Drift Speed

Q. The drift velocity of the free electrons in a conducting wire carrying a current ${}^{\prime }{i}^{\prime }$ is $v$. If in a wire of the same metal, but of double the radius and the current to be $2i,$ then the drift velocity of the electrons will be ?

1. $\frac{v}{4}$
2. $\frac{v}{2}$
3. $v$
4. $4v$

Q. A current $\left(I\right)$ flows through a uniform wire of diameter $\left(d\right),$ when the mean drift velocity is $V$. If same current flows through a wire of diameter $d/2$ made of the same material, then the mean drift velocity of the electron is

1. $\frac{V}{4}$
2. $\frac{V}{2}$
3. $4V$
4. $2V$

Q.

An ammeter has a range of $\left(0-3\right)amperes$ and there are $30divisions$ on its scale. Calculate the least count of the ammeter.

Q. An electric current of $8\text{A}$ exists in a metal wire of cross section ${10}^{-4}{\text{m}}^2$ and length $2\text{m}$. The drift speed of the free electrons in the wire will be (Given $n=5\times {10}^{28}{\text{m}}^{–3})$

1. $2\times {10}^{-3}\text{m/s}$
2. $1\times {10}^{-3}\text{m/s}$
3. $2\times {10}^{-2}\text{m/s}$
4. $1\times {10}^{-5}\text{m/s}$

Q.

To obtain displacement current of 0.2 a between the plates of a capacitor of capacity 0.5 μf, what should be the rate of change of potential difference between the plates?

Q. The drift velocity of the free electrons in a conducting wire carrying a current ${}^{\prime }{i}^{\prime }$ is $v$. If in a wire of the same metal, but of double the radius and the current to be $2i,$ then the drift velocity of the electrons will be ?