An equiconvex lens of glass(μg=1.5) of focal length 10 cm is silvered on one side. It will behave like a

For equiconvex lens of glass with μg=1.5,  |R1|=|R2|=f=10 cm.                  Power of silvered lens P=2 PL+PM−1F=2(μ−1)(1R1−1R2)−2R2       =2(1.5−1)(110−1−10)−2−10       =15+15=25F=−2.5 cm.Therefore, equiconvex lens silvered at one face behaves as a concave mirror of focal length 2.5 cm.