Magnetism and Electromagnetic Induction MCQs

Question 1

A particle slower than E/B is deflected:

Accepted Answer

in the direction of the electric force

Answer

not at all

Answer

in the direction of the magnetic force

Answer

into a circle

Question 2

The flux through each of 1000 turns of a coil changes by 5 10^-4 Wb in 0.25 s. The average induced e.m.f. is:

Accepted Answer

2 V

Answer

1 V

Answer

0.002 V

Answer

4 V

Question 3

The flux through each of 50 turns of a coil changes by 0.002 Wb in 0.01 s. The average induced e.m.f. is:

Accepted Answer

10 V

Answer

5 V

Answer

0.2 V

Answer

20 V

Question 4

A 0.4 m wire carrying 3 A at right angles to a field experiences 0.6 N. The flux density is:

Accepted Answer

0.5 T

Answer

1 T

Answer

0.72 T

Answer

0.25 T

Question 5

The ferrous core is placed:

Accepted Answer

inside the coil, along its axis

Answer

outside the coil, at right angles

Answer

between the turns of wire only

Answer

far from the coil

Question 6

The output of a seismometer is recorded as a:

Accepted Answer

seismogram

Answer

radiograph

Answer

spectrum

Answer

thermogram

Question 7

A proton (charge 1.6 10^-19 C) moves at 40,000 m/s at 0^circ to a field of 0.8 T. The magnetic force on it is:

Accepted Answer

0 N

Answer

2.56 10^-15 N

Answer

5.12 10^-15 N

Answer

6.4 10^-15 N

Question 8

If the plane of a coil is parallel to the magnetic field, the flux through it is:

Accepted Answer

zero

Answer

2BA

Answer

maximum

Answer

BA

Question 9

Faraday's law states that the induced e.m.f. is proportional to:

Accepted Answer

the rate of change of magnetic flux linkage

Answer

the magnet's mass

Answer

the flux linkage itself

Answer

the resistance of the coil

Question 10

A coil of area 0.05 m^2 perpendicular to a 0.4 T field is flipped through 180^circ. The change in flux is:

Accepted Answer

0.04 Wb

Answer

0.08 Wb

Answer

0.02 Wb

Answer

0 Wb

Question 11

If the ground does not move, the induced e.m.f. in a seismometer is:

Accepted Answer

zero

Answer

negative

Answer

constant and large

Answer

maximum

Question 12

A wire carrying current in the same direction as a magnetic field experiences:

Accepted Answer

no force

Answer

a torque

Answer

a force along the wire

Answer

maximum force

Question 13

Looking at one end of a solenoid, the current flows anticlockwise. That end is a:

Accepted Answer

north pole

Answer

point of zero field

Answer

neutral point

Answer

south pole

Question 14

The physical law that explains the seismometer's output is:

Accepted Answer

Faraday's law of electromagnetic induction

Answer

Hooke's law only

Answer

Snell's law

Answer

Boyle's law

Question 15

1 weber equals:

Accepted Answer

1 T m^2

Answer

1 V/s

Answer

1 N/A

Answer

1 T/m^2

Question 16

The ratio q/m of a particle can be found from its circular path using:

Accepted Answer

qm = vBr

Answer

qm = Brv

Answer

qm = Brv

Answer

qm = Brv

Question 17

A particle passes undeflected through a velocity selector when:

Accepted Answer

the electric force equals the magnetic force in size and they act in opposite directions

Answer

the magnetic force is twice the electric force

Answer

it has no charge only

Answer

both forces are zero

Question 18

The force between two current-carrying wires arises because:

Accepted Answer

each wire is in the magnetic field produced by the other

Answer

the wires are hot

Answer

of gravity

Answer

the wires are charged

Question 19

A charged particle moving parallel to a magnetic field:

Accepted Answer

experiences no magnetic force

Answer

is accelerated along the field

Answer

stops

Answer

moves in a circle

Question 20

A proton and an electron move at the same velocity perpendicular to a field. The forces on them are:

Accepted Answer

equal in size and opposite in direction

Answer

zero

Answer

equal in size and direction

Answer

different in size

Question 21

The field inside a long solenoid is:

Accepted Answer

uniform and parallel to its axis

Answer

circular

Answer

radial

Answer

zero

Question 22

Velocity selectors are used in:

Accepted Answer

mass spectrometers

Answer

transformers

Answer

thermometers

Answer

loudspeakers

Question 23

In a velocity selector, E = 12,000 V/m and B = 0.004 T are at right angles. The speed of particles that pass through undeflected is:

Accepted Answer

3 10^6 m/s

Answer

48 m/s

Answer

1.5 10^6 m/s

Answer

6 10^6 m/s

Question 24

Which arrangement gives the most uniform magnetic field?

Accepted Answer

the inside of a long solenoid

Answer

near a flat coil's edge

Answer

near a straight wire

Answer

near a bar magnet's pole

Question 25

Moving the magnet faster into the coil makes the deflection:

Accepted Answer

larger

Answer

smaller

Answer

reversed

Answer

zero

Magnetism and Electromagnetic Induction MCQs — Physics (page 8)

176. A particle slower than E/B is deflected:

177. The flux through each of 1000 turns of a coil changes by 5 10^-4 Wb in 0.25 s. The average induced e.m.f. is:

178. The flux through each of 50 turns of a coil changes by 0.002 Wb in 0.01 s. The average induced e.m.f. is:

179. A 0.4 m wire carrying 3 A at right angles to a field experiences 0.6 N. The flux density is:

180. The ferrous core is placed:

181. The output of a seismometer is recorded as a:

182. A proton (charge 1.6 10^-19 C) moves at 40,000 m/s at 0^circ to a field of 0.8 T. The magnetic force on it is:

183. If the plane of a coil is parallel to the magnetic field, the flux through it is:

184. Faraday's law states that the induced e.m.f. is proportional to:

185. A coil of area 0.05 m^2 perpendicular to a 0.4 T field is flipped through 180^circ. The change in flux is:

186. If the ground does not move, the induced e.m.f. in a seismometer is:

187. A wire carrying current in the same direction as a magnetic field experiences:

188. Looking at one end of a solenoid, the current flows anticlockwise. That end is a:

189. The physical law that explains the seismometer's output is:

190. 1 weber equals:

191. The ratio q/m of a particle can be found from its circular path using:

192. A particle passes undeflected through a velocity selector when:

193. The force between two current-carrying wires arises because:

194. A charged particle moving parallel to a magnetic field:

195. A proton and an electron move at the same velocity perpendicular to a field. The forces on them are:

196. The field inside a long solenoid is:

197. Velocity selectors are used in:

198. In a velocity selector, E = 12,000 V/m and B = 0.004 T are at right angles. The speed of particles that pass through undeflected is:

199. Which arrangement gives the most uniform magnetic field?

200. Moving the magnet faster into the coil makes the deflection:

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