What do you mean by power of lens ?

What do you mean by power of a lens ? What is the SI unit of the power of a lens ? Calculate the power of a concave lens of focal length 25 cm.

Combination of lenses are used in optical instruments to obtain the required power. What do you mean by power of a lens ? Express its unit.

What do you mean by power of an agent ? Give an expression for power.

Answer the following questions : What do you mean by Power of A test?

What do you mean by power of accommodation?

What do you mean by power of accommodation?