Question

A converging thin lens made out of crown glass (n=1.52) has a focal length f=1.0m An identical lens (same radius for the spherical surfaces), made out of a high-index plastic with n=1.70 will be ...

A. Converging with a focal length smaller than 1.0 m
B. Diverging with a focal length smaller than 1.0 m
C. Converging with a focal length exactly equal to 1.0 m
D. Converging with a focal length larger than 1.0 m
E. Diverging with a focal length larger than 1.0 m

Look up the lens maker's formula and decide for yourself.

The high-index plastic will have a shorter focal length than the glass lens with the same shape.

Focal length is inversely proportional to n-1.
oh k. got it. thanks

Related Questions

An object is placed 20.0 cm from a thin converging lens along the axis of the lens. If a real image... an object of 3cm length is placed 5cm away from thin converging lens. The image formed by the lens i... An object 2.00cm high is placed 40cm to the left of a converging lens having a focal length of 30cm.... determine the type and focal length of a lens that has the same power as a combination of a thin con...