Sat February 16, 2013 By:

Using lens maker's formula for a equi-convex lens calculate the effect of breaking the lens into two equal halves lengthwise??

Expert Reply
Tue February 19, 2013
The relation between the focal length, f, and radius of curvatures R 1 and R 2 is given by the lens makers formula. The lens maker formula for concave lens is,    where µ is the refractive index of the material of the lens. where R1 and R2 are negative for concave surfaces.
 for diverging lens 1/f= ( ?-1)[-1/R -1/R] Thus, f= -R/[2( ?-1)]For each plano concave lens: 1/f' = ( ?-1)[-1/R -1/?] Thus    f'= -R/[( ?-1)]. Hence f' =2 f. The focal length of each half part will be twice the focal length of diverging lens.
Sat October 22, 2016


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