Free Charged Particle in a Magnetic Field MCQs with Answers
62 Charged Particle in a Magnetic Field MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
A charged particle moving through a magnetic field experiences the Lorentz force, which is perpendicular to both its velocity and the field. The motion may be circular or helical, with questions involving radius, angular frequency, time period, and work done. A stationary charge feels no magnetic force.
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- A. At an angle of 30⁰.
- B. At an angle of 45⁰.
- C. Parallel to the field.
- D. Perpendicular to the field.
Explanation: The magnetic force experienced by a charged particle moving in a magnetic field is determined by the equation F = qvBsinθ, where θ is the…
Correct answer: Parallel to the field.- A. Electric force
- B. Centripetal force
- C. Magnetic force
- D. Gravitational force
Explanation: The magnetic force provides the necessary centripetal force to the charge particle. So, the charge particle moves in circular path
Correct answer: Centripetal force- A. r = \(\frac{mv}{eB}\)
- B. r = \(\frac{B}{mv}\)
- C. r = \(\frac{I}{v}\)
- D. r = \(\frac{I}{m}\)
Explanation: To find the radius of the circular path of an electron in a magnetic field, equate the magnetic force to the centripetal force.
Correct answer: r = \(\frac{mv}{eB}\)- A. α-particle
- B. Electron
- C. β-particle
- D. Neutron
Explanation: For a particle to be deflected it must have non-zero value for:B, q,vbut for neutron q=0 so F will also equal to zero and it will not get…
Correct answer: Neutron- A. 1:2:4
- B. 4:2:1
- C. 1:1:1
- D. 2:2:4
Explanation: p = mv, p = constant. Charge on proton, deuteron, and α-particle is +e, +e, and +2e respectively.
Correct answer: 1:2:4- A. Deflect towards North
- B. Deflect towards South
- C. Move straight
- D. Move in circular path
Explanation: If the particle is moving along the magnetic field, F=0. Hence the particle continues to move along the incident direction, in a straight…
Correct answer: Move straight- A. Deflect toward north
- B. Deflect toward south
- C. Move straight
- D. Move in circular path
Explanation: In this orientation, the magnetic force on the particle is perpendicular to its velocity, causing it to move in a straight line without…
Correct answer: Move straight- A. e/m =B r/E
- B. E/(B2r)
- C. E2/rB2
- D. B2/Er
Explanation: The currently accepted value for e/m is 1.758820 × 1011 C/kg. When an electron enters a region in which there is a uniform magnetic field…
Correct answer: E/(B2r)- A. F = BA cosϴ
- B. F = μo NI
- C. F = q (v x B)
- D. F = I (L x B)
Explanation: Explanation:For a charge moving in a magnetic field the force is directly proportional to the charge, velocity of the charge carrier and…
Correct answer: F = q (v x B)- A. 2 N
- B. Zero
- C. 8 N
- D. 4 N
Explanation: Explanation:The force experienced by a charge moving in a magnetic field is given by the formula: F = qvBsinθWhere q is the charge, v is…
Correct answer: Zero- A. 1.6 x 10^-19C
- B. 2.7 x 10^-19C
- C. 3.2 x 10^-19C
- D. 4.8 x 10^-19C
Explanation: The equation for this scenario is; Magnetic Force= Bqv sin(X) where B is the magnetic field strength, q is the charge and v is the…
Correct answer: 3.2 x 10^-19C- A. Only Magnitude
- B. Only direction
- C. Magnitude and direction
- D. Neither magnitude nor direction
Explanation: Electric forces change the magnitude and direction of velocity, as they exert a force on charged particles based on the electric field…
Correct answer: Only direction- A. An electric field only
- B. A magnetic field only
- C. Both magnetic and electric field
- D. Magnetic and gravitational field
Explanation: Magnetic and gravitational field: This option is incorrect. A moving electric charge does not generate a gravitational field.
Correct answer: Both magnetic and electric field- A. proton
- B. electron
- C. both will suffer greater defection
- D. None of these
Explanation: The deflection is inversely proportional to mass, so for an electron and a proton moving with the same velocity, an electron with lighter…
Correct answer: electron- A. Kinetic energy
- B. Magnitude of velocity
- C. Direction of velocity
- D. All of these
Explanation: When a charged particle enters a uniform magnetic field, the magnetic force acts perpendicular to the velocity of the particle.
Correct answer: Direction of velocity- A. F = qvB
- B. F = qE
- C. F = 0
- D. F = mv2/r
Explanation: When a charged particle moves parallel to a magnetic field, the force acting on it is zero because the angle between the velocity and…
Correct answer: F = 0- A. Both electric and magnetic field
- B. Both magnetic and gravitational field
- C. A magnetic field only
- D. An electric field only
Explanation: The definition of magnetic field: The region where a moving charge particle experiences a force, provided that it moves perpendicular to…
Correct answer: A magnetic field only- A. Circle
- B. Helix
- C. Ellipse
- D. Straight line
Explanation: The charged particle has a velocity that is neither perpendicular nor parallel (along) to the magnetic field, i.e it is moving with an…
Correct answer: Helix- A. Of magnitude B/E and parallel to B
- B. Of magnitude E/B and parallel to B
- C. Of magnitude B/E and perpendicular to both ⃑E and ⃑B
- D. Of magnitude E/B and perpendicular to both ⃑E and ⃑B
Explanation: If velocity must remain constant, the net force must be zero, so electric and magnetic forces must be equal.magnetic force = electric…
Correct answer: Of magnitude E/B and perpendicular to both ⃑E and ⃑B- A. Charged
- B. Charge/mass(e/m)
- C. Kinetic energy
- D. Mass
Explanation: The formula used in mass spectrometry is q/m = v/Br where q is the charge, m is mass, v is velocity, B is magnetic field strength, and r…
Correct answer: Charge/mass(e/m)