Question

18 . In which of the following materials speed of sound is maximum? ( )



(a) Iron (b) Sea water (c) Fresh water (d) Air



19. Which of the following cannot be charged easily by friction? ( )



(a) A plastic scale (b) An inflated balloon (c) A copper rod (d) A woollen cloth



20. The splitting of white light into its seven constituent colours is called ( )



(a) Dispersion (b) Reflection (c) Refraction (d) Rectilinear propagation

Answer 1

hey mate

here is ur answer

a) iron
b) A copper rod
c) Dispersion.

i hope it helps you

Answer 2

Explanation:hello mate here is your answer(1); Iron