What is meant by focal plane of a lens ?

What is meant by optical centre of a lens?

What is meant by power of a lens ? What is one dioptre ?

What is meant by power of a lens ? Write its Sl unit. A student uses a lens of focal length 40 cm and another of - 20 cm. Write the nature and power of each lens.

What is the meant by power of a lens? How the power of a lens related with focal length?

What is meant by power of a lens? What is its unit?

What is meant by power of a lens? Write its SI unit. A student uses a lens of focal length 40 cm and another of -20 cm . Write the nature and power of each lens.

What is meant by power of a lens? Write its SI unit. A student uses a lens of focal length 40 cm and another of -20 cm. Write the nature and power of each lens.