Question 1

According to Huygens’ Principle, what happens at every point on a wavefront?

Accepted Answer

Each point acts as a source of new secondary wavelets that spread out in all directions with the same speed as the original wave.

Question 2

Which of the following best explains why diffraction is more pronounced when light passes through a very narrow slit?

Accepted Answer

The slit width becomes comparable to the wavelength of light, causing the waves to spread out more.

Question 3

A radio station uses long-wavelength radio waves for broadcasting. According to the principles of diffraction, what is an advantage of using longer wavelengths?

Accepted Answer

Longer wavelengths diffract more around obstacles, improving reception in areas with obstructions.

Question 4

Which equation describes the condition for constructive interference in a double-slit experiment?

Accepted Answer

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

Question 5

A thin film of oil on water appears colorful in sunlight. Which phenomenon is primarily responsible for this effect?

Accepted Answer

Interference of light reflected from the top and bottom surfaces of the oil film.

Question 6

If the thickness of a gasoline film on water decreases, which color is most likely to be canceled by interference?

Accepted Answer

A color with a shorter wavelength than blue.

Question 7

Which of the following statements about polarization is correct?

Accepted Answer

Only transverse waves, such as light, can be polarized.

Question 8

Why do electron microscopes achieve higher resolution than optical microscopes?

Accepted Answer

Electrons have much shorter wavelengths than visible light, reducing diffraction effects.

Question 9

A hologram requires the use of coherent light. What does it mean for light to be coherent?

Accepted Answer

All parts of the light wave have a constant phase relationship and a single frequency.

Question 10

In a double-slit experiment, what happens to the interference pattern if the wavelength of the light is increased?

Accepted Answer

The bright fringes move farther apart.

Question 11

Which of the following best describes the superposition principle?

Accepted Answer

The resultant displacement at any point is the sum of the displacements due to each wave at that point.

Question 12

A pair of Polaroid filters are placed at right angles to each other. What happens to the intensity of transmitted light?

Accepted Answer

No light is transmitted.

Question 13

Which of the following is a real-world application of polarization?

Accepted Answer

Reducing glare in sunglasses.

Question 14

If you observe blue light reflected from a thin film and then increase the angle of observation, what color are you likely to see?

Accepted Answer

A color with a shorter wavelength than blue.

Question 15

Which of the following is NOT a feature of diffraction?

Accepted Answer

It allows objects smaller than the wavelength of light to be imaged clearly.

Question 16

Which equation gives the path difference for destructive interference in a double-slit experiment?

Accepted Answer

$$d \sin 	heta = (m + 0.5) \lambda$$

Question 17

Why do dolphins use ultrasound for echolocation?

Accepted Answer

Ultrasound has a shorter wavelength, allowing dolphins to resolve finer details.

Question 18

Which device uses a diffraction grating to analyze the composition of light sources?

Accepted Answer

Spectrometer

Question 19

What is the main reason that objects smaller than the wavelength of light cannot be seen with an optical microscope?

Accepted Answer

Diffraction blurs the image, preventing resolution of small objects.

Chapter 29: Light Waves – Huygens’ Principle, Diffraction, Interference, Polarization, and Holography

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