Q107 / 180 · AIIMS 2017 · Physics

Assertion : An electrical bulb starts glowing instantly as it is switched on. Reason : Drift speed of electrons in a metallic wire is very large.

A
If both assertion and reason are true and reason is the correct explanation of assertion.
B
If both assertion and reason are true but reason is not the correct explanation of assertion.
Correct answer
C
If assertion is true but reason is false.
D
If both assertion and reason are false.

Solution

As the conductor is full of electrons, with slight drift anywhere the queue starts moving. As a result bulb starts glowing instanty. Drift velocity of electrons in a good conductor is very low.

Hence, the correct answer is option: 'C'.

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