(a)[1]
Explain what is meant by interference.
(b(i))[2]
A ripple tank is used to show interference between water waves. Describe the apparatus used to create two sources of coherent waves with circular wavefronts.
(b(ii))[2]
Describe how the pattern formed by the interfering waves can be observed.
(c(i))[1]
A wave pattern produced in (b) is shown in Fig. 7.1. The solid lines in Fig. 7.1 show crests. On Fig. 7.1, draw two lines to indicate where maxima would be observed (label each line X).
(c(ii))[1]
Draw one line to show where minima would be observed (label the line $N$).