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Assertion : Current flows in a conductor...

Assertion : Current flows in a conductor only when there is an external electric field within the conductor.
Reason: The drift velocity of the electrons is directly proportional to the electric field.

A

If both assertion and reason are true and reason is the correct explantion of assertion.

B

If both assertion and reason are true and reason is not the correct explantion of assertion.

C

If assertion is false but reason is true.

D

If assertion is true but reason is false.

Text Solution

Verified by Experts

The correct Answer is:
A
In the absence of electric field, the electrons move randomly in all directions. Hence there is no net motion of electrons and no current flow in the conductor. But in the presence of electric field, electrons move in a particular direction. Each electron experiences a force in the direction opposite to that of the electric field and moves from the negative end to the positive end of the conductor. Thus there is a current flow. The drift velocity,
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Knowledge Check

  • Assertion: A current flows in a conductor only when there is an electric field within the conductor: Reason: The drift velocity of electron in presence of electric field decreases.

    A
    Both (A) and (R) are true and (R) is the correct explanantion 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.

  • STATEMENT-1: A current flows in a conductor only when there is an electric field within the conductor. Because STATEMENT-2: The drift velocity of electron in presence of electric field decreases.

    A
    Statement-1 is True , Statement-2 is True , Statement-2 is a correct explanation for Statement-1.
    B
    Statement-1 is True , Statement-2 is True , Statement-2 is NOT a correct explanation for Statement-1.
    C
    Statement-1 is True , Statement-2 is False
    D
    Statement-1 is False , Statement-2 is True

  • The average velocity of electrons in a conductor in the absence of electric field is

    A
    `10^(2)`m/s
    B
    `10^(-2)`m/s
    C
    `10^(4)` m/s
    D
    `10^(-4)` m/s

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    How does electric current flow along a conductor, when electric field is applied along the length of conductor ?

    What happens when a conductor is placed in an external electric field?

    When current flows through a conductor, then the order of drift velocity of electrons will be

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