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 34 of 59
- A. Upwards
- B. Downwards
- C. Towards the 'N' pole of the magnet
- D. Towards the 'S' pole of the magnet
Explanation: We can determine the direction of the force on the current-carrying wire using Fleming's Left-Hand Rule.Step-by-step explanation:Magnetic…
Correct answer: Downwards- A. Increases away from conductor
- B. Decreases away from conductor
- C. Increases towards conductor
- D. Decreases and then increases towards conductor
Explanation: The difference between the magnetic field lines increases as shown below:
Correct answer: Increases away from conductor- A. Tumors and inflamed tissues
- B. Blood cells
- C. Skin cells
- D. Bone structures
Explanation: MRI is used to identify images of tumours and inflamed tissues. Blood cells are identified by smear stain, skin cells are identified under…
Correct answer: Tumors and inflamed tissues664. A solenoid is cut into two halves. Magnetic induction due to the same current in each half will be:
- A. Half of the original
- B. Double of the original
- C. Same as original
- D. Four times of the original
Explanation: Magnetic field due to a solenoid, B=μo n I, where n= l/N. So, if the length and number of turns become half for a solenoid, n remains the…
Correct answer: Same as original- A. Clockwise
- B. Anti-clockwise
- C. Vertically upward
- D. Vertically downward
Explanation: The magnetic field generated by a long straight current-carrying conductor can be determined using the right-hand rule.
Correct answer: Clockwise- A. Zero
- B. 1 Newton
- C. 10-4 Newton
- D. 1 dyne
Explanation: The formula of Magnetic force is F=BIL sinθ F=1x 1 x 1 x 0 = 0 Since the wire is placed parallel to the magnetic field, No force acts on…
Correct answer: Zero- A. Parallel to the field
- B. Perpendicular to the field
- C. At 45˚ to the field
- D. None of the given options are correct
Explanation: According to Faraday's law when magnetic flux linking a circuit changes, an electromotive force is induced in the circuit proportional to…
Correct answer: Parallel to the field- A. Electron
- B. Proton
- C. Both experience same force
- D. Cannot be predicted
Explanation: F=q(V×B) F=qvBsin The formula infers that F∝v As both proton and electron have the same velocity they will experience the same value of…
Correct answer: Both experience same force- A. Northwards
- B. Southwards
- C. Vertically upwards
- D. Vertically downwards
Explanation: Apply the rule as shown in the following image.By this, we get a downward direction.
Correct answer: Vertically upwards- A. The force acts radially inwards
- B. The force acts radially downwards
- C. The force acts in the direction of motion
- D. No force acts
Explanation: Consider the diagram of magnetic field shown and observe the magnetic field lines.Option D) When an electron moves along the axis of…
Correct answer: No force acts- A. Strength of magnetic field
- B. Speed of the conductor
- C. Length of conductor
- D. All answers are correct
Explanation: The factors on which motional emf depends are the magnetic field and velocity and length of the rod. Thus option D is the correct answer.
Correct answer: All answers are correct- A. Scalar
- B. Vector
- C. Vector in some cases
- D. Scalar in some cases
Explanation: Magnetic flux, which tells us about the number of field lines that cross the surface, is a scalar. It is the dot product of two vectors.
Correct answer: Scalar- A. Magnetic field lines
- B. Electric field lines
- C. Optical field lines
- D. Gravitational field lines
Explanation: The tesla (T) is the unit of magnetic flux density also called magnetic B-field strength.
Correct answer: Magnetic field lines- A. Maximum magnetic flux
- B. Initial magnetic flux
- C. Change in magnetic flux
- D. The rate of change of magnetic flux
Explanation: According to Faraday's laws of electromagnetic induction, induced emf in a coil depends upon the number of turns and the rate of change of…
Correct answer: The rate of change of magnetic flux- A. North pole only
- B. South pole only
- C. Both south and north poles
- D. Magnetism will be removed
Explanation: Even if a magnet is broken in half, each half has one north pole and one south pole.
Correct answer: Both south and north poles- A. Low DC voltage
- B. High DC voltage
- C. Battery voltage
- D. AC voltage
Explanation: Transformers can only work with AC voltage.
Correct answer: AC voltage- A. Open loops
- B. Closed loops
- C. Straight lines
- D. Vertlcal loops
Explanation: Eddy currents are loops of electrical current induced within conductors by a changing magnetic field in the conductor according to…
Correct answer: Closed loops- A. Constant
- B. Decrease
- C. Increase
- D. Continuously changing
Explanation: Direction of current changes as the coil is rotated.
Correct answer: Continuously changing679. Which derived unit below is equivalent to the SI unit for magnetic field strength, the tesla, T?
- A. N m / A
- B. N A / m
- C. N / A m
- D. A m / N
Explanation: Force(F) = B(magnetic field strength) x I (current) x L (length / distance)hence , the SI units for each of the above mentioned properties…
Correct answer: N / A m- A. 3.15 m
- B. 4.25 m
- C. 9.93 m
- D. 17.77 m
- E. 19.91 m
Explanation: r = (m * v) / (q * B)Given:m = 9.109 x 10^-31 kgv = 2.0 x 10^7 m/sq = -1.6 x 10^-19 CB = 1.20 x 10^-3 TNow, let's calculate the radius…
Correct answer: 9.93 m