In: Physics
An inquiring student makes a refracting telescope by placing an objective lens and an eyepiece at opposite ends of a 45.0 cm long tube. If the eyepiece has a focal length of 1.70 cm, calculate the required focal length in cm of the objective lens and the angular magnification of the telescope.
HINT
(a)
the required focal length in cm of the objective lens
cm
(b)
the angular magnification of the telescope
Solution::
L= 45.0 cm =eyepiece at opposite ends long tube
fe = the eyepiece has a focal length =1.70 cm
Let:s f0 = the required focal length of object
The given length of the long tube and the focal length of eyepiece using this formula
..........................(1)
a) The required focal length in cm of the objective lens is =
b)
The angular magnification of the telescope is M,
..........................(2)
where
fe = 1.70 cm
from equation (2)
[There the negative sign indicates inverted image.]
the angular magnification of the telescope is = 25.47
ANSWER""". a) 43,3 cm
b) 25.47 cm