Free Magnetic Flux Density MCQs with Answers
96 Magnetic Flux Density 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 measures the magnetic force acting on a current carrying conductor or moving charge in a magnetic field. Work includes the relations B equals F divided by IL and F equals qvB, the tesla as its SI unit, field direction and the distinction between flux density and magnetic flux.
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- A. F=1/B
- B. F=1/Bsinθ
- C. F/0
- D. F=1/Bcosθ
Explanation: The magnetic force on a current-carrying conductor is F = BIL sinθ. When the conductor is parallel to the field, θ = 0° and sin0° = 0, so…
Correct answer: F/0- A. be rotating
- B. come to rest in N-S direction
- C. vibrating like galvanometer needle
- D. comes to rest after rotation
Explanation: A current-carrying solenoid behaves like a bar magnet, so its magnetic dipole aligns itself with Earth's magnetic field when freely…
Correct answer: come to rest in N-S direction- A. BINA cosa
- B. BINA sina
- C. BINA tana
- D. BINA
Explanation: The deflecting torque on a current-carrying coil is τ = BINA sin α. In a radial magnetic field, the field is always effectively…
Correct answer: BINA- A. NA-1m-1
- B. NAm-1
- C. NmA-1
- D. NmA-2
Explanation: Magnetic flux density has the SI unit tesla, and 1 T = 1 N A^-1 m^-1. Students may choose d, N m A^-2, because it is dimensionally…
Correct answer: NA-1m-1- A. 1T = 103 G
- B. 1T = 10-4 G
- C. 1T = 10-2 G
- D. 1T = 104 G
Explanation: The conversion is 1 tesla = 10,000 gauss = 10^4 G, so option d is correct.
Correct answer: 1T = 104 G- A. air
- B. steel
- C. Cu-Ni alloy
- D. soft iron
Explanation: Soft iron is suitable for an electromagnet because it has high magnetic permeability and loses most of its magnetism when the current is…
Correct answer: soft iron- A. repel each other
- B. attract each other
- C. have no effect upon each other
- D. they cancel out their individual magnetic fields
Explanation: Parallel currents in the same direction attract, while parallel currents in opposite directions repel because of the magnetic force…
Correct answer: repel each other- A. 1A
- B. 10A
- C. 100A
- D. 1000A
Explanation: For a wire perpendicular to the field, F = BIL. Thus I = F/(BL) = 5 N / [(0.5 T)(0.10 m)] = 5 N / 0.05 T m = 100 A, since 1 T m A = 1 N.
Correct answer: 100A- A. magnetic flux
- B. magnetic field intensity
- C. magnetic induction
- D. self inductance
Explanation: From F = qvB for perpendicular motion, B = F/(qv). For a unit positive charge and unit velocity, B equals the magnetic force numerically…
Correct answer: magnetic induction- A. Demagnetization
- B. Breakage
- C. Extension
- D. Surface cracking
Explanation: Coercive force is the reverse magnetic field required to reduce the magnetisation of a magnet to zero, so it opposes demagnetisation.
Correct answer: Demagnetization- A. Semi-conductor becomes conductors
- B. Ferromagnetic becomes paramagnetic
- C. Paramagnetic becomes diamagnetic
- D. Metals become super conductor
Explanation: At the Curie temperature, thermal agitation destroys the long-range alignment of magnetic domains, changing a ferromagnetic material into…
Correct answer: Ferromagnetic becomes paramagnetic- A. Hysteresis curve
- B. Hysteresis loop area
- C. Hysteresis loop
- D. Straight line
Explanation: The area enclosed by a hysteresis loop represents the energy lost per unit volume in one complete magnetisation cycle, so it measures the…
Correct answer: Hysteresis loop area- A. Squids
- B. Magnetic resonance imaging (MRI)
- C. Magnetometer
- D. Oscilloscope
Explanation: SQUIDs, or superconducting quantum interference devices, detect extremely small changes in magnetic flux and are therefore used for very…
Correct answer: Squids- A. High voltage A.C
- B. Low voltage A.C
- C. Alternating current at its peak value
- D. D.C current at peak value
Explanation: For an alternating magnetizing current, the magnetic field reaches its greatest value when the current is at its peak, allowing a…
Correct answer: Alternating current at its peak value- A. 0.002 T
- B. 2.5 x 10^-6 T
- C. 0.005 T
- D. 4 x 10^-6 T
Explanation: The magnetic field at ground due to a current-carrying wire is given by the formula:B = μ₀I/(2πr)where μ₀ is the permeability of free…
Correct answer: 2.5 x 10^-6 T- A. Strength
- B. Flux
- C. Magnetic flux density
- D. Density
Explanation: .Option A) Strength is not correct because it is a general term and does not specifically refer to the strength of a magnetic field.Option…
Correct answer: Magnetic flux density- A. Flux
- B. Magnetization
- C. Magnetic intensity
- D. Flux intensity
Explanation: Correct option is C.The magnetic flux density or magnetic induction is also known is magnetic field strength , B.
Correct answer: Magnetic intensity- A. Flux
- B. Density
- C. Magnetic strength
- D. Magnetic flux density
Explanation: Magnetic field strength is a measure of the intensity of a magnetic field in a given area of that field.
Correct answer: Magnetic flux density- A. four times
- B. two times
- C. three times
- D. six times
Explanation: Option A is correct since magnetic energy density is proportional to the square of the magnetic field as shown in the image : Therefore…
Correct answer: four times- A. Not intersecting
- B. Intersect near south pole
- C. Intersect near north pole
- D. Intersect everywhere
Explanation: If magnetic field lines intersect each other, then at the intersection point there will be two directions of the same field which is not…
Correct answer: Not intersecting