A tight-rope walker carries a long pole which he holds across his body. The purpose of this pole is to_____.

Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?
I. Diffusion
II. Refraction
III. Internal reflection

Consider the following statements:
I. Light of longer wavelength is scattered much more than the light of shorter wavelength.
II. The speed of visible light in water is $0.95$ times the speed in a vacuum.
III. Radio waves are produced by rapidly oscillating electrical currents.
IV. To detect the over speeding vehicles, police use the Doppler effect of reflected short radio waves.
Which of these statements are correct?

Match the following: