Question

1. Answer all parts for the theory.

a. The magnetic field B acting upon a charge q moving at velocity v gives rise to a

force in direction perpendicular to ____________________.

1. The velocity v

2. The magnetic field B and the charge q

3. The magnetic field B

4. The velocity v and the magnetic field B

b. Having a beam of electrons moving horizontally to the right side of the paper,

what is the direction of the magnetic force if we applied a magnetic field going

I. into the paper.

II. out of the paper.

c. If we connected the solenoid to an AC current and then measured the magnetic

field inside of it. What do you expect to see on the gaussmeter’s screen?

d. Pair production is a physical process where a photon (light particle) creates an

electron and a positron, the anti-electron, under the right conditions. We know that both

particles have the same mass but opposite electric charges. If you were asked to

differentiate between them in the frame of today’s lab, how would you do so?

Answer 1

1.)

(a.) The velocity v and the magnetic field B.

(b.)

I.) Direction of magnetic force will be towards downwards of page horizontally.

II.) Direction of magnetic force will be towards upwards of page horizontally.

(c.) Since the solenoid is connected to an AC cureent, the direction of current will keep alternating. Hence, Direction of the magnetic field will also keep changing directions. So, the needle of the gaussmeter will keep oscillating.

(d.) We will apply an electric field and note the direction of motion (acceleration) of the two particles. The one which moves in the direction of the electric field will pe positron, whereas the one which will move in the direction opposite to the direction of the electric field will be electron.