1.

A compound microscope has an objective of focal length `1 cm` and an eye piece of focal length `2.5 cm` away frm the object has to be placed at a distance of `1.2 cm` away from the objective for normal adjustment. Find the angular mignification and length of the microscope tube.

Answer» Here, `f_(0) = 1 cm, f_(e) = 2.5 cm`.
`u_(0) = - 1.2 cm, m = ? L = ?`
As `(1)/(v_(0)) - (1)/(u_(0)) = (1)/(f_(0))`
`:. (1)/(v_(0)) = (1)/(f_(0)) + (1)/(u_(0)) = (1)/(1) - (1)/(1.2) = (0.2)/(1.2)`
`v_(0) = 1.2//0.2 = 6 cm`
As `m = (v_(0))/(|u_(0)|)(1 + (d)/(f_(e)))`
`:. m = (6)/(1.2)(1 + (25)/(2.5)) = 55`
`L = v_(0) + f_(e) = 6 + 2.5 = 8.5 cm`


Discussion

No Comment Found

Related InterviewSolutions