Q.43

Expert-verified
Found in: Page 1019

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

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

# High-power lasers are used to cut and weld materials by focusing the laser beam to a very small spot. This is like using a magnifying lens to focus the sun light to a small spot that can burn things. As an engineer you have designed a laser cutting device in which the material to be cut is placed behind the lens. you have selected a high-power laser with a wavelength of your calculation indicates that the laser must be focused to a spot in order to have sufficient power to make the cut. what is the minimum diameter of lens you must install?

The minimum diameter of the lens is.

See the step by step solution

## Step 1: Given information

We have given that:

High power laser wavelength

Laser cutting device

sufficient power to cut laser

we need to find the diameter of lens to install.

## Step 2: Simplification

Let us use this formula,

Here, is the focal length, is wavelength and is the value for laser must be focused.

Now multiplying both sides by D,

Dividing both the sides by ,

Let us substitute values in the equation,

Here, is the diameter of the lens.