Drift Velocity

Q. Two wires A and B of the same material, having radii in the ratio 1 : 2 and carry currents in the ratio 4 : 1. The ratio of drift speeds of electrons in A and B is:

1. 16 : 1
2. 1 : 16
3. 1 : 4
4. 4 : 1

Q. The average velocity with which the electrons moves inside a conductor is called the velocity.

1. conduct
2. random
3. drift

Q. There is an insulator rod of length L and of negligible mass with two small balls of mass m and electric charge Q attached to its ends. The rod can rotate in the horizontal plane around a vertical axis crossing it ata distance L/4 from one of its ends. At first the rod is in unstabel equilbrium in a gorizontal umifrom electric field of field strenght E. Then we gently displace it from this position. Determine the maximim velocity attained by the ball taht is closer to the axis in the subsequent motion

Q.

What do you mean by drift speed of electrons? And how to calculate it

Q.

A copper wire with a diameter of $1.02mm$ carries a current of $1.7A$. The drift velocity ($v_d$)of electrons in the wire is? (The number density of electrons in copper = $8.5\times {10}^{28}{m}^3$.)

1. $1.25mm/sec$

2. $0.15mm/sec$

3. $1.5mm/sec$

4. $2.5mm/sec$

Q.

If current in a current carrying wire is $1.5A$, number of free electrons per unit volume is $8\times {10}^{28}{m}^3$ and area of cross section is $5m{m}^2$. Drift velocity of electrons will be:

1. $0.02mm{s}^{-1}$

2. $2mm{s}^{-1}$

3. $0.2mm{s}^{-1}$

4. None of these

Q. How is it so that a bulb flows as soon as it is switched on, though the electrons drift at a speed of 1 or 2 cm/s?

Q. In the derivation of equation for Gauss law Whan electric charge is situated outside the body the electric flux produced by the charge is 0. Why is it so

Q. A current '$I$' flows through a metallic wire of radius '$r$' and the free electrons in it drift with a velocity $v_d$. Calculate the drift velocity of the free electrons through the wire of the same material, having double the radius, when some current flows through it.

Q. what is meant by magnitude?

Q. A current I flows through a uniform wire of diameter d when the mean electron drift velocity is
V. The same current will flow through a wire of diameter d/2 made of the same material if the
mean drift velocity of the electron is:

1. v/4
2. v/2
3. 2v
4. 4v

Q.

how is it so that a bulb glows as soon as it is switched on; though the electrons drift at a speed of about 1 or 2 cm/s.

Q. The plot represents the flow of current through a wire at three different times. The ratio of charges flowing through the wire at different times is

1. $2:1:2$
2. $1:3:3$
3. $1:1:1$
4. $2:3:4$

Q. Question 2 (c)
In Activity 13.7, how do we think the displacement of rod AB will be affected if
(iii) length of the rod AB is increased?

Q. Match the terms with their relative descriptions.

1. Average velocity
2. Free electrons
3. Atom arrangement
4. Electron flow

Q. Match the terms with their relative descriptions.

1. Free electrons
2. Atom arrangement
3. Average velocity
4. Electron flow

Q. Match the terms with their relative descriptions.

1. Average velocity
2. Electron flow
3. Free electrons
4. Atom arrangement