A concave mirror of focal length `20 cm` is cut into two parts from the middle and the two parts are moved perpendicularly by a distance `1 cm` from the previous principal axis `AB` .find the distance between the images formed by the two parts?

Options

A. 2 cm
B. 6cm
C. 3cm
D. 4cm

Answer

A

Explanation

For `M_(1): u=-10"cm"`
f=-20 cm , `h_(0)= -0.1 "cm"`
`v=(200)/(-10+20) = (200)/(10) implies v=20"cm"`
`m=-(v)/(u) implies (h_(1))/(h_(0)) = (+20)/(+10)`
`implies h_(1) = 2 xx -0.1 = -0.2 , h_(1) = -2` mm
For `m_(2) = (-20)/(-10) = 2 implies h_(1) = 0.2 "cm" = 2"mm"`