This question is about the velocity selector shown in Figure 25.11. a. State the directions of the

Question:

This question is about the velocity selector shown in Figure 25.11.

a. State the directions of the magnetic and electric forces on a positively charged ion travelling towards the slit S.
b. Calculate the speed of an ion emerging from the slit S when the magnetic flux density is 0.30 T and the electric field strength is 1.5 × 10³ V m⁻¹.
c. Explain why ions travelling with a speed greater than your answer to part b will not emerge from the slit.