Moving Charges and Magnetism

Topics in this chapter

• Magnetic Force on Moving Charges
• Charged Particle Motion in Magnetic Fields
• Biot-Savart and Ampere’s Laws
• Magnetic Fields from Current-Carrying Conductors
• Force Between Parallel Currents
• Torque on Current Loops
• Moving-Coil Galvanometer

Cheat sheet

Practice questions

1. Question 1Q-B875E6

   A charged particle enters a uniform magnetic field with its velocity parallel to the field. The path it follows is:

   1. A.Circular
   2. B.Helical
   3. C.Straight line
   4. D.Parabolic
   See the answer and solution
2. Question 2Q-88D11E

   The SI unit of magnetic field (magnetic flux density) is:

   1. A.Weber
   2. B.Tesla
   3. C.Henry
   4. D.Gauss
   See the answer and solution
3. Question 3Q-381799

   The magnitude of the magnetic force on a charge q moving with speed v at angle theta to a magnetic field B is:

   1. A.qvB cos(theta)
   2. B.qvB sin(theta)
   3. C.qvB tan(theta)
   4. D.qvB
   See the answer and solution
4. Question 4Q-BEFBB8

   An electron (mass 9.1 x 10^-31 kg, charge 1.6 x 10^-19 C) moves at 3 x 10^7 m/s perpendicular to a magnetic field of 0.1 T. The radius of its circular path is approximately:

   1. A.1.7 x 10^-3 m
   2. B.1.7 x 10^-6 m
   3. C.3.4 x 10^-3 m
   4. D.1.7 x 10^3 m
   See the answer and solution
5. Question 5Q-9674A3

   In a cyclotron, the frequency of revolution of a charged particle is f = qB/(2 pi m). This frequency: [Previous Year NEET]

   1. A.Increases with the speed of the particle
   2. B.Depends on the radius of the orbit
   3. C.Is independent of the speed and radius of the particle
   4. D.Decreases as the magnetic field increases
   See the answer and solution