A potential difference V is applied across a conductor of length ‘l’. How is the drift velocity affected when V is doubled and l is halved?

The formula for drift velocity is given as,

|vd| = eτ/mxE

However, we know that E = V/l

where V refers to the potential difference

l is the length of conductor.

Substituting this value of E in the drift velocity formula, we have:

|vd| = eτ/m(Vl)

Therefore, the drift velocity is proportional to the potential difference applied across the conductor.
The length of the conducting wire is inversely proportional to drift velocity. V becomes 2V when the potential difference applied across the conductor is doubled.
When the conductor’s length is half, l becomes l/2.

Putting these values in the drift velocity equation, we have:

|vd′|=eτ/m(4V/l)

On simplifying the equation further, we get:

|vd′|=4eτ/m(V/l)

We know that eτm(V/l)=|vd|

Substituting this in the above equation we get

|vd′|=4|vd|

Therefore, we can observe that when the potential difference of a conductor is doubled and the length of the conductor is half, the drift velocity increases by four times.

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A potential difference V is applied across a conductor of length ‘l’. How is the drift velocity affected when V is doubled and l is halved?

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3.
The resistance of a metal wire at \( 20^\circ \text{C} \) is \( 1.05 \, \Omega \) and at \( 100^\circ \text{C} \) is \( 1.38 \, \Omega \). Determine the temperature coefficient of resistivity of this metal.

5.
This ‘average velocity’ is found be few mm/s for currents in range of a few amperes. How then is current established almost the instant a circuit is closed ?

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A potential difference V is applied across a conductor of length ‘l’. How is the drift velocity affected when V is doubled and l is halved?

Related Questions

CBSE CLASS XII Related Questions

3. The resistance of a metal wire at \( 20^\circ \text{C} \) is \( 1.05 \, \Omega \) and at \( 100^\circ \text{C} \) is \( 1.38 \, \Omega \). Determine the temperature coefficient of resistivity of this metal.

5.This ‘average velocity’ is found be few mm/s for currents in range of a few amperes. How then is current established almost the instant a circuit is closed ?

Similar Physics Concepts

Comments

SUBSCRIBE TO OUR NEWS LETTER

3.
The resistance of a metal wire at \( 20^\circ \text{C} \) is \( 1.05 \, \Omega \) and at \( 100^\circ \text{C} \) is \( 1.38 \, \Omega \). Determine the temperature coefficient of resistivity of this metal.

5.
This ‘average velocity’ is found be few mm/s for currents in range of a few amperes. How then is current established almost the instant a circuit is closed ?