The objective of a telescope has focal length

PHYSICS · Single correct · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments

Problem

150\,\text{cm}

. What should be the focal length of the eyepiece so that the telescope provides a magnifying power of

30

(final image at infinity)? (a)

6.3\,\text{cm}

(b)

5\,\text{cm}

(c)

0.2\,\text{cm}

(d)

25\,\text{cm}