Start by opening the site

1. The first right hand rule is for a current going through a wire.

a. Open the first applet - (if it works) move the current from + to -

Sketch a wire with a current and show the direction of the field around the wire

b. How does changeing the direction of the current affect the direction of the field.

Note that if you were to hold the wire **with your right hand **so your thumb points in the direction of the current - your fingers curl in the direction of the field

2. The second right hand rule is for charges moving through a magnetic field

a. Open the second applet - use the right hand rule to verify that the magnetic field is going in to the screen. Draw a sketch showing the positive charge, the direction of the

magnetic field and the direction of the force on the charge at any point.

b. Explain - why does the charge move in a circle?

c. How does each of the following affect the motion of the charge?

i. increasing the charge

ii. increasing the velocity

iii. increasing the magnetic field

d. So after all the it is evident that the force is affected by the magnitude of the charge, the strength of the field and the velocity of the charge (at a right angle to the field).

and the equation is:

F = qvB

as you will recall : F = ma

Use these two equations setting ma = qvB to make an equation:

a = _______ in terms of q, v, B and m

(option - skip tho part f)

e. According to your equation, how do each of these things affect the acceleration, a?

- increasing m

- increasing B

- increasing q

increasing v

f. Now for an object in circular motion - acceleration is related to the radius of the circle. It is called centripital acceleration.

a = v^{2}/r

rerwrite the equation for a using the centripital acceleration and put it in the form:

r = __________

How do each of the items in part e affect the radius of the circle according to your equation. Verify this with the applet.