Question

aloha users!!

____________

answer only if you know and can give proper explanation.

( question-3 )

◆◆ give answer + explanation◆◆

____________________________

thank you

Answer 1

Degree of convergence/divergence by a lense depends on The Optical Power, that is the inverse of the focal length.

Since, convex lens is the one that converges,

The answer is gonna be of that.

Now, let's check which of the convex lenses' power is more:

(1) F= 20 cm, P = 1/20 = 0.05 D

(2) F = 10 cm, P=1/10 = 0.10 D

Since the power of the convex lens with 10 cm of focal length is more, it converges Ray's more than the 20 cm one.

Hence, your answer is option (2)

Answer 2

Thicker lenses having greater curvature bend the light more and thus have shorter focal length. Thicker convex lenses have more converging power. If the parallel beams incident on the lens are inclined to the principle axis they converge after refraction to certain points to a plane containing the focal point.
Thus the answer must be option 2.
Convex lens of focal length 10 cm.