Magnetism And Electromagnetism MCQ Questions & Answers

1

Which of the following is a vector quantity?

A) Relative permeability B) Magnetic field intensity C) Flux density D) Magnetic potential

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Answer & Solution

Answer: Option B

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2

What is the magneto-motive force (mmf) of a wire with 8 turns carrying three amperes of current?

A) 2,400 At B) 240 At C) 24 At D) 2.4 At

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Answer & Solution

Answer: Option C

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3

Magnetism of a magnet can be destroyed by

A) heating B) hammering C) by inductive action of another magnet D) by all above methods

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Answer & Solution

Answer: Option D

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4

Strength of an electromagnet can be increased by

A) increasing the cross-sectional area B) increasing the number of turns C) increasing current supply D) all above methods

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Answer & Solution

Answer: Option D

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5

What is the magneto-motive force in a 75-turn coil of wire when there are 4 A of current through it?

A) 18.75 At B) 30 At C) 300 At D) 187 At

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Answer & Solution

Answer: Option C

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6

A magnetic field exists around

A) iron B) copper C) aluminium D) moving charges

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Answer & Solution

Answer: Option D

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7

What will be the magnetic potential difference across the air gap of 2 cm length in magnetic field of 200 AT/m?

A) 2 AT B) 4 AT C) 6 AT D) 10 AT

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Answer & Solution

Answer: Option B

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8

When an iron piece is placed in a magnetic field

A) the magnetic lines of force will bend away from their usual paths in order to go away from the piece B) the magnetic lines of force will bend away from their usual paths in order to pass through the piece C) the magnetic field will not be affected D) the iron piece will break

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Answer & Solution

Answer: Option B

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9

Temporary magnets are used in

A) loud-speakers B) generators C) motors D) all of the above

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Answer & Solution

Answer: Option D

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10

One maxwell is equal to

A) 10^-8 webers B) 10^-4 webers C) 10⁸ webers D) 10⁴ webers

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Answer & Solution

Answer: Option A

Solution:

Explanation:
Maxwell is a unit of magnetic flux in the CGS (centimeter-gram-second) system of units.

1 maxwell is equivalent to 10^-8 webers in the SI (International System of Units).

Reason:
The relation between the CGS and SI units of magnetic flux is established as:
1 weber = 10⁸ maxwells
Hence, 1 maxwell = 10^-8 webers.

Magnetism And Electromagnetism MCQ Questions & Answers | Electrical Engineering