Question 18N.1.HL.TZ0.27

The graph shows the variation with diffraction angle of the intensity of light when monochromatic light is incident on four slits.

The number of slits is increased keeping the width and the separation of the slits unchanged.

Three possible changes to the pattern are

I.   the separation of the primary maxima increases

II.  the intensity of the primary maxima increases

III. the width of the primary maxima decreases.

Which of the possible changes are correct?

A.   I and II only

B.   I and III only

C.   II and III only

D.   I, II and III