In traffic signals _________ colour light is used to stop vehicles because it has ______wave length. (Hint: scattering of light is inversely proportional to the fourth power of its wavelength)

Correct the mistakes, if any, in the following statements.

i) The magnetic field is a quantity that has magnitude only.

ii) Outside the bar magnet, the magnetic field lines emerge from the South Poleand merge at the North Pole.

The ray diagram shown below is introduced to show how a concave mirror forms theimage of an object.

i) Identify the mistake and draw the correct ray diagram.

ii) Write the justifications for your corrections.

Fill the table with the appropriate words given in bracket.

(Convex mirror, Plano convex, concave mirror, Plane mirror, convex lens, Concavelens)

Write down the names of the specified parts of the human eye.

i) Dark muscular diaphragm that controls the pupil.

ii) The screen where the image is formed by the eye lens.