220 V source!