Question

An electric bulb works on the principle of:
(a) Archimedes
(b) heating effect of current
(c) magnetic effect of current
(d) none of these

Answer 1

Hint:In order to solve this problem we need to know that the heating effect is produced by current.

Complete answer:
When a current flows through a conductor, heat energy is generated in the conductor. The heating effects of electric current is produced.

An electric bulb works on the principle of hearing effect of current. It consists of a tungsten filament with a coating of thorium. This filament gets heated up to emit light when current passes through it.

Hence, the correct answer to the question is option (b).

Additional Information: When a current flows through a conductor, heat energy is generated in the conductor. The heating effects of electric current depend on three factors:
-The resistance of the conductor. A higher resistance produces more heat.
-The time for which the current flows. The longer the time the amount of heat production is high.
-Higher the current the amount of heat generation is also large.

Hence the heating effect produced by an electric current, $I$ through a conductor of resistance, $R$ for a time, $t$ is given by \[H = {I^2}Rt\]. This equation is the Joule’s equation of electrical heating.Joule’s law states the amount of heat production in a conductor is: Directly proportional to the square of electric current flowing through it, Is directly proportional to the resistance of the conductor, directly proportional to the time for which electric current flows through the conductor.

Note:While solving this question, one should have to know the heating effect of current in conductors. The factors on which heating of a conductor depends and factors responsible for it. For the further explanation refer to the above section.