Pick the wrong statement in the context with a rainbow.

1. Rainbow is a combined effect of dispersion, refraction, and reflection of sunlight.

2. When the light rays undergo two internal reflections in a water drop, a secondary rainbow is formed.

3.  The order of colours is reversed in the secondary rainbow.

4. An observer can see a rainbow when his front is towards the sun.

A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source L. When the mirror is rotated through a small angle $\theta$, the spot of the light is found to move through a distance y on the scale. The angle $\theta$ is given by:

1. $\frac{y}{x}$

2. $\frac{x}{2y}$

3. $\frac{x}{y}$

4. $\frac{y}{2x}$

A tall man, of height 6 feet, wants to see his full image. The required minimum length of the mirror will be:

1. 12 feet

2. 3 feet

3. 6 feet

4. Any length