NCERT Solutions for Class 4th The World Around Us Chapter 10 The Shadows — Find out
Book page 156 Updated on2026-09-19
Q1.
Take a torch and a stick. Close the doors and windows to make the room dark. Hold the stick in one place and turn on the torch. Shine the torchlight on the stick. Observe the changes in the shadow of the stick, in the following situations: (a) Move the stick back and forth. (b) Change the direction of the torch.
Answer
What you need: a torch, a straight stick or a pencil, and a dark room with a plain wall.
Shut the doors and windows so that the room is dark.
Stand the stick up, or ask a friend to hold it still about one metre from the wall.
Switch on the torch and shine it on the stick. A dark shadow of the stick appears on the wall.
(a) Keep the torch still and move the stick towards the torch, then away from it. Watch the shadow each time.
(b) Keep the stick still and move the torch — to the left, to the right, higher, lower. Watch the shadow each time.
What you will see:
Stick nearer the torch → the shadow becomes bigger. Stick further from the torch → the shadow becomes smaller.
Torch moved to the left → the shadow swings to the right, and the other way round.
Sample answer: “When I brought the pencil close to the torch, its shadow grew till it covered half the wall. When I moved the torch to my left, the shadow slid to the right side of the wall.”
The same stick, the same wall, only the torch is moved.
Why it happens: The shadow is the dark space behind the object where the light cannot reach. Bring the object near the light and it blocks more light, so the dark space is bigger. Move the light to a new side and the dark space moves to the opposite side.
Tip: This is the same rule as sunlight — only here you are moving the light, while outside it is the Sun that appears to move.
Q2.
If we change the distance of the source of light from the stick (an object), how will the shadow change?
Answer
The size of the shadow changes.
If the object is close to the source of light, the shadow is bigger.
If the object is far from the source of light, the shadow is smaller.
The same stick, the same wall, only the torch is moved.
Why it happens: Light spreads out as it travels. An object held close to the torch stands in the narrow part of the light and blocks a large share of it, so it throws a big shadow. The same object held far away blocks only a small share, so the shadow shrinks.
Check it yourself: Hold your hand close to a lamp and look at the wall — a huge hand. Step back and the hand becomes small again.
Q3.
If we change the direction of the torch (source of light), how will the shadow change?
Answer
The direction of the shadow changes.
Shine the torch from the left → the shadow falls to the right.
Shine the torch from the right → the shadow falls to the left.
Hold the torch high above → the shadow becomes short and lies just below the stick.
The rule in one line: the shadow always falls on the side away from the light.
Why it happens: Light travels in straight lines. The stick stops that light, and the dark space is left straight behind the stick. So the moment the light comes from a new side, “behind the stick” means a new side too.
Q4.
We observe that shadows in the morning and evening form in different directions. Why does this happen?
Answer
Because the Sun is on a different side of the sky at those two times.
In the morning the Sun appears in the East. The shadow falls away from it, towards the West.
In the evening the Sun has moved to the West. Now the shadow falls the other way, towards the East.
That is why the evening shadow points exactly opposite to the morning shadow.
Why it happens: It is the same rule you just tested with the torch. Change the direction of the light and you change the direction of the shadow. Outside, the Sun is the torch, and it appears to move from the East to the West through the day.