Question

A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength $20 \, Vm^{-1}$ and 0.5 T at right angles to the direction of motion of the electrons. What is the velocity of the electrons?

• A. 20 $ms^{-1}$
• B. 40 $ms^{-1}$
• C. 8 $ms^{-1}$
• D. 5.5 $ms^{-1}$

Answer 1

Answer: (A)

20 $ms^{-1}$

Answer 2

Answer (a) 20 $ms^{-1}$