Start learning →

MP Board Class 12 (MPBSE) Electromagnetism — practice questions — page 2

Explore 36 free Electromagnetism questions in MP Board Class 12 (MPBSE) Physics. Open each question or exercise to read its content, reference answers and available explanation.

Practise Electromagnetism with Quill →

Electromagnetism questions and exercises with answers

Showing questions 31–36 of 36.

A 0.1 m radius loop carries 5 A. The magnetic field at a point on its axis 0.1 m from the centre is approximately (μ₀ = 4π × 10⁻⁷ T·m/A)Read the answer and worked solution →A bar magnet with N pole pointing right is placed near a circular current loop whose magnetic moment also points right. The interaction isRead the answer and worked solution →Cyclotrons are not used to accelerate electrons becauseRead the answer and worked solution →A long solenoid has 1000 turns per metre and carries 2 A. The magnetic field strength inside isRead the answer and worked solution →A square coil of side 0.1 m, with 50 turns, carries 1 A in a 0.2 T field. The maximum torque on the coil isRead the answer and worked solution →A charge q moves with velocity v through a region with electric field E and magnetic field B. The net electromagnetic force on it isRead the answer and worked solution →

Worked practice questions

A 0.1 m radius loop carries 5 A. The magnetic field at a point on its axis 0.1 m from the centre is approximately (μ₀ = 4π × 10⁻⁷ T·m/A)

  1. 1.6 × 10⁻⁵ T
  2. 2.2 × 10⁻⁵ T
  3. 3.1 × 10⁻⁵ T
  4. 1.1 × 10⁻⁵ T
Show answer and solution

Correct answer: D. 1.1 × 10⁻⁵ T

1. Use B = μ₀IR² / (2(R²+x²)^(3/2)). 2. With R = x = 0.1 m: R²+x² = 0.02 m²; (0.02)^(3/2) ≈ 0.002828. 3. Numerator: μ₀IR² = 4π × 10⁻⁷ × 5 × 0.01 ≈ 6.28 × 10⁻⁸. 4. B = 6.28 × 10⁻⁸ / (2 × 0.002828) ≈ 1.11 × 10⁻⁵ T. _Source: syllabus Physics Ch 4 "Moving Charges and Magnetism", §4.6_

Open this question →

A bar magnet with N pole pointing right is placed near a circular current loop whose magnetic moment also points right. The interaction is

  1. attractive
  2. repulsive
  3. zero force
  4. torque but no force
Show answer and solution

Correct answer: A. attractive

1. A current loop acts as a magnetic dipole; aligning moments means the loop's south pole faces the magnet's north pole. 2. Opposite poles attract in magnetic interactions. 3. The non-uniform field of the bar magnet exerts a net force on the loop. 4. The force pulls the loop toward the bar magnet, so the interaction is attractive. _Source: syllabus Physics Ch 4 "Moving Charges and Magnetism", §4.10.2_

Open this question →

Cyclotrons are not used to accelerate electrons because

  1. Electrons have negative charge
  2. Electron mass grows too fast with energy
  3. Magnetic field cannot deflect electrons
  4. Electrons spin too rapidly for resonance
Show answer and solution

Correct answer: B. Electron mass grows too fast with energy

1. Cyclotron operation depends on a constant frequency f = qB/(2πm). 2. As electrons gain energy, their relativistic mass m grows rapidly because the rest mass is very small. 3. The cyclotron frequency therefore drifts, breaking resonance with the AC accelerating voltage. 4. Heavier ions tolerate higher energies before relativistic effects matter; for electrons, betatrons or synchrotrons are used instead. _Source: syllabus Physics Ch 4 "Moving Charges and Magnetism", §4.4.2_

Open this question →

How to practise

  1. Choose a Electromagnetism question and try to work out your answer.
  2. Open the question to check the correct answer and read its worked solution.
  3. Continue in the app for bite-sized lessons, explanations and review with Quill. You can start without creating an account.

More Physics topics

Moving Charges and MagnetismMagnetismRay OpticsRay Optics and Optical InstrumentsAtomsOpticsRay and Wave OpticsMagnetism & EMI