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 27 of 59
- A. Faraday's law
- B. Coulomb's law
- C. Lenz's law
- D. Ohm's law
Explanation: Lenz's law is based on the law of conservation of energy. It states that the induced electromotive force (EMF) will generate a current…
Correct answer: Lenz's law- A. Electric field
- B. Magnetic field
- C. Magnetic lines
- D. None of these
Explanation: The magnetic flux density is the magnetic filed lines that pass per unit area.Magnetic flux density = magnetic fieldMagnetic flux density…
Correct answer: Magnetic lines- A. Power
- B. Current
- C. Voltage
- D. Current and voltage
Explanation: A step-up transformer increases voltage while decreasing current and a step-down transformer decreases voltage increasing current.
Correct answer: Voltage524. Moving charges have:
- A. Electric field and magnetic field both
- B. None of these
- C. Magnetic field only
- D. Electric field only
Explanation: A moving charge generates both an electric field and a magnetic field. The electric field is due to the charge itself, as any charged…
Correct answer: Electric field and magnetic field both- A. 2 : 1
- B. 1 : 2
- C. 4 : 8
- D. None of these
Explanation: Vs / Vp = Ns / Np(Vs = secondary voltage, Vp = primary voltage, Ns = turns in secondary wire, Np = turns in primary wire)If Vs / Vp = 2…
Correct answer: 2 : 1- A. Current
- B. Voltage
- C. Neither current nor voltage
- D. Both current and voltage
Explanation: A transformer is a device that uses electromagnetic induction to change the voltage and current levels in an AC circuit.
Correct answer: Both current and voltage- A. Low, parallel
- B. Low, series
- C. High, parallel
- D. High, series
Explanation: To convert a galvanometer into a voltmeter, it needs to be connected with a resistor having high resistance in series.
Correct answer: High, series- A. Strong
- B. Zero
- C. Weak
- D. None of these
Explanation: The Earth's magnetic field is relatively weak when compared to common magnets such as bar magnets.
Correct answer: Weak- A. 10-7T.m.A-1
- B. 2πx10-7T.m.A-1
- C. 4πx10-7T.m.A-1
- D. 4πx107T.m.A-1
Explanation: The value of the permeability of free space, often denoted as μ₀ (mu naught), is approximately 4π × 10^(-7) T·m/A.The permeability of free…
Correct answer: 4πx10-7T.m.A-1- A. Electric field strength
- B. Resistivity
- C. Magnetic flux density
- D. Inductance
Explanation: The SI unit of magnetic flux density or magnetic field strength is Tesla (T).
Correct answer: Magnetic flux density- A. Straight
- B. In closed loops
- C. In open loops
- D. All of these
Explanation: Eddy currents are loops of electrical current induced within conductors by a changing magnetic field in the conductor, due to Faraday's…
Correct answer: In closed loops- A. F and I
- B. F and L
- C. L and B
- D. I and L
Explanation: The formula F = ILB sin θ describes the magnetic force on a current-carrying conductor in a uniform magnetic field.
Correct answer: L and B- A. Fleming's right-hand rule
- B. None of these
- C. Right hand rule
- D. Fleming's left-hand rule
Explanation: Magnetic flux describes the number of magnetic field lines passing through a surface.
Correct answer: None of these- A. Using a permanent magnet
- B. Using an electric current
- C. Using a temporary magnet
- D. Using a permanent magnet or electric current
Explanation: The correct answer is Option D: Using a permanent magnet or electric current.
Correct answer: Using a permanent magnet or electric current- A. 1296 wb
- B. 12.96 wb
- C. 1190 wb
- D. 1426 wb
Explanation: Flux = NBA / BA so Area is pi x r 2 i.e 3.142 x 4 flux = 100 x 3.142 x 4 = 1296 Wb which is closest to option A which is 1296 Wb As it is…
Correct answer: 1296 wb- A. Electric, Mechanical
- B. Mechanical, Electric
- C. Mechanical, Potential
- D. Not enough information
Explanation: An electric generator is a device that converts mechanical energy into electrical energy.
Correct answer: Mechanical, Electric- A. Bue
- B. Bq/u
- C. Bu/q
- D. 0
Explanation: The force acting on a charge moving through a magnetic field is given by the equation F = qVBsinθ, where q is the charge, B is the…
Correct answer: 0- A. Electric field
- B. Magnetic field
- C. Number of turns
- D. None of these
Explanation: In a step-down transformer, the primary coil has more turns than the secondary coil.
Correct answer: Number of turns- A. Voltage level
- B. Current level
- C. Power level
- D. Frequency level
Explanation: A real transformer does not change the frequency level of the electrical signal passing through it.
Correct answer: Frequency level- A. Strong
- B. Infinite
- C. Negligible
- D. None of these
Explanation: The magnetic field lines in a solenoid are mainly concentrated inside its coils, creating a strong and uniform magnetic field there.
Correct answer: Negligible