Two identical thin plano-convex glass lenses (refractive index 1.5) each having

Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of 20 cm are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is

Options

(a) (-20 cm)
(b) (-25 cm)
(c) (-50 cm)
(d) 50 cm

Correct Answer:

(-50 cm)

Explanation:

No explanation available. Be the first to write the explanation for this question by commenting below.

admin:

Related Questions

  1. The frequency of fundamental tone in an open organ pipe of length
  2. Volume of gas becomes four times if temperature becomes
  3. The cadmium rods are used in nuclear reactor to
  4. A device which converts electrical energy into mechanical energy is
  5. When an α-particle of mass m moving with velocity ν bombards on a heavy nucleus