6 7 The diagram shows the position of two particles, X and Y, on a transverse wave. The wave is travelling from left to right. direction of wave travel Y X Which of the following describes the directions in which the particles at X and Y are moving at the instant shown? Particle X Particle Y A down down B down up C up down D up up (Total for Question 7 = 1 mark) 8 A beam of light from a torch with power P is shone onto a surface. The light is spread over a circular area with a radius r. Which of the following gives the intensity of the light on the surface? A P × 4πr2 B 2 4π P r C P × πr2 D 2 π P r (Total for Question 8 = 1 mark)