Free Electromagnetism MCQs with Answers
1,176 Electromagnetism MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.
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Read the Electromagnetism notesFree MDCAT chapter notes with key terms1,176 questions · page 44 of 59
- A. In the negative x direction
- B. In the negative y direction
- C. In the positive y direction
- D. In the negative z direction
Explanation: Option (D) is correct.Step by Step explanation:The velocity of electron is in negative X axis direction.v→ = - v îThe magnetic field is…
Correct answer: In the negative z direction- A. North
- B. South
- C. East
- D. West
Explanation: Explanation is given below:The resultant force is directed towards east.
Correct answer: East- A. 1 x 10^-3 repulsive
- B. 4 x 10^-5, repulsive
- C. 1 x 10^-3 attractive
- D. 4 x 10^-5, atractive
Explanation: Force per unit length beween two current carrying straight wires=combining equations F = ILB and B = μ I/2(pi)r
Correct answer: 4 x 10^-5, atractive- A. North
- B. South
- C. East
- D. West
Explanation: The current is in the direction from east to west so current is in that direction, placing your thumb in this direction and then curling…
Correct answer: South- A. 30N
- B. 0.3N
- C. 300N
- D. Zero
Explanation: F = ILB sinθ = (10)(0.2)(0.3) sin 30° = 0.3 N
Correct answer: 0.3N- A. 0.13A
- B. 1.0A
- C. 2.0A
- D. 4.0A
Explanation: BL = μ₀ I ⇒ I = BL / μ₀ = 2πr B / μ₀= 2πr B / (4π × 10⁻⁷) = r B / (2 × 10⁻⁷) = (2 × 10⁻²)(2 × 10⁻⁵) / (2 × 10⁻⁷) = 2 A.
Correct answer: 2.0A- A. AC current
- B. Pulsating DC current
- C. DC current
- D. All of these
Explanation: When charges are in motion, they have current (AC, DC or pulsating DC); magnetic field is produced around a current carrying conductor due…
Correct answer: All of these- A. 2F/9
- B. 2F/3
- C. 4F/9
- D. 4F/3
Explanation: When the two parallel long wires carry the same current and repel each other with a force F per unit length we have:F₁ / ℓ = I² B μ₀ / (2…
Correct answer: 4F/3- A. Megnetic flux density
- B. Megnetic field lines
- C. Megnetic flux
- D. Both A and B
Explanation: Note, the magnetic flux is a scalar quantity, while the magnetic field and area are bivectors.
Correct answer: Both A and B- A. MA VA < MB VB
- B. MA VA > MB VB
- C. MA<MB and VA<VB
- D. MA=MB and VA=VB
Explanation: When a charged particle is moving at right angle to the magnetic field, then a force acts on it which behaves as a centripetal force and…
Correct answer: MA VA > MB VB- A. The α-particle will be bent in a circular path with a small radius than that of the proton
- B. The radius of the path of the α-particle will be greater than that of the proton
- C. The α- particle and the proton will be bent in a circular path with the same radius
- D. The α- particle and the proton will go through the field in a straight line
Explanation: Given than Kₚ = KₐWe know that r = mv/qB = (2mK)^(1/2)/qB∴ rₚ = (2mₚ Kₚ)^(1/2) / qₚ B and rₐ = (2mₐ Kₐ)^(1/2) / qₐ BNow rₚ/rₐ = √[(mₚ/mₐ)…
Correct answer: The α- particle and the proton will be bent in a circular path with the same radius- A. 1mN
- B. 0.5mN
- C. 4mN
- D. 0.25mN
Explanation: F = (μ₀ / 4π) * (2 i₁ i₂ / a) × l = 10⁻³ NWhen current in both the wires is doubled, thenF' = (μ₀ / 4π) * 2 (2i₁ × 2i₂) / a × l = 4 × 10⁻³ N
Correct answer: 4mN- A. qBr/2πm
- B. qBr/2π
- C. qB/2πm
- D. qB/2πrm
Explanation: q v B = m v² / r⇒ q B = m v / r = m (r ω) / r = m (2 π f)⇒ f = q B / (2 π m)
Correct answer: qB/2πm- A. 9.4 x 10^-2m
- B. 19.5 x 10^-2m
- C. 9.5 x 10^2m
- D. 1cm
Explanation: e v B = mv² / r ⇒ e B = mv / rr = mv / eB = (9.1 × 10⁻³¹)(2 × 10⁷) / (1.6 × 10⁻¹⁹)(1.2 × 10⁻³) = 9.4 × 10⁻² m.
Correct answer: 9.4 x 10^-2m- A. Toward the magnet
- B. Downward
- C. Away from the magnet
- D. Upward
Explanation: Option D is correct. If the motion of the current is near the north pole, the wire will be pushed upwards.
Correct answer: Upward- A. Is inversely proportional to radial distance
- B. Obeys inverse cube law
- C. Obeys inverse square law
- D. Varies exponentially
Explanation: The magnetic field due to straight conductor is given as B=μoI/2πr where r is distance of any point P from the straight conductor, at…
Correct answer: Is inversely proportional to radial distance- A. A
- B. B
- C. C
- D. D
Explanation: Explanation is given below:(r = √2mV/e B or r = √2mV/eB2)
Correct answer: C- A. Be unaffected by the field
- B. Slow down
- C. Speed up
- D. Follow a right-handed corkscrew path
Explanation: When an electron travels due north through a region of uniform magnetic field B that is also directed due north, the electron will not…
Correct answer: Be unaffected by the field- A. Mass of an electron
- B. Earth's megnetic field
- C. Charge of an electron
- D. Charge to mass ratio of an electron
Explanation: Thomson found the same charge-to-mass ratio regardless of the metal used to make the cathode and the anode.
Correct answer: Charge to mass ratio of an electron- A. Always
- B. Never
- C. If the particle is moving across the field lines
- D. If the particle is moving along the field lines
Explanation: The magnetic field exerts a force on the particle in a particular condition.
Correct answer: If the particle is moving across the field lines