Author Question: A double-concave lens has equal radii of curvature of 15.1 cm. An object placed 14.2 cm from the ... (Read 30 times)

viki · **on:** Jul 29, 2018

A double-concave lens has equal radii of curvature of 15.1 cm. An object placed 14.2 cm from the lens forms a virtual image 5.29 cm from the lens. What is the index of refraction of the lens material?

A) 1.90
B) 1.98
C) 1.82
D) 1.77

Question 2

If you rub two transparency sheets with tissue and then hold the two transparency sheets at rest a short distance apart, the electromagnetic forces they exert on each other will be

A) magnetic but not electric. B) electric but not magnetic.
C) zero. D) both electric and magnetic.