Exam 2

Question 1

The force on a charged particle created by its motion in a magnetic field is maximum at what angle between the particle velocity and field?

Answer 1

90 degrees

Question 2

A proton moves across Earth’s equator in a northeasterly direction. At this point the Earth’s magnetic field has a direction due north and is parallel to the surface. What is the direction of the force acting on the proton at this instant?

Answer 2

Out of the Earth’s surface

Question 3

If a proton is released at the equator and falls toward the earth under the influence of gravity, the magnetic force on the proton will be

Answer 3

East

Question 4

A horizontal wire of length 3.0 m carries a current of 6.0A and is oriented so that the current direction is 50 degrees Sof W. The earth’s magnetic field is due north at this point and has a strength of .14 E-4. What is the direction of the force on the wire?

Answer 4

Toward Earth’s surface

Question 5

A metal rod is falling toward the surface of the earth near the equator. As it falls, one end of the rod becomes positively charged due to motional emf of the rod through the Earth’s magnetic field. The rod is oriented so that:

Answer 5

The rod is horizontal with positive end toward the east.

Question 6

Two loops of wire are arranged so that a changing current in one will induce current in the other. If the current in the first is increasing clockwise by 1.0 A every second, the induced current on the second loop will

Answer 6

stay constant.

Question 7

Basic function of electric generator is which of the following conversion processes?

Answer 7

Mechanical energy to electrical

Question 8

Basic function of electric motor is which of the following conversion processes?

Answer 8

Electrical energy to mechanical

Question 9

In an AC series circuit, the current in a pure resistor differs in phase with the applied voltage by what angle?

Answer 9

Zero

Question 10

In a capacitor in an AC circuit, the voltage

Answer 10

Lags the current by 90 degrees

Question 11

In an AC series circuit the voltage in the inductor differs in phase with the voltage in the capacitor by what angle?

Answer 11

180 degrees

Question 12

The current in an inductor connected to an AC voltage source lags voltage. This lag is caused by the

Answer 12

voltage across the coil

Question 13

The wave particle duality of light means in the same experiment

Answer 13

Light will not act like either a wave or a particle

Question 14

When you view your image in a hand held mirror, if you move the mirror away at a speed v, the image appears to

Answer 14

move away at 2v

Question 15

As a monochromatic light ray is transmitted through an air to glass boundary, what happens to the wavelength?

Answer 15

Decreases

Question 16

What will happen to a light ray incident on a glass to air boundary at greater than the critical angle?

Answer 16

Total reflection

Question 17

A deuteron with the same charge but twice the mass of a proton moves with speed of 3.0 E 5 perpindicular to a uniform magetic field of .20 T. Which of the paths below would it follow?

Answer 17

Circular path of 3.1 radius

Question 18

Two insulated carrying straight wires of equal length are arranged so A carries current north and B carries current east. The wires cross at midpoint separated only by insulation. Which is true?

Answer 18

There are forces, but the net force on each wire is zero.

Question 19

A bar magnet falls through a loop of wire with constant velocity. North pole enters first. As south pole leaves wire loop, induced current will be

Answer 19

Clockwise

Question 20

Two parallel conductorss are carrying current in opposite direction. Currents are non zero and not necessarily equal. The magnitude of the magnetic field midway between them is 40 microT. If one of the currents has its direction reversed, what is the resulting magnitude of the magnetic field midway between them?

Answer 20

Value greater than 40 micro T

Question 21

In a circuit made up of inductor, resistance, ammeter, battery, and switch in series at which of the following times after the switch is closed is the rate of current increase greatest?

Answer 21

Zero

Question 22

A circular current loop is placed in an external magnetic field. How is the torque related to the radias of the loop?

Answer 22

Directly proportional to radius squared

Question 23

A bar magnet is held above the center of a conducting ring in the horizontal plane. The magnet is dropped so it falls lengthwise toward the center of the ring. Will the falling magnet be attracted toward the ring or be repelled by the ring due to magnetic interaction of the magnet and ring?

Answer 23

It will be repelled