MyQuestionIcon

1

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Lens Maker's Formula

When monochro...

Question

When monochromatic red light is used instead of blue light in a convex lens, its focal length will:

A

increase

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

B

decrease

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C

remain same

No worries! We‘ve got your back. Try BYJU‘S free classes today!

D

does not depend on colour of light

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A increase
The refractive index of a medium is inversely proportional to the wavelength of light used.
Thus, $μ_{R} < μ_{B}$
Now, $\frac{1}{f} = (μ - 1) (\frac{1}{R_{1}} - \frac{1}{R_{2}})$
Thus, $f_{R} > f_{B}$

Suggest Corrections

thumbs-up

0

Similar questions

Q. Assertion :The focal length of lens does not change, when red light is replaced by blue light. Reason: The focal length of lens does not depends on colour of light used.

Q. When red light is passing through a covex lens is replaced by light of blue colour , then how will the focal length of the lens change ??????

Q. Will the focal length of a lens for red light be more, same or less than that for blue light ?

f_{B}

f_{R}

are focal lengths of a convex lens for blue and red light respectively and

F_{B}

F_{R}

are the focal lengths of the concave lens for blue and red light respectively. We must then have :

Q. A parallel beam of monochromatic light falls on a combination of a convex lens and a concave lens of focal lengths 15 cm & 5 cm respectively.If the light emerges parallel from the concave lens. The distance between two lenses is

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Adaptive Q14

PHYSICS

Watch in App

explore_more_icon

Explore more

Lens Maker's Formula

Standard X Physics

Join BYJU'S Learning Program

CrossIcon