A compound microphone has an objective of focal length 1 cm and an eyepiece of focal length 2.5 cm. An object has to be placed at a distance of 1.2 cm away from the objective for normal adjustment. a.Find the angular magnification. b.Find the length of the microscope tube.

Answer

C

Explanation

Here, `f_0=1cm, f_e=5cm
mu_0=0.5cm, v_e=30cm`
`:. 1/v_0-1/u_0=1/f_0`
`rarr 1/v_0+1/0.5=1/1`
`rarr v_0=-1cm`
Again `1/v_e-1/u_e=1/f_e`
`=1/30-1/u_=1/5`
`rarr -1/u_e=1/5-1/30=(6-1)/30=1/6`
`pgt u_e=-6cm`
here separation between objective and eye piece =6-1=cm.