List of top Physics Questions on Optical Instruments asked in CBSE CLASS XII

A telescope has an objective lens of focal length 144 cm and an eyepiece of focal length 6·0 cm. The magnifying power and the length of telescope tube will be respectively :

Draw a labelled ray diagram of a refracting telescope when it forms image of a distant object at infinity. Derive the expression for its magnifying power.

In a telescope the objective has much larger aperture than the eyepiece. Why?

Write two advantages of reflecting telescope over refracting telescope.

Draw the ray diagram to show the image formation by a refracting telescope and write the expression for angular magnification for the telescope in normal adjustment.

Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.

Draw a labelled ray diagram of a refracting telescope when it forms image of a distant object at infinity. Derive the expression for its magnifying power.

In a telescope the objective has much larger aperture than the eyepiece. Why?

Write two advantages of reflecting telescope over refracting telescope.

Draw the ray diagram to show the image formation by a refracting telescope and write the expression for angular magnification for the telescope in normal adjustment.

Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.

In normal adjustment, for a refracting telescope, the distance between the objective and eyepiece lens is 1.00 m. If the magnifying power of the telescope is 19, find the focal length of the objective and the eyepiece lens.