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 38 of 59
- A. BLI
- B. B2LI
- C. BLI2
- D. Zero
- E. Infinity
Explanation: Force on a current-carrying conductor is equal to BIL.
Correct answer: BLI- A. 0
- B. 90
- C. 180
- D. 45
Explanation: Magnetic flux is the product of the magnetic induction and vector area element Flux= B.ΔA Flux=BΔAcosθ The maximum value(=1) of cosθ…
Correct answer: 0- A. 1 Henrys
- B. 2 Henrys
- C. 3 Henrys
- D. 4 Henrys
- E. 6 Henrys
Explanation: Initial current, I1=5.0AFinal current, I2=0AChange in current, dl=I1−I2=5ATime taken for the charge, t=0.1sAverage emf, e=200VFor self…
Correct answer: 4 Henrys- A. Self induction
- B. Mutual magnetic induction
- C. Electrostatics
- D. Mutual charging
Explanation: The transformer works based on the mutual induction principle between two coils.
Correct answer: Mutual magnetic induction- A. If it is either moving parallel to the magntic field intensity.
- B. If it is either moving antiparallel to the magnetic field intesity.
- C. Charge particle moves perpendicular to the velocity vector.
- D. Both A and B.
Explanation: Minimum force or no force acts on the charge particle if it is either moving parallel or antiparallel to the magnetic field intensity.
Correct answer: Both A and B.- A. 178.33 units
- B. 186.67 units
- C. 192.77 units
- D. 200 units
Explanation: Total flux = B x A and to get B, divide total flux/area hence B = 28/0.15 = 186.67 units.
Correct answer: 186.67 units747. If the supply frequency of a transformer increases, the secondary output voltage of the transformer:
- A. Increases
- B. Decreases
- C. Remains unchanged
- D. Any of above
Explanation: If the supply frequency of a transformer increases, the secondary output voltage of the transformer increase.
Correct answer: Increases- A. Electron
- B. Proton
- C. Neutron
- D. All of these options are correct
Explanation: Lorentz Force is only valid for protons, because the direction of conventional current is assumed to be the movement of positive…
Correct answer: Proton- A. Moves upward
- B. Move downward
- C. Move randomly
- D. Moves in straight line
Explanation: Correct option is B. Cathode rays are deflected by a magnetic field seen to bend downwards.
Correct answer: Move downward- A. The electric field must not be zero
- B. The magnetic field must not be zero
- C. The electric field may or may not be zero
- D. The magnetic field may or may not be zero
- E. Option A and D are correct.
Explanation: Correct options are A) and D). Electromagnetic force is the force on charged particles due to both electric field and magnetic field.
Correct answer: Option A and D are correct.- A. Using a permanent magnet
- B. Electric current
- C. Using a temporary magnet
- D. Using a permanent magnet or electric current
Explanation: If an electric current is passed through a long coil of wire (a solenoid ) a magnetic field is produced which is the same shape as that of…
Correct answer: Using a permanent magnet or electric current- A. 1256 wb
- B. 12.96 wb
- C. 1190 wb
- D. 1426 wb
Explanation: Flux = magnetic field × area = 100×π×r2 = 100×3.14×4=1256wb
Correct answer: 1256 wb- A. Distance
- B. Current on them
- C. Charge on them
- D. None of these
Explanation: According to Ampere's law, the magnetic force between two parallel current-carrying wires is directly proportional to the current flowing…
Correct answer: Current on them- A. Increases core loss
- B. Increases I^2R loss
- C. Interference with communication circuits
- D. All of the above
Explanation: When harmonics are present in a transformer, they can cause an increase in core loss.
Correct answer: All of the above- A. Scalar quantity
- B. Vector quantity
- C. Sometimes scalar sometimes vector
- D. None of these
Explanation: Magnetic flux density is a vector quantity. It has both magnitude and direction.
Correct answer: Vector quantity- A. AC generator
- B. DC generator
- C. Battery
- D. Transformer
Explanation: Mutual induction is the ability of an inductor in one circuit to induce a voltage in another circuit.
Correct answer: Transformer- A. It causes less amount of power loss
- B. It reduces the possibility of power theft
- C. High voltage waves travel faster
- D. Generators produce electrical energy at high voltage
Explanation: High voltage is used to increase efficiency and low current is used to reduce resistance which causes less power loss, hence Option A is…
Correct answer: It causes less amount of power loss- A. Eddy current loss
- B. Core loss
- C. Copper loss
- D. Friction loss
Explanation: Friction losses are involved with rotating parts of a machine. A transformer is a static device i.e.
Correct answer: Friction loss- A. 0 degree
- B. 90 degree
- C. 45 degree
- D. 60 degree
Explanation: Magnetic flux is maximum when the angle between the magnetic field and the normal to the plane of finite area is 0∘.
Correct answer: 0 degree- A. Strength
- B. Flux
- C. Magnetic flux density
- D. Density
Explanation: The definition of H is H = B/ − M, where B is the magnetic flux density, a measure of the actual magnetic field within a material…
Correct answer: Magnetic flux density