Microwaves of wavelength 10.0 mm fall normally on a metal plate that contains a slit \(25 \mathrm{mm}\) wide. (a) Where are the first minima of the diffraction pattern? (b) Would there be minima if the wavelength were \(30.0 \mathrm{mm}\) ?

Short Answer

Expert verified
(a) The first minima of the diffraction pattern occurs at angles of approximately \(\pm 23.6^\circ\). (b) There would not be a minima if the wavelength were \(30.0\,\text{mm}\).

Step by step solution

01

Write down the given information and the single-slit diffraction formula

Given the wavelength (\(\lambda\)) of microwaves: \(10\,\text{mm}\), and the slit width (\(a\)): \(25\,\text{mm}\). The single-slit diffraction formula is: \[ \sin \theta = \frac{m\lambda}{a} \] where \(\theta\) is the angle between the central maximum and the m-th order minimum, and \(m\) is the order of the minima.
02

Calculate the angle for the first minima

In this problem, we need to find the angular positions of the first minima, so we will use \(m = 1\). Plugging the values into the formula, we have: \[ \sin \theta_1 = \frac{1 \times 10}{25} \] Now, calculate the value of \(\sin \theta_1\): \[ \sin \theta_1 = \frac{10}{25} = 0.4 \]
03

Calculate the angle for the first minima

To find the angle for the first minima (\(\theta_1\)), take the inverse sine of the obtained value: \[ \theta_1 = \sin^{-1}(0.4) \approx 23.6^\circ \]
04

Determine if there are minima with a wavelength of 30.0 mm

Now, we need to check if there would be minima for a wavelength of \(30.0\,\text{mm}\). Plugging the new wavelength value \(\lambda = 30.0\,\text{mm}\) and \(m = 1\) into the formula, we get: \[ \sin \theta'_1 = \frac{1 \times 30}{25} \] Calculate the value of \(\sin \theta'_1\): \[ \sin \theta'_1 = \frac{30}{25} = 1.2 \] Since \(\sin \theta'_1 > 1\), it's not possible to have a minima for a wavelength of \(30.0\,\text{mm}\).
05

Present the results

(a) The first minima of the diffraction pattern occurs at angles of approximately \(\pm 23.6^\circ\). (b) There would not be a minima if the wavelength were \(30.0\,\text{mm}\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free