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 48 of 59
- A. N.A2/m
- B. N.A/m
- C. N.m2/A
- D. N.m/A
Explanation: 1 Weber (Wb) = 1 N·m/AIn the International System of Units (SI), the Weber is defined as the amount of magnetic flux that produces one…
Correct answer: N.m/A- A. Maximum
- B. Zero
- C. Minimum
- D. None of these
Explanation: The force on a charged particle moving parallel to a magnetic field is zero.When a charged particle moves parallel to the magnetic field…
Correct answer: Zero- A. Circular path
- B. To any closed path
- C. Rectangular path
- D. None of these
Explanation: Ampere's law is a fundamental principle in electromagnetism and is applicable to any closed path.
Correct answer: To any closed path- A. Magnetization
- B. Magnetic flux density
- C. Magnetic field intensity
- D. All of these
Explanation: Magnatic flux density or flux density B=Φe/A
Correct answer: Magnetic flux density- A. Mass
- B. Charge
- C. Energy
- D. Momentum
Explanation: The Lenz's law is also a statement of law of conversation of energy that can be conventially applied to the circuits involving induced…
Correct answer: Energy- A. Uniform magnetic field
- B. Uniform magnetic and electric field
- C. Uniform electric field
- D. All of these
Explanation: The correct answer is Uniform magnetic field. According to Faraday's law of electromagnetic induction, an electromotive force (EMF) is…
Correct answer: Uniform magnetic field- A. 44V
- B. 220V
- C. 4.4V
- D. 11000V
Explanation: In a transformer, the voltage ratio between the secondary and primary coils is equal to the turns ratio.
Correct answer: 11000V948. The direction of induced current is always so as to oppose the change which causes the current is:
- A. Faraday's law
- B. Ohm's law
- C. Len's law
- D. Kirchhoff's Ist rule
Explanation: According to Lenz's law, "The direction of induced current is always so as to oppose the change which causes the current".
Correct answer: Len's law- A. Eddy currents
- B. Electric resistance
- C. Hysteresis
- D. Inductance
Explanation: The insulation between lamination sheets should be perfect so as to stop the flow of eddy currents.
Correct answer: Eddy currents- A. The flux is zero
- B. The flux is maximum
- C. The flux is half its maximum value
- D. The derivative of the flux with respect to time is zero
Explanation: When the magnetic flux through the rectangular loop is zero the emf is maximum.
Correct answer: The flux is zero- A. Move the slide of the rheostat R quickly to the right
- B. Move coil P toward coil Q
- C. Move coil Q toward coil P
- D. Open S
Explanation: When "S" is closed the magnetic flux will be in increasing order in coil Q and galvanometer shows left deflection.
Correct answer: Open S- A. Move it in +x direction
- B. Move it in -y direction
- C. Move it in +y direction
- D. Move it in -x direction
Explanation: When circular loop of wire moves in +x direction, the magnetic flux will decrease.
Correct answer: Move it in +x direction- A. There is a steady reading in G as long as S is closed
- B. A motional emf is generated when S is closed
- C. The current in the battery goes through G
- D. There is a current in G just after S is opened or closed
Explanation: The explanation is: Option D) There is a current in G just after S is opened or closed is correct.
Correct answer: There is a current in G just after S is opened or closed- A. Zero
- B. Counter clockwise
- C. Clockwise
- D. Depends on I1 or I2
Explanation: The explanation is: As I2 is constant, so, there will be no induction due to I2 in the loop.
Correct answer: Counter clockwise955. For transmission of electricity to far off places, from the A.C. power generation via we always use:
- A. Step down transformer
- B. Transformer with several secondaries
- C. Step up transformer
- D. All of these
Explanation: The explanation is: A step-up transformer increases the voltage while decreasing the current.
Correct answer: Step up transformer- A. Energy
- B. Voltage
- C. Power
- D. All of above
Explanation: The explanation is: A transformer is an electrical device used to change a given alternating emf into a large or small alternating emf.
Correct answer: Voltage- A. High current and low voltage is used
- B. Same voltage and current is used
- C. High voltage and low current is used
- D. High voltage and high current is used
Explanation: The explanation is: In a step up transformer when the voltage across the secondary is raised, the value of current is reduced.
Correct answer: High voltage and low current is used- A. Counterclockwise
- B. Clockwise
- C. Zero
- D. Up the left edge and from right to left along the top edge
Explanation: As the square loop or wire lies in the plane of the page and decreasibg magnetic fiel is directed into the page.
Correct answer: Clockwise- A. Zero
- B. Clockwise
- C. Counter clockwise
- D. Clockwise in the left side and counterclockwise in the right side
Explanation: As the constant current carrying wire is moving towards the rectangular loop, it causes an increased magnetic flux in the loop.
Correct answer: Counter clockwise- A. Small area
- B. Large area
- C. No area
- D. Moderate area
Explanation: The explanation is: The core of the transformer should be assembled from the laminated sheets of a material whose hysteresis loop area is…
Correct answer: Small area