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 13 of 59
- A. remain stationary
- B. get displaced away from the magnet
- C. get displaced towards the magnet
- D. nothing can be said
Explanation: C is correct. When a magnet is approached towards a metallic circular ring, an electromotive force (EMF) is induced in the ring due to the…
Correct answer: get displaced towards the magnet- A. the same everywhere around the conductor
- B. inversely proportional to the distance from the conductor
- C. inversely proportional to the square of the distance from the conductor
- D. inversely proportional to the cube of the distance from the conductor
Explanation: C is correct.The strength of the magnetic field (B) due to a long straight conductor is inversely proportional to the square of the…
Correct answer: inversely proportional to the square of the distance from the conductor- A. number of turns of the coil should be increased
- B. strength of the magnetic field should be increased
- C. area of the coil should be increased
- D. all of these
Explanation: D is correct.To increase the current sensitivity of a moving coil galvanometer, you can increase the number of turns of the coil (N)…
Correct answer: all of these- A. 1.6 T
- B. 0.2 T
- C. 0.8 T
- D. 0.1 T
Explanation: B is the correct answer. As explained earlier, doubling the distance (r) from the wire divides the magnetic field strength by 2 due to the…
Correct answer: 0.2 T- A. I is proportional to tan(θ)
- B. I is proportional to θ
- C. I is proportional to θ^2
- D. I is proportional to θ^1/2
Explanation: A is the correct answer. In a moving coil galvanometer, the deflection of the coil (θ) is related to the electric current (I) by the…
Correct answer: I is proportional to tan(θ)- A. moves in the direction of the field
- B. moves opposite to the field
- C. starts spinning
- D. remains stationary
Explanation: C is the correct answer. In a strong magnetic field, a stationary charged particle, such as an electron, experiences a magnetic force…
Correct answer: starts spinning- A. the number of turns in the coil is increased
- B. magnet is taken in the form of a horseshoe
- C. poles pieces cut concave
- D. coil is wound on an aluminum frame
Explanation: C is the correct answer. To make the field radial in a moving coil galvanometer, the poles pieces are cut concave to provide a radial…
Correct answer: poles pieces cut concave- A. q(E+v×B)
- B. q(E−v×B)
- C. q(E+v⋅B)
- D. q(E×B+v)
Explanation: A is the correct answer.The Lorentz force F experienced by a charged particle moving with velocity v in an electric field E and a magnetic…
Correct answer: q(E+v×B)- A. 1
- B. 5
- C. 20
- D. 10
Explanation: D is the correct answer. The formula for induced emf (E) due to change in current in a coil is given by E=−LΔI/Δt , where L is the…
Correct answer: 10- A. parallel to the field
- B. at 45° to the field
- C. perpendicular to the field
- D. none of them
Explanation: C is the correct answer.The emf induced in a coil rotating in a uniform magnetic field is maximum when the plane of the coil is…
Correct answer: perpendicular to the field- A. NBA/ω
- B. ) NBA/ω^2
- C. NBA⋅ω
- D. NBA⋅ω^2
Explanation: C is the correct answer. The maximum value of the emf (Emax ) induced in a coil rotating in a uniform magnetic field is given by Faraday's…
Correct answer: NBA⋅ω- A. 2 V
- B. 0.2 V
- C. 20 V
- D. 200 V
Explanation: D is the correct answer.The emf (E) induced in a coil is given by E=−M⋅ΔI/Δt , where M is the mutual inductance, ΔI is the change in…
Correct answer: 200 V- A. 5 mH
- B. 5000 H
- C. 5 H
- D. zero
Explanation: A is the correct answer.The inductance (L) is given by L=−E⋅Δt/ΔI , where E is the induced emf, Δt is the change in time, and ΔI is the…
Correct answer: 5 mH- A. must decrease
- B. must remain constant
- C. must increase
- D. can either increase or decrease
Explanation: D is the correct answer.According to Faraday's law of electromagnetic induction, an emf is induced in a coil when there is a change in the…
Correct answer: can either increase or decrease- A. shape of the loop
- B. area of loop
- C. value of current
- D. magnetic field
Explanation: D is the correct answer The torque (τ) acting on a current-carrying loop in a uniform magnetic field depends on the angle between the…
Correct answer: magnetic field- A. strength of the magnet
- B. length of the conductor
- C. speed of the conductor
- D. all of these
Explanation: D is the correct answer The motional electromotive force (emf) induced in a conductor moving in a magnetic field depends on the strength…
Correct answer: all of these- A. magnetic field increases
- B. magnetic saturation level in the core increases
- C. residual magnetism in the core decreases
- D. loss of energy in the core due to eddy current decreases
Explanation: D is the correct answer .The core of a dynamo is laminated to reduce eddy current losses.
Correct answer: loss of energy in the core due to eddy current decreases- A. Eddy current losses
- B. Hysteresis losses
- C. iron losses
- D. heat losses due to resistance
Explanation: A is the correct answer . Laminating the core in a transformer is primarily done to reduce eddy current losses.
Correct answer: Eddy current losses- A. from left to right
- B. from right to left
- C. clockwise
- D. anticlockwise
Explanation: D is the correct answer. According to the right-hand rule, when the current flows through a conductor out of the plane of the paper, the…
Correct answer: anticlockwise- A. north pole
- B. south pole
- C. neutral
- D. may be north or south pole
Explanation: B is the correct answer.:According to the right-hand grip rule, if the current flows in an anticlockwise direction in a loop, the magnetic…
Correct answer: south pole