An electron moving perpendicular to a magnetic field of 2.2 10-2 T moves in a circle of certain radius. If the electron is moving with a speed of 1.5 107 m/s, what is the radius of the circle?
A)
1.5 10-3 m
B)
2.2 10-4 m
C)
2.2 10-3 m
D)
3.9 10-4 m
E)
3.9 10-3 m
Question 2
The output of a generator is 440 V at 20 A. It is to be transmitted on a line with resistance of 0.60 .
To what voltage must the generator output be stepped up with a transformer if the power loss in transmission is not to exceed 0.010 of the original power?
A)
4.4 kV
B)
7.3 kV
C)
22 kV
D)
30 kW
E)
45 kV