Q: Given a double-slit experiment with slit separation $$d = 1.0 \text{ mm}$$, screen distance $$D = 1.0 \text{ m}$$, and light wavelength $$\lambda = 500 \text{ nm}$$, calculate the fringe separation $$\Delta y.$$

$$\Delta y = \frac{\lambda D}{d} = \frac{500 \times 10$$^{-9}$$ \times 1}{1.0 \times 10$$^{-3}$$} = 0.5 \text{ mm}$$

Q: A double-slit experiment is performed with $$\lambda = 600 \text{ nm}$$, $$d = 0.2 \text{ mm}$$, and $$D = 1.2 \text{ m}. $$What is the separation between adjacent bright fringes?

$$\Delta y = \frac{\lambda D}{d} = \frac{600 \times 10$$^{-9}$$ \times 1.2}{0.2 \times 10$$^{-3}$$} = 3.6 \text{ mm}$$

Q: A double-slit experiment is performed with $$d = 0.5 \text{ mm}$$, $$D = 2.0 \text{ m}$$, and $$\lambda = 650 \text{ nm}. $$What is the fringe separation?

$$\Delta y = \frac{650 \times 10$$^{-9}$$ \times 2.0}{0.5 \times 10$$^{-3}$$} = 2.6 \text{ mm}$$

Question 1

In Young's double-slit experiment, what is the condition for constructive interference (bright fringe) at a point on the screen?

Accepted Answer

$$d \sin 	heta = m \lambda$$

Question 2

If the distance between the double slits is doubled in Young's experiment, what happens to the fringe separation $$\Delta y$$?

Accepted Answer

$$\Delta y is $$halved

Question 3

Which of the following factors does NOT affect the fringe separation in Young's double-slit experiment?

Accepted Answer

The intensity of the light source

Question 4

Given a double-slit experiment with slit separation $$d = 1.0 	ext{ mm}$$, screen distance $$D = 1.0 	ext{ m}$$, and light wavelength $$\lambda = 500 	ext{ nm}$$, calculate the fringe separation $$\Delta y.$$

Accepted Answer

$$\Delta y = \frac{\lambda D}{d} = \frac{500 	imes 10$$^{-9}$$ 	imes 1}{1.0 	imes 10$$^{-3}$$} = 0.5 	ext{ mm}$$

Question 5

If the wavelength of light used in Young's experiment is increased, what happens to the fringe separation?

Accepted Answer

Fringe separation increases

Question 6

What is the formula for the position of the $$mth $$bright fringe in Young's double-slit experiment?

Accepted Answer

$$y_m = \frac{m \lambda D}{d}$$

Question 7

In a double-slit experiment, if the screen is moved farther from the slits, what is the effect on the fringe separation?

Accepted Answer

Fringe separation increases

Question 8

Which color of visible light produces the largest fringe separation in Young's double-slit experiment?

Accepted Answer

Red

Question 9

If the slit separation $$d is $$decreased while keeping $$\lambda$$ and $$D$$ constant, what happens to the fringe separation $$\Delta y$$?

Accepted Answer

$$\Delta y$$ increases

Question 10

A double-slit experiment is performed with $$\lambda = 600 	ext{ nm}$$, $$d = 0.2 	ext{ mm}$$, and $$D = 1.2 	ext{ m}. $$What is the separation between adjacent bright fringes?

Accepted Answer

$$\Delta y = \frac{\lambda D}{d} = \frac{600 	imes 10$$^{-9}$$ 	imes 1.2}{0.2 	imes 10$$^{-3}$$} = 3.6 	ext{ mm}$$

Question 11

In Young's double-slit experiment, what is the effect of using white light instead of monochromatic light?

Accepted Answer

Colored fringes are observed with a central white fringe

Question 12

What is the path difference for the $$mth $$bright fringe in Young's double-slit experiment?

Accepted Answer

$$m \lambda$$

Question 13

If the wavelength of light is changed from 500 nm to 400 nm in a double-slit experiment, what happens to the fringe separation?

Accepted Answer

Fringe separation decreases

Question 14

Which equation gives the separation between successive dark fringes in Young's double-slit experiment?

Accepted Answer

$$\Delta y = \frac{\lambda D}{d}$$

Question 15

A double-slit experiment is performed with $$d = 0.5 	ext{ mm}$$, $$D = 2.0 	ext{ m}$$, and $$\lambda = 650 	ext{ nm}. $$What is the fringe separation?

Accepted Answer

$$\Delta y = \frac{650 	imes 10$$^{-9}$$ 	imes 2.0}{0.5 	imes 10$$^{-3}$$} = 2.6 	ext{ mm}$$

Question 16

In Young's double-slit experiment, what is observed if the slits are illuminated with two different monochromatic lights simultaneously?

Accepted Answer

Two sets of fringes with different separations are observed

Question 17

If the order of the dark fringe is $$m$$, what is the position of the $$mth $$dark fringe?

Accepted Answer

$$y_{dm} = \frac{(m + \frac{1}{2}) \lambda D}{d}$$

Question 18

Why do the fringes in Young's double-slit experiment appear colored when white light is used?

Accepted Answer

Different wavelengths produce fringes at different positions

Question 19

In a double-slit experiment, what happens to the visibility of fringes if the slit width is increased significantly?

Accepted Answer

Fringes become less visible due to reduced coherence

Young’s Double-Slit Experiment: Principles, Analysis, and Applications

Study Guide - Practice Questions

Study Guide - Flashcards