Magnetism and Electromagnetic Induction MCQs

Question 1

A stationary charge in a magnetic field experiences:

Accepted Answer

no magnetic force

Answer

a large magnetic force

Answer

a force along the field

Answer

a force that makes it rotate

Question 2

For a negative charge, the direction of the force from Fleming's left-hand rule must be:

Accepted Answer

reversed (the second finger points opposite to its motion)

Answer

rotated by 45^circ

Answer

unchanged

Answer

zero

Question 3

The force on the wire is perpendicular to:

Accepted Answer

both the current and the magnetic field

Answer

the current only, parallel to the field

Answer

neither

Answer

the wire's length only, along the field

Question 4

The flux linkage of a coil rotating in a uniform field varies:

Accepted Answer

sinusoidally between +NBA and -NBA

Answer

increases steadily

Answer

is always zero

Answer

stays constant

Question 5

The SI unit of magnetic flux density is:

Accepted Answer

tesla (T)

Answer

weber (Wb)

Answer

henry (H)

Answer

newton (N)

Question 6

A coil of 100 turns has an e.m.f. of 5 V induced. The rate of change of flux per turn is:

Accepted Answer

0.05 Wb/s

Answer

20 Wb/s

Answer

500 Wb/s

Answer

5 Wb/s

Question 7

The force on a 1 m wire carrying 1 A perpendicular to a 1 T field is:

Accepted Answer

1 N

Answer

0 N

Answer

0.5 N

Answer

10 N

Question 8

Ferrofluids are useful in electronics because they:

Accepted Answer

can be held in place and moved by magnetic fields

Answer

conduct heat poorly

Answer

emit light

Answer

are solid

Question 9

The factors affecting the size of the induced e.m.f. include:

Accepted Answer

speed of motion, strength of magnet and number of turns

Answer

the room temperature only

Answer

the galvanometer's size

Answer

colour of the wire

Question 10

A mass spectrometer separates ions by mass because ions of the same speed and charge but different mass:

Accepted Answer

move in circles of different radii

Answer

stop at different places

Answer

move in straight lines

Answer

have different charges

Question 11

A ferrofluid is:

Accepted Answer

a liquid containing tiny suspended particles of a magnetic material

Answer

a molten iron metal

Answer

a liquid that conducts electricity like copper

Answer

a gas that is magnetic

Question 12

A coil of area 0.05 m^2 is turned from perpendicular to parallel in a 0.4 T field. The change in flux is:

Accepted Answer

0.02 Wb

Answer

0.04 Wb

Answer

8 Wb

Answer

0 Wb

Question 13

The magnetic force on a moving charge is always:

Accepted Answer

perpendicular to its velocity

Answer

parallel to its velocity

Answer

along the field

Answer

zero

Question 14

A coil of area 0.04 m^2 is in a 0.5 T field; the field makes 60^circ with the normal to the coil. The flux through the coil is:

Accepted Answer

0.01 Wb

Answer

0.1 Wb

Answer

0.02 Wb

Answer

0.005 Wb

Question 15

The flux through a coil is maximum when the plane of the coil is:

Accepted Answer

perpendicular to the field

Answer

at 45^circ

Answer

at 30^circ

Answer

parallel to the field

Question 16

Charged particles from the Sun spiral along the Earth's field lines towards the poles, causing:

Accepted Answer

the aurora (northern and southern lights)

Answer

rainbows

Answer

earthquakes

Answer

lightning

Question 17

A particle faster than E/B entering a velocity selector is deflected:

Accepted Answer

in the direction of the magnetic force

Answer

backwards

Answer

not at all

Answer

in the direction of the electric force

Question 18

In a simple seismometer, the coil is:

Accepted Answer

suspended by a spring from the frame

Answer

fixed rigidly to the ground

Answer

made of plastic

Answer

inside the magnet

Question 19

A magnetic field is a region where:

Accepted Answer

a magnetic material, magnet or moving charge experiences a force

Answer

nothing happens

Answer

only masses experience a force

Answer

a stationary charge experiences a force

Question 20

The particles in a ferrofluid are very small, about:

Accepted Answer

10 nanometres

Answer

1 millimetre

Answer

1 centimetre

Answer

1 metre

Question 21

An electron moves at 1 10^7 m/s perpendicular to a 0.01 T field. The radius of its circular path is (m = 9.11 10^-31 kg, q = 1.6 10^-19 C):

Accepted Answer

0.00569 m

Answer

0.0114 m

Answer

5.69 10^-4 m

Answer

0.0569 m

Question 22

Magnetic flux density is also called:

Accepted Answer

magnetic field strength (in many textbooks)

Answer

permeability

Answer

magnetic flux

Answer

flux linkage

Question 23

A current-carrying conductor placed in a magnetic field:

Accepted Answer

may experience a force

Answer

always melts

Answer

loses its current

Answer

never experiences a force

Question 24

Ferrofluid spikes are an example of:

Accepted Answer

a balance between magnetic forces, gravity and surface tension

Answer

chemical reaction

Answer

electrical breakdown

Answer

nuclear decay

Question 25

1 T = 1 Wb m^-2 shows that flux density is:

Accepted Answer

flux per unit area

Answer

area per unit flux

Answer

flux times area

Answer

force per charge

Magnetism and Electromagnetic Induction MCQs — Physics

1. A stationary charge in a magnetic field experiences:

2. For a negative charge, the direction of the force from Fleming's left-hand rule must be:

3. The force on the wire is perpendicular to:

4. The flux linkage of a coil rotating in a uniform field varies:

5. The SI unit of magnetic flux density is:

6. A coil of 100 turns has an e.m.f. of 5 V induced. The rate of change of flux per turn is:

7. The force on a 1 m wire carrying 1 A perpendicular to a 1 T field is:

8. Ferrofluids are useful in electronics because they:

9. The factors affecting the size of the induced e.m.f. include:

10. A mass spectrometer separates ions by mass because ions of the same speed and charge but different mass:

11. A ferrofluid is:

12. A coil of area 0.05 m^2 is turned from perpendicular to parallel in a 0.4 T field. The change in flux is:

13. The magnetic force on a moving charge is always:

14. A coil of area 0.04 m^2 is in a 0.5 T field; the field makes 60^circ with the normal to the coil. The flux through the coil is:

15. The flux through a coil is maximum when the plane of the coil is:

16. Charged particles from the Sun spiral along the Earth's field lines towards the poles, causing:

17. A particle faster than E/B entering a velocity selector is deflected:

18. In a simple seismometer, the coil is:

19. A magnetic field is a region where:

20. The particles in a ferrofluid are very small, about:

21. An electron moves at 1 10^7 m/s perpendicular to a 0.01 T field. The radius of its circular path is (m = 9.11 10^-31 kg, q = 1.6 10^-19 C):

22. Magnetic flux density is also called:

23. A current-carrying conductor placed in a magnetic field:

24. Ferrofluid spikes are an example of:

25. 1 T = 1 Wb m^-2 shows that flux density is:

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