Question 1

Which of the following substances enables us to see objects?

Accepted Answer

Light is the form of energy that enables us to see objects. When light falls on an object, it gets reflected and enters our eyes, allowing us to perceive the object.

Question 2

What is the angle of reflection if the angle of incidence is 45 degrees?

Accepted Answer

According to the first law of reflection, the angle of incidence is always equal to the angle of reflection. Therefore, if the angle of incidence is 45 degrees, the angle of reflection will also be 45 degrees.

Question 3

An incident ray makes an angle of 30 degrees with the reflecting surface. What is the angle of incidence?

Accepted Answer

The angle of incidence is the angle between the incident ray and the normal drawn at the point of incidence. Since the normal is perpendicular (90 degrees) to the surface, the angle of incidence is 90 - 30 = 60 degrees.

Question 4

Which type of reflection takes place from a smooth and polished surface like a plane mirror?

Accepted Answer

Regular reflection (also called specular reflection) takes place from smooth and polished surfaces like plane mirrors, where parallel rays of light remain parallel after reflection.

Question 5

Diffused reflection occurs from which of the following surfaces?

Accepted Answer

Diffused reflection occurs from rough or irregular surfaces like cardboard, walls, or unpolished wood, because the irregularities on the surface reflect light in different directions.

Light — CBSE Class 8 Science Important Questions & Revision Notes