Welcome to your Chapter 4 Moving Charges and Magnetism MCQs

1.
The magnetic moment of a current I carrying circular coil of radius r and number of turns N varies as

2.
A current carrying loop is placed in a uniform magnetic field. The torqe acting on it does not depend upon

3.
A charged particle is moving on circular path with velocity v in a uniform magnetic field B, if the velocity of the charged particle is doubled and strength of magnetic field is halved, then radius becomes

4.
Two a-particles have the ratio of their velocities as 3 : 2 on entering the field. If they move in different circular paths, then the ratio of the radii of their paths is

5.
Two charged particles traverse identical helical paths in a completely opposite sense in a uniform magnetic field B =B0k

6.
A circular coil of radius 4 cm and of 20 turns carries a current of 3 amperes. It is placed in a magnetic field of intensity of 0.5 weber/m². The magnetic dipole moment of the coil is

7.
An electron is projected with uniform velocity along the axis of a current carrying long solenoid. Which of the following is true?

8.
In a cyclotron, a charged particle

9.
If a charged particle moves through a magnetic field perpendicular to it

10.
A circular current loop of magnetic moment Mis in an arbitrary orientation in an external magnetic field B. The work done to rotate the loop by 30° about an axis perpendicular to its plane is

11.
The maximum current that can be measured by a galvanometer of resistance 40 Ω is 10 mA. It is converted into voltmeter that can read upto 50 V. The resistance to be connected in the series with the galvanometer is

12.
What torque acts on a 50 turn coil of 200 cm² area carrying a current of 20 A held with its axis at right angles to a uniform magnetic field of 0.2 T ?

13.
What is the maximum torque on a rectangular coil of area 4 cm × 80 cm of 400 turns, when carrying a current of 103 A in a magnetic field of 0.2 T?

14.
Under which of these conditions, the torque acting on the current carrying loop is minimum?

15.
Identify the factor on which the torque on a planar current loop does not depend.

16.
Calculate the torque on a 500 turn rectangular coil of length 20 cm and breadth 10 cm, carrying a current of 30 A, when placed making an angle of 60° with a magnetic field of 0.5 T?

17.
What is the magnetic field inside a pipe?

18.
The magnetic field due to a current carrying circular loop of radius 4 cm at a point on the axis at a distance of 7 cm from the center is 48 μT. What will be the value at the center of the loop?

19.
Which of the following particles cannot be accelerated using a cyclotron?

20.
There are two conductors X and Y carrying a current I and moving in the same direction. p and q are two electron beams also moving in the same direction. Will there be attraction or repulsion between the 2 conductors and between the two electron beams separately?