Question

Changes or phases in appearance of moon are caused by movement of moon around the:

• A. Sun
• B. Earth
• C. Planets
• D. All of these

Answer 1

Answer: (B)

Earth

For practical understanding, you can perform the experiment given below

Take a torch, switch it on and place it on a table.

Stand in front of the source of light of the torch.

Take a small ball and hold it at a height same as that of the torch and facing the torch.

You will notice that the ball appears dark.

Now if you change the position of the ball, keeping the height same, you will notice that only some part of the ball appears illuminated.

If you place it diametrically opposite to the torch, but at height slightly higher than your head, the entire ball gets illuminated.

You can also notice that when the ball appears completely dark, the ball is closest to the torch.

The phases of the moon are due to situations similar to this experiment.

In this experiment, you represent the earth, the torch represents the sun and the ball the moon.

You can see that the changes in appearance of the ball are caused by movement of the ball around you.