Light Natural Phenomena and Pollution (Class 8)

What this worksheet covers

This is an eighteen-question practice worksheet on light, natural phenomena and pollution for Class 8, written to the pattern of the SOF National Science Olympiad (NSO). It carries 24 marks and is designed to be attempted in 45 minutes, split across three sections — Scientific Reasoning, Applying What You Know and Achievers Section. Every question is multiple choice with exactly one correct option, and every one comes with a fully worked solution rather than just an answer key — so a child who gets one wrong can see where the reasoning went astray instead of only learning that it did.

Skills your child practises

• Applied problem-solving on light, natural phenomena and pollution at Class 8 level
• Working accurately against a time limit, as the real paper demands
• Scientific Reasoning questions in the olympiad format
• Applying What You Know questions in the olympiad format
• Achievers Section questions in the olympiad format
• Reading worked solutions to find the step that went wrong

How to use it

1. 1There are 18 questions in this worksheet. All questions are compulsory.
2. 2Each question has four options (A), (B), (C) and (D). Exactly one option is correct.
3. 3Questions 1–15 carry 1 mark each. Questions 16–18 (Achievers Section) carry 3 marks each.
4. 4There is no negative marking. Study every diagram and table carefully.

Sample questions from this worksheet

A preview of what's inside Light Natural Phenomena and Pollution (Class 8) — the PDF has the full set, and every question comes with a worked solution like these.

1. 1. According to the laws of reflection, the angle of incidence is _______ the angle of reflection.

   • AEqual tocorrect
   • BLess than
   • CGreater than
   • DTwice
   Solution: The first law of reflection states that the angle of incidence is equal to the angle of reflection. The second states that the incident ray, the reflected ray and the normal all lie in the same plane.

2. 2. A ray of light strikes a plane mirror at an angle of incidence of 35°. What is the angle between the incident ray and the reflected ray?

   • A35°
   • B55°
   • C70°correct
   • D110°
   Solution: The angle of reflection also equals 35°, and both are measured from the normal.
   Angle between the two rays = 35° + 35° = 70°.

3. 3. Two plane mirrors are placed at right angles to each other and an object is placed between them. How many images are formed?

   • A3correct
   • B2
   • C1
   • DInfinitely many
   Solution: The number of images formed by two mirrors at an angle θ is (360 ÷ θ) − 1.
   Here θ = 90°, so the number of images = (360 ÷ 90) − 1 = 4 − 1 = 3.
   (If the mirrors were parallel, θ would be 0 and infinitely many images would form.)