A double-concave lens has equal radii of curvature of 15.1 cm. An ...

[viki]

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.

[Amiracle]

Answer to Question 1

A

Answer to Question 2

B

[viki]

Excellent

[parshano]

Gracias!