1. A 12V battery is connected to a parallel plate capacitor

a) A proton escapes from the positive plate and accelerates to the negative plate. How much kinetic energy does it gain?

b) What is the final velocity of the proton?

c) The proton passed through a hole in the negative plate into an area where there is a magnetic field of 2T at right angles to the direction of the protons velocity. What is the radius of the curved path the proton is forced to follow?

2. A back yard inventor is trying to make a 1.0 ohm resistor out of some old bits of wire. There is Nichrome wire of diameter 0.5mm and Tungsten wire of 0.2mm.

a) How long should each piece of wire be to give the required resistance?

b) How much would the resistance of each change if the temperature in the shed the inventor is working in rose from 20oC to 30oC

c) Which do you think would make the best resistor and why?

Resistivity

Nichrome 1.50 x 10^-6 ohm.m

Tungsten 5.6 x 10^-8 ohm.m

Temperature Coefficient

Nichrome 0.4 x 10^-3 oc^-l

Tungsten 4.5 x 10^-3 oc^-1