Question

Assertion : The electric bulb glows immediately when switch is on.
Reason : The drift velocity of electrons in a metallic wire is very high.

• A. Both (A) and (R) are true and (R) is the correct explanation of A.
• B. Both (A) and (R) are true but (R) is not the correct explanation of A.
• C. (A) is true but (R) is false
• D. (A) is false but (R) is true

Answer 1

The correct option is C (A) is true but (R) is false

Assertion is true.

When we switch on the bulb, it glows immediately.

But the Reason is false.

The drift velocity is very small, of the order of some $mm$.

Then-ever the bulb glows immediately since when switch is closed, all the electrons start drifting and so does the electron in direct nearby of bulb.

Thus instantly electron starts flowing through the bulb and it starts glowing.

Answer-(C)