Saved Bookmarks
| 1. |
A small telescope has an objective lens of focal length 150 cm and and eye piece of focal length 5 cm. If his telescope is used to view a 100 m high tower 3 km away, find the height of the final image when it is formed 25 cm away from the eye piece. |
|
Answer» Solution :`tan alpha=100/3000=1/30` radian `tan alpha=h/f_0` `1/30=h/150` `h=5 CM` h height of image of tower `m_e=(1+ alpha/f_e)=(1+25/5)=6` `m_e=h'/h` `h'=5 TIMES 6=30 cm` h height of final image |
|