Correct the following sentences if required:
The power of a lens is numerically equal to its focal length.

Correct the following sentences if required: Transparent bodies such as glass are visible due to partial reflection from its surface.

If the lens is double concave then its focal length is

Correct the following sentences if required: The focal length of a concave mirror changes when immersed in water.

State whether the following statements are True (T) or False (F): The power of a lens is 4D. The focal length is 50 cm.

Write Yes or No. The power of a lens is (+1) Diopter. Its focal length is (+1) meter.