Question 11

Shown is an apparatus for studying the properties of electrons. Electrons from an emitter F pass through a hole in G and then move into a region where crossed electric (L) and magnetic (M) fields are applied. The spacing between the electric field plates at L is 1 mm. Various target materials can be placed at W. The electrons are detected at a phosphor coated screen labeled x-y. One scale unit on the screen equals 1 cm.

Suppose the crossed electric and magnetic fields are not present so that the electron beam hits point (0,0) on the screen.

If the accelerating voltage between F and G were decreased by a factor of 4, to 50 Volts, then the spot pattern on the screen, from question 10 as shown above, would

A. shrink in scale by a factor of 4
B. shrink by a factor of 2
C. remain unchanged
D. expand by a factor of 2
E. expand by a factor of 4
F. None of the above

Answer

Formula Sheets
Question 10 ... Question 12 ... Up to Unit 18 Table of Contents