Light Sound and Heat (Class 5)

What this worksheet covers

This is an eighteen-question practice worksheet on light, shadow, sound and heat for Class 5, written to the pattern of the SOF National Science Olympiad (NSO). It carries 24 marks and is designed to be attempted in 40 minutes, split across three sections — Light, Sound and Heat Basics, Apply and Reason 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, shadow, sound and heat at Class 5 level
• Working accurately against a time limit, as the real paper demands
• Light, Sound and Heat Basics questions in the olympiad format
• Apply and Reason 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. Do not use a calculator.
5. 5Study every diagram and table carefully before answering.

Sample questions from this worksheet

A preview of what's inside Light Sound and Heat (Class 5) — the PDF has the full set, and every question comes with a worked solution like these.

1. 1. Light always travels _______.

   • AIn circles
   • BIn curved paths
   • CIn zig-zags
   • DIn straight linescorrect
   Solution: Light travels in straight lines, which is why you cannot see round a corner and why a beam of sunlight entering a dark room appears as a straight streak. This is also the reason shadows are formed.

2. 2. Assertion (A): During a storm we see the flash of lightning before we hear the thunder.Reason (R): Light travels much faster than sound.Choose the correct option.

   • ABoth A and R are true, and R explains Acorrect
   • BBoth A and R are true, but R does not explain A
   • CA is true but R is false
   • DA is false but R is true
   Solution: Both statements are true. The flash and the thunder are produced at the same instant, but light covers the distance to us almost immediately while sound takes several seconds. The huge difference in speed is exactly the reason for the delay, so R explains A.

3. 3. Consider the following statements.(i) Sound can travel through a vacuum.(ii) A shadow is always of the same colour, whatever the colour of the object.(iii) Shiny, light-coloured surfaces reflect more heat than dull black surfaces.Which of the statements is/are correct?

   • A(i) and (ii) only
   • B(ii) and (iii) onlycorrect
   • C(i) and (iii) only
   • DAll three
   Solution: Statement (i) is false — sound needs a material medium to travel through, so it cannot pass through a vacuum; this is why no sound is heard in outer space. Statement (ii) is true; a shadow is simply a region where light is absent, so it is always dark regardless of the object's colour. Statement (iii) is true, which is why white clothes feel cooler in summer. Hence (ii) and (iii).