Question

Assertion: On moving a distance two times the initial distance away from an infinitely long straight uniformly charged wire the electric field reduces to one-third of the initial value.

Reason: The electric field is inversely proportional to the distance from an infinitely long straight uniformly charged wire.

Options

• Assertion is correct, reason is correct; reason is a correct explanation for assertion.

• Assertion is correct, reason is correct; reason is not a correct explanation for assertion.

• Assertion is correct, reason is incorrect.

• Assertion is incorrect, reason is correct.

Answer 1

Assertion is incorrect, reason is correct.

Explanation:

For an infinite line charge, E ∝ `1/r`. At 2r, the field becomes `E/2`, not `E/3`. So the assertion is wrong, but the reason is correct.