Physics Interview Questions and Answers Pdf - 3

Question: 11

What are the sign conventions for lens?

The object is always placed on the left side of the lens, so that the direction of incident light is always from left to right.

All distances are measured from the optic centre of the lens.

The heights measured downward and perpendicular to the principal axis are taken as negative.

The heights measured upward and perpendicular to the principal axis are positive.

The distances measured from the optic centre against the direction of incident light are negative.

Question: 12

How are rainbows caused?

Sunlight is dispersed by tiny droplets of rain clouds and act as prisms to produce rainbows.

Question: 13

Define the refractive index?

Ratio is the sine of the angle of incidence to the sine of the angle of refraction is a constant. This constant is called Refractive Index of the material of the slab.

Question: 14

Define principal axis?

The line passing through the pole and the centre of curvature is called the principal axis.

Question: 15

What is rectilinear propagation of light?

Light travels in a straight line. This is called the rectilinear propagation of light.