Flag Wave Motion> A convex lens of diameter 8.0 cm is used ...
question mark

A convex lens of diameter 8.0 cm is used to focus a parallel beam of light of wavelength 620 nm. If the light be focused at a distance of 20 cm from the lens, what would be the radius of the central bright spot formed?

Simran Bhatia , 11 Years ago
Grade 11
anser 1 Answers
Aditi Chauhan

Last Activity: 11 Years ago

Sol. . For first minimum diffraction, b sin θ = λ Here, θ = 30°, b = 5 cm ⇒ λ = 5 * sin 30° = 5/2 = 2.5 cm.

star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments