Question

What is the relationship between wavelength of the colors of light to the energy it posses?

A. Longest wavelength has the greatest energy
B. Longest wavelength has the least energy
C. Shortest wavelength has the least energy
D. Both A and B
2. Which statement explains the appearance of rainbow in the sky after a rainstorm ?

A. Raindrops act as prisms separating sunlight into colors.
B. The white clouds are actually prisms composed of different colors.
C. The colors of the rainbow come from raindrops in the atmosphere.
D. When the sunlight is reflected by the ground towards the clouds, it separates into different colors.
3. Which of the following explains why a red rose appears red ?

A. absorb the red color and reflect all others.
B. reflect the red color and absorb all others.
C. transmit all colors except red.
D. transmit the red color and reflect all others.
4. Which of the following gives explanation when a stick partly submerged obliquely in water appears to be bent at a point where it enters the water surface?

A. Dispersion of light on entering water
B. Light does not travel in straight line in water.
C. Diffraction of light by the surface of the water
D. Refraction of light due to differences in speed of light in air
5. What is the relationship of the frequency of colors of light to the energy it possess?

A. Highest frequency of the colors of light has the greatest energy.
B. Lowest frequency of the colors of light has the least energy.
C. Highest frequency of the colors of light has the least frequency.
D. Both A and B
6. What is the arrangement of colors when light strikes a prism?

A. Colors of light are arranged as ROYGBIV
B. Colors of light are arranged as YORVIBG
C. Colors of light are arranged as BIVGYOR
D. Colors of light are arranged as VIGB YGOR
7. What property of light is responsible for the formation of colors ?

A. amplitude
B. quality
C.velocity
D. wavelength
8. Which of the following statements is NOT true about the dispersion of sunlight by a prism?

A. The color most bent is red
B. White light consists of waves of varying length.
C. Different wavelengths travel with different speed.
D. Different wavelengths correspond to different color
9. What will happen to speed of light when light travels from air to glass ?

A. increases
B. decreases
C. remains the same
D. increases then decreases
10. Why a piece of coal appears black when viewed in sunlight ?

A because it absorbs all the light that b falls on it
B. because it disperses all the light that falls on it.
C. because it reflects all the light that falls on it
D. Because it transmits all the light that falls on it
11. What will happen if light hits a smooth surface?.

A. bent around corners
B. polarized
C. reflected
D. Refracted
12. The sun appears to be more reddish at sunset than at noon. Which of the following phenomena is responsible for this effect?

A. dispersion
B. interference
C. reflection
D. Scattering
13. Which colors of light has the most energy?
1 point
A. Red
B. Blue
C. Violet
D. Yellow
14. What would happen to the energy of the colors of light as the temperature rises?

A. The colors of light will have high energy
B. The colors of light will have low energy
C. The colors of light will have the same energy
D. The colors of light will not obtain energy
15. Which colors of light has the highest frequency?

A. Red
B. Blue
C. Violet
D. Yellow
​

Answer 1

(D)

(C)

(A)

(B)

(C)

(B)

(D)

(D)

(D)

(A)

(C)

(C)

(D)

(A)

(C)

Answer 2

1. B. Longest wavelength has the least energy.
2. A. Raindrops act as prisms separating sunlight into colours.
3. B. reflect the red colour and absorb all others.
4. D. Refraction of light due to differences in speed of light in air.
5. A. Highest frequency of the colours of light has the greatest energy.
6. A. Colours of light are arranged as ROYGBIV.
7. D. wavelength.
8. A. The colour most bent is red.
9. B. decreases.
10. A. because it absorbs all the light that falls on it.
11. C. reflected.
12. D. Scattering.
13. C. Violet.
14. A. The colours of light will have high energy.
15. C. Violet

Explanation:

1. From Planck's equation: $E=hv$, where $E$ is the energy of wave, $h$ is the planck's constant which is equal to $6.626*10^-34} J.s$ and $v$ is the frequency of the wave. λ$v=c$, where λ is the wavelength of wave. So, wavelength is greatest for low energy.
2. After rainfall, water drops in the atmosphere acts as prism for the sunlight and it gets separated into seven colours.
3. Colour of any object is the wavelength that it reflected by the object which reaches our eye and colour is observed. Rose appears red because it reflects wavelength of light which is red in colour.
4. When light travels from one medium to another, light undergoes refraction because of variable densities of the medium. And this is why light slows down in denser medium and appears as bent. A stick partly submerged obliquely in water appears to be bent at a point where it enters the water surface because of refraction of light.
5. $E=hv$, where $E$ is the energy of wave, $h$ is the Planck's constant which is equal to $6.626*10^-34} J.s$ and $v$ is the frequency of the wave. So, highest frequency has greatest energy.
6. The arrangement of colours is in order of which bends more and which colour wavelength bends less. Red bends least and violet bends most and the order is : Red. Orange, Yellow, Green, Blue, Indigo, Violet.
7. Formation of colours is due to presence of different wavelengths in light rays.
8. Red is the least bent wavelength in dispersion phenomenon of light. It has the highest wavelength and lowest frequency and so the energy is also less.
9. When light travels from air to glass, its velocity decreases because the density of glass in denser than air.
10. A piece of coal appears black when viewed in sunlight because all the wavelengths are absorbed by the coal and that is why it appears dark or black.
11. If light hits a smooth surface, it gets reflected as the wave bounces off the surface without any refraction.
12. Scattering of light is responsible for sun appearing more reddish at sunset than at noon.
13. $E=hv$, where $E$ is the energy of wave, $h$ is the Planck's constant which is equal to $6.626*10^-34} J.s$ and $v$ is the frequency of the wave. So, highest frequency has greatest energy. Violet has the highest frequency and hence highest energy.
14. Energy of photons increases when temperature increases. So, colours of light will have high energy when temperature rises.
15. Violet has the highest frequency which is $7.50*10^{14} Hz$ and least wavelength i.e. $400 nm$.