1 A velocity selector uses a 60 mT magnetic field perpendicu

1. A velocity selector uses a 60 mT magnetic field perpendicular to a 24 kN/C electric field.
Part A
At what speed will charged particles pass through the selector undeflected?
v=m/s
2. How long does it take an electron to complete a circular orbit perpendicular to a 1.1 G magnetic field?
Express your answer using two significant figures.
T= ns
3. Radio astronomers detect electromagnetic radiation at a frequency of 42 MHz from an interstellar gas cloud
Part A
If this radiation is caused by electrons spiraling in a magnetic field, what is the field strength?
Express your answer using two significant figures.
B= T

Solution

1. v = E/B = 24000/(60*10^-3) = 4*10^5 m/sec

2. T = 2*pi*m/qB = 2*3.14*9.1*10^-31/(1.6*10^-9*1.1*10^4)

T = 324.7 ns

3. B = 2*pi*m/qT

1/T = f

B = 2*3.14*42*10^6*9.1*10^-31/(1.6*10^-19) = 1.5*10^-3 T

Let me knowif you have any doubt.