Q.7

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Found in: Page 1016

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# A diffraction-limited lens can focus light to a 10diameter spot on a screen. Do the following actions make the spot diameter larger, make it smaller, or leave it unchanged? A. Decreasing the wavelength of the light.B. Decreasing the lens diameter. C. Decreasing the lens focal length. D. Decreasing the lens-to-screen distance.

(A) Decrease

(B) Increase

(C) Decrease

(D) Increase

See the step by step solution

## Part A).Step.1 Given Information

Decreasing the wavelength of the light.

## Part A) Step 2.simplify

since ,hence from this dependence we have

Decreasing decreases

## Part b).step 1. Given statement

Decreasing the lens diameter

## Part b).Step 2.simplify

we know that

Therefore, Decreasing D increases

## Part C).Step 1.Given statement

Decreasing the lens focal length.

## Part C) Step 2.simplify

we have,

Therefore, Decreasing the focal length f will decreases

## Part D) Step 1.Given Information

Decreasing the lens-to-screen distance.

## Part D) Step 2.simplify

we know that

Decreasing the lens-to-screen distance means the screen is farther from the focal plane. This mean spot will get larger.