Owen Ryan Ang
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Engineering Quiz on MAGNETISM AND ELECTROMAGNETISM, created by Owen Ryan Ang on 24/01/2020.

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Owen Ryan Ang
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MAGNETISM AND ELECTROMAGNETISM

Question 1 of 28

1

A natural magnet is called

Select one of the following:

  • steel

  • lodestone

  • magnetism

  • soft iron

Explanation

Question 2 of 28

1

A magnet is able to attract

Select one of the following:

  • iron, aluminum and brass

  • iron, cobalt and zinc

  • iron, copper and nickel

  • nickel, cobalt and steel

Explanation

Question 3 of 28

1

Externally, magnetic line of force travels

Select one of the following:

  • south to north

  • north to south

  • negative to positive

  • in both directions

Explanation

Question 4 of 28

1

A material commonly used for shielding or screening magnetism is

Select one of the following:

  • brass

  • aluminum

  • copper

  • soft iron

Explanation

Question 5 of 28

1

The magnetism that remains in a magnet after the magnetizing force has been removed is called

Select one of the following:

  • permeability

  • induction

  • residual

  • saturation

Explanation

Question 6 of 28

1

Iron becomes magnetized by induction when it is

Select one of the following:

  • heated

  • suspended east and west

  • near to one end of a magnet

  • treated with some chemicals

Explanation

Question 7 of 28

1

Magnetic lines of force are called

Select one of the following:

  • hysteresis

  • current

  • flux

  • magnetomotive force

Explanation

Question 8 of 28

1

The force between two magnetic poles varies with distance between them. The variation is

Select one of the following:

  • in direct proportion to the distance

  • in inverse proportion to the distance

  • in direct proportion to the square of the distance

  • in inverse proportion to the square of the distance

Explanation

Question 9 of 28

1

The magnetic potential in a magnetic circuit can be measured in terms of

Select one of the following:

  • farads

  • M.M.F.

  • coulombs

  • none of these

Explanation

Question 10 of 28

1

Permeance is analogous to

Select one of the following:

  • conductance

  • resistance

  • reluctance

  • none of these

Explanation

Question 11 of 28

1

The permeability of a material means

Select one of the following:

  • strength of permanent magnet

  • strength of an electromagnet

  • the magnetization left in the iron after exciting field has been removed

  • the conductivity of a material for magnetic lines of force

Explanation

Question 12 of 28

1

When magnetic flux (Φ) and the area (A) under its influence are known, the magnetic flux density (B) can be given as

Select one of the following:

  • B = ΦA

  • B = Φ/A

  • B = A/Φ

  • B = ΦA2

Explanation

Question 13 of 28

1

The relative permeability μr is given by

Select one of the following:

  • B/μr0H

  • B/H

  • μ0/μ

  • μ0/H

Explanation

Question 14 of 28

1

Relative permeability of a material is given by (K is susceptibility of the material)

Select one of the following:

  • 1 + μ0K

  • 1 + K/μ0

  • 1 + μ0/K

  • μ0H

Explanation

Question 15 of 28

1

The relative permeability of paramagnetic substance is

Select one of the following:

  • slightly less than 1

  • equal to 1

  • slightly greater than 1

  • very much greater than 1

Explanation

Question 16 of 28

1

The value of permeability for the free space is

Select one of the following:

  • 4 x 10^-7 Hm-1

  • 4π x 10^-7 Hm-1

  • 4π x 10^7 Hm-1

  • 1/4π x 10^-7 Hm-1

Explanation

Question 17 of 28

1

The magnetization in any magnetic material appears as a result of

Select one of the following:

  • electrons orbital motion

  • electron spin

  • spin of the nucleus about its axis

  • all of these

Explanation

Question 18 of 28

1

The sum of the magnetic moments in unit volume of the solid is called

Select one of the following:

  • field strength

  • magnetism

  • permeability

  • susceptibility

Explanation

Question 19 of 28

1

Which of the following materials does not have permanent magnetic dipole

Select one of the following:

  • paramagnetic

  • antiferromagnetic

  • diamagnetic

  • ferrimagnetic

Explanation

Question 20 of 28

1

Interaction between the neighboring dipoles is negligible in case of a

Select one of the following:

  • paramagnetic material

  • diamagnetic material

  • antiferromagnetic material

  • ferrimagnetic material

Explanation

Question 21 of 28

1

Each ferromagnetic material has characteristic temperature above which its properties are quite different from those below that temperature. That temperature is called

Select one of the following:

  • transition temperature

  • Faraday's temperature

  • demagnetization temperature

  • Curie' temperature

Explanation

Question 22 of 28

1

The relative permability μ for iron is

Select one of the following:

  • 5000

  • 7000

  • 3000

  • 1000

Explanation

Question 23 of 28

1

Which of the following material is used for making permanent magnets

Select one of the following:

  • carbon steel

  • platinum cobalt

  • Alnico V

  • All of these

Explanation

Question 24 of 28

1

Which of the following has the highest value of relative permeability

Select one of the following:

  • iron

  • supermalloy

  • Mu-metal

  • 4% Si - Fe

Explanation

Question 25 of 28

1

Ferrimagnetic materials generally behave as a

Select one of the following:

  • semiconductor

  • conductor

  • insulator

  • any of A, B, or C

Explanation

Question 26 of 28

1

Transformer cores operating at microwave frequency ranges are generally made up of

Select one of the following:

  • ferrites

  • silicon steel

  • supermalloy

  • alnico V

Explanation

Question 27 of 28

1

The magnetic materials which can be easily magnetized in both directions are known as

Select one of the following:

  • soft magnetic materials

  • hard magnetic materials

  • low hysteresis loss materials

  • high hysteresis loss materials

Explanation

Question 28 of 28

1

Eddy current loss can be minimized by

Select one of the following:

  • decreasing the resistance of magnetic medium

  • increasing the resistance of magnetic medium

  • decreasing the permeability of magnetic medium

  • none of these

Explanation

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