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 39 of 59
- A. Electric, Mechanical
- B. Mechanical , Electric
- C. Mechanical, Potential
- D. Not enough information
Explanation: An electric generator converts mechanical energy into electrical energy.
Correct answer: Mechanical , Electric- A. Bue
- B. Bq/u
- C. Bu/q
- D. Zero
Explanation: In case above the magnetic field and velocity are parallel , so angle between them will be zero if put it in equation for the force…
Correct answer: Zero763. Henry is unit of
- A. Self inductance only
- B. Mutual inductance
- C. both a and b
- D. emf
Explanation: The henry (symbolized H) is the Standard International ( SI ) unit of inductance
Correct answer: both a and b- A. 1.6 Wb
- B. 0.16 Wb
- C. 16 Wb
- D. 0 Wb
Explanation: Magnetic flux=BA cos θ As the question states, it is placed in the 'x-y plane', implying that the angle between the magnetic field and the…
Correct answer: 0 Wb- A. Maximum
- B. Minimum
- C. Zero
- D. Independent
Explanation: When the current is "zero", the induced EMF would also be "zero". And if the EMF is "zero" then naturally magnetic flux would also be…
Correct answer: Zero- A. Proton
- B. Alpha particle
- C. Photon
- D. All of these
Explanation: A: A proton has a charge-mass ratio of 1 C/amu. B: An alpha particle has a charge-mass ratio of 2/4=1/2 C/amu.
Correct answer: Proton- A. f∝N
- B. f∝N-1
- C. f∝N2
- D. f∝N-2
Explanation: The magnetic flux ø is directly related to the number of turns of the coil N.Flux = BA cos(θ)And B = uo n IHence flux = uo n I A…
Correct answer: f∝N- A. circular
- B. straight line
- C. spherical
- D. helical
Explanation: If velocity of charged particle and magnetic field are at an angle of 90 then path will be circular and if the angle is other than 90 then…
Correct answer: helical- A. 0.01 Wb
- B. 0 Wb
- C. 8.66 x 10^-3 Wb
- D. 0.86 Wb
Explanation: When the plane is parallel to the field, the angle is 90°. As cos 90° = 0 so flux= ø= 0 Wb.
Correct answer: 0 Wb770. In an A.C. generator, an increase in the number of turns in the coil does which of the following?
- A. Increases emf
- B. Decreases emf
- C. Makes the emf zero
- D. Maintains the emf at a constant value
Explanation: Option A is correct since in an A.C. generator, the emf increases as the number of turns in the coil increases because the emf is directly…
Correct answer: Increases emf- A. Faraday's Law
- B. Lenz's Law
- C. Ohm's Law
- D. Kirchoff's Law
Explanation: Lenz' law states that, "The direction of induced current is always so as to oppose the change which causes the current."ε = -N…
Correct answer: Lenz's Law- A. Circular
- B. A straight line
- C. Spherical
- D. Helical
Explanation: The force in a magnetic field is given by, F=qVBsinθ, where if θ is smaller than 90° and greater than 0°, it moves in a helical path…
Correct answer: Helical- A. Voltage
- B. Electric field
- C. Magnetic field
- D. All of these
Explanation: According to Faraday's law, an increase in the number of loops will result in an increase in the induced EMF or voltage.
Correct answer: Voltage- A. Is=10 Ip
- B. Ns=Np/10
- C. Ns=10Np
- D. Vs=Vp/10
Explanation: The turns ratio of a transformer describes the number of wire turns on the input versus the number of turns on the output.The ratio of…
Correct answer: Ns=10Np- A. Increased core loss
- B. Increased I2R loss
- C. Interference with communication circuits
- D. All of these options are correct
Explanation: Harmonics in a transformer can result in all of the given options being correct.
Correct answer: All of these options are correct- A. Deflect upwards
- B. Deflect downwards
- C. Speed up
- D. Speed down
Explanation: Option C is correct since the magnetic and electric fields are parallel to each other so the charge will speed up.
Correct answer: Speed up- A. Electric induction
- B. Magnetic induction
- C. Electromagnetic induction
- D. Dipole induction
Explanation: Electromagnetic induction is the process of generating an electric current in a conductor by placing it in a changing magnetic field.
Correct answer: Electromagnetic induction- A. Core length increases
- B. Core area increases
- C. Flux density decreases
- D. Flux density increases
Explanation: Attraction capacity depends on the magnetic field strength which is called magnetic flux density.
Correct answer: Flux density increases- A. Changing magnetic field in space
- B. Changing magnetic field in time
- C. Changing flux with space
- D. Constant magnetic field
Explanation: Motional emf is produced when a current-carrying conductor is moved in an external magnetic field.
Correct answer: Changing magnetic field in time- A. Changes direction
- B. Changes strength
- C. Changes polarity
- D. No change occurs
Explanation: If magnetic flux in a region is constant i.e no change in flux linkage, it implies that the magnetic field present in the region is…
Correct answer: No change occurs