Single Slit Diffraction Quiz: Trivia!

1. Bright spots on the interference pattern are visible because of:

Destructive Interference of Light

Constructive Interference of Light

Polarization of Light

Light is always bright

Your eyes are playing games with you!

Constructive interference means that the troughs and crests are lined up which means that the amplitude of the wave is increased and therefore there are bright spots.

Explanation

Constructive interference means that the troughs and crests are lined up which means that the amplitude of the wave is increased and therefore there are bright spots.

2. Light doesn't behave like a wave in Single Slit Interference.

True

False

If it didn't behave like a wave, then you wouldn't see diffraction patterns, therefore it must behave like a wave.

Explanation

If it didn't behave like a wave, then you wouldn't see diffraction patterns, therefore it must behave like a wave.

3. Single Slit interference can occur in a double-slit experiment if the slits are wider than the wavelength of light passing through them.

True

False

Single Slit interference occurs in any slit that is slightly larger than the wavelength of light that passes through it.

Explanation

Single Slit interference occurs in any slit that is slightly larger than the wavelength of light that passes through it.

4. A single slit 1.0mm wide is illuminated by 450nm light. What is the central maximum (in cm) width in the diffraction pattern on a screen 5.0m away?

3 cm

0.8 cm

0.45 cm

0.5 cm

None of the Above

Use the equation $«math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«msub»«mi»Y«/mi»«mi»n«/mi»«/msub»«mo»=«/mo»«mfrac»«mrow»«mi»n«/mi»«mi»§#955;«/mi»«mi»D«/mi»«/mrow»«mi»d«/mi»«/mfrac»«/math»$ with n = 1, λ = 450 * 10^-9m, D = 5.0m and d = 1 * 10^-3m. Find Yn and then multiply it by 2 to get the width of the central max.

Explanation

Use the equation $«math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«msub»«mi»Y«/mi»«mi»n«/mi»«/msub»«mo»=«/mo»«mfrac»«mrow»«mi»n«/mi»«mi»§#955;«/mi»«mi»D«/mi»«/mrow»«mi»d«/mi»«/mfrac»«/math»$ with n = 1, λ = 450 * 10^-9m, D = 5.0m and d = 1 * 10^-3m. Find Yn and then multiply it by 2 to get the width of the central max.

5. The equations for single slit interference are exactly the opposite as those for double-slit interference.

True

False

The equation for nodal lines in double slit is the same as antinodal lines in a single slit and the reverse is true as well.

Explanation

The equation for nodal lines in double slit is the same as antinodal lines in a single slit and the reverse is true as well.

6. In Single Slit Interference, there can be an infinite number of dark and bright fringes.

True

False

There is always a limited number of dark and bright fringes. This number depends on the maximum value of n which can be calculated by d/λ.

Explanation

There is always a limited number of dark and bright fringes. This number depends on the maximum value of n which can be calculated by d/λ.

7. When violet light of wavelength 415nm falls on a single slit, it creates a central diffraction peak that is 9.2 cm wide on a 2.55m away screen. How wide is the slit?

3 X 10^-8 meters

3.8 X 10^-7 meters

2.3 X 10^-7 meters

4.2 X 10^-6 meters

None of the Above

Remember to divide the 9.2 cm by 2 because the equations that we know are for the distance from the center for any 1 side. Then use the equation $«math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«msub»«mi»Y«/mi»«mi»n«/mi»«/msub»«mo»=«/mo»«mfrac»«mrow»«mi»n«/mi»«mi»§#955;«/mi»«mi»D«/mi»«/mrow»«mi»d«/mi»«/mfrac»«/math»$ and plug in the known values to find the answer.

Explanation

Remember to divide the 9.2 cm by 2 because the equations that we know are for the distance from the center for any 1 side. Then use the equation $«math xmlns=¨http://www.w3.org/1998/Math/MathML¨»«msub»«mi»Y«/mi»«mi»n«/mi»«/msub»«mo»=«/mo»«mfrac»«mrow»«mi»n«/mi»«mi»§#955;«/mi»«mi»D«/mi»«/mrow»«mi»d«/mi»«/mfrac»«/math»$ and plug in the known values to find the answer.

8. Which of the following is true for Nodes (minima) in Single Slit Diffraction?

None of the Above

The derivation to this is explained on the Single Slit Diffraction page on the website.

Explanation

The derivation to this is explained on the Single Slit Diffraction page on the website.

9. When does Single Slit Diffraction Occur?

When the Slit Width is smaller than λ

When the Slit Width is the same as λ

When the Slit Width is slightly larger than λ

Both A and B

Both B and C

Single Slit Diffraction occurs when the slit width is slightly greater than or equal to λ. When it is equal to λ, only the central maximum and 2 nodal points are visible, but diffraction still occurs.

Explanation

Single Slit Diffraction occurs when the slit width is slightly greater than or equal to λ. When it is equal to λ, only the central maximum and 2 nodal points are visible, but diffraction still occurs.