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 18 of 59
- A. 20 x 10³ wb/m²
- B. 1.28 wb/m²
- C. 5 x 10⁻⁵ wb/m²
- D. 0.8 wb/m²
Explanation: Magnetic induction (B) is related to magnetic field strength (H) and permeability (μ) by the formula B = μH.
Correct answer: 1.28 wb/m²- A. 4 A
- B. 2.5 A
- C. 2 A
- D. 3.5 A
Explanation: The magnetic field strength (H) inside a solenoid is H = nI, where n is the number of turns per unit length.
Correct answer: 2 A- A. Slow down
- B. Move faster
- C. Move faster or slow down depending on which magnetic pole is facing the coil
- D. Continue moving unaffected
Explanation: As the magnet approaches the oscillating coil, the changing magnetic flux induces an eddy current in the coil.
Correct answer: Slow down- A. Diamagnetism
- B. Paramagnetism
- C. Ferromagnetism
- D. Both B and C
Explanation: Both paramagnetism and ferromagnetism are temperature-dependent. Paramagnetic susceptibility is inversely proportional to temperature…
Correct answer: Both B and C- A. 10 mH
- B. 15 mH
- C. 25 mH
- D. 5 mH
Explanation: The induced emf is given by ε = -M(dI/dt). First, find dI/dt = 10(100π)cos(100πt). The maximum value of dI/dt is 1000π A/s.
Correct answer: 5 mH- A. Parallel to the wire
- B. Clockwise
- C. Perpendicular to the wire
- D. Anti-clockwise
Explanation: Using the right‐hand rule for a straight current‐carrying wire: if you point your thumb in the direction of the current(top→bottom), the…
Correct answer: Clockwise- A. Magnetic flux
- B. Motional emf
- C. Induced emf
- D. Magnetic induction
Explanation: The magnetic force on a charge moving in a magnetic field is given by: F=qv×BMagnetic induction is defined as the magnetic force per unit…
Correct answer: Magnetic induction- A. Energy
- B. Speed
- C. Velocity
- D. Kinetic Energy
Explanation: The magnetic force is always perpendicular to the particle's velocity. This force changes the direction of the velocity vector but does no…
Correct answer: Velocity- A. Remain stationary
- B. Move towards each other
- C. Move away from each other
- D. Move at right angles to each other
Explanation: Two parallel currents flowing in the same direction attracteach other due to the magnetic fields they produce.If the currents were in…
Correct answer: Move towards each other- A. Speed
- B. Direction of motion
- C. Energy
- D. All of these
Explanation: The magnetic force is a deflecting force that acts perpendicularly to the velocity of a charged particle.
Correct answer: Direction of motion- A. Current
- B. Force
- C. EMF
- D. Temperature
Explanation: The right-hand palm rule is a mnemonic used to determine the direction of the magnetic force on a positive charge moving in a magnetic…
Correct answer: Force- A. Watt
- B. Tesla
- C. ms-1
- D. Weber
Explanation: In a velocity selector, the electric force (qE) balances the magnetic force (qvB), so qE = qvB.
Correct answer: ms-1- A. Lorentz force
- B. Self inductance
- C. Magnetic flux
- D. Magnetic induction
Explanation: Magnetic induction, also known as magnetic flux density (B), is defined as the force per unit current per unit length on a wire placed…
Correct answer: Magnetic induction- A. Repel each other
- B. Have no effect upon each other
- C. Attract each other
- D. They cancel out their individual magnetic fields
Explanation: Using the right-hand grip rule, the magnetic field from one wire at the location of the other wire creates a force.
Correct answer: Repel each other- A. Equal to that of an electron
- B. Greater than that of an electron
- C. Smaller than that of an electron
- D. Sometimes smaller and sometimes greater
Explanation: The charge (e) has the same magnitude for both a proton and an electron.
Correct answer: Smaller than that of an electron- A. In downward direction
- B. Into the paper
- C. In upward direction
- D. Out of the paper
Explanation: For a positive charge with v→(right) and B out of page, v×B= down (−y). An electron has negative charge, so its force is opposite (upwards).
Correct answer: In upward direction- A. Tesla (T)
- B. Weber (Wb)
- C. Ampere per meter (A/m)
- D. Gauss (G)
Explanation: Magnetic flux density, often simply called the magnetic field (B), measures the strength of a magnetic field.
Correct answer: Tesla (T)- A. Energy
- B. Charge
- C. Momentum
- D. Mass
Explanation: Lenz's law states that induced current flows in a direction that opposes change in magnetic flux.This opposition prevents the system from…
Correct answer: Energy- A. 1.758 x 10¹¹ C kg⁻¹
- B. 9.58 x 10⁷ C kg⁻¹
- C. 1.628 x 10¹ C kg⁻¹
- D. Zero
Explanation: The charge-to-mass ratio is calculated as q/m. Since a neutron is a neutral particle, its charge (q) is zero.
Correct answer: Zero- A. E=evB
- B. E=vB
- C. B=eE/v
- D. E=evB/2
Explanation: For the electron to pass undeflected, the electric force (Fₑ = qE) must be equal in magnitude and opposite in direction to the magnetic…
Correct answer: E=vB