Give reasons :
We are able to see the image of the moon in water .

Give scientific reasons: Why does obtaining the image of the sun on a paper with the help of a concave mirror burn the paper?

Give reasons : A piece of wood sinks more in kerosene than in water .

Give scientific reasons: We need to keep the PIN number of the debit card secret.

Give reasons : It is essential to change the tension on the vocal cords, as we produce different sound notes from our larynx.

Emma is observing an image of a pencil through a convex lens, if she wants to see the erect image of the pencil she should place the pencil

Give reasons: Our mass is same on both the moon and the earth.

Give reason: We must avoid using tissue paper.

Questions based on paragraph : Study the following incident : Swara and yash were looking in a water filled vessel . They could see their images clearly in the still water . At that instant , yash threw a stone in the water . Now their images were blurred . swara could not understand the reason for the blurring of the images . : explain the reason for blurring of the images to swara by answering the following questions : Is there a relation between the reflection of light and the blurring of the images ?