Chapter 4: Dispersion of Light - Science Mcqs for Grade 7 - Set 8

1)   The use of total internal 'reflection' of light is to

a. shape diamonds
b. straighten mirrors
c. check the surface of glass
d. check the density of liquids
Answer  Explanation 

ANSWER: shape diamonds

Explanation:
No explanation is available for this question!


2)   The critical angle for glass is

a. 40 degree
b. 41 degree
c. 42 degree
d. 43 degree
Answer  Explanation 

ANSWER: 41 degree

Explanation:
No explanation is available for this question!


3)   Yellow lights stimulate

a. red and blue cones
b. red and green rods
c. red and green cones
d. red and blue rods
Answer  Explanation 

ANSWER: red and green cones

Explanation:
No explanation is available for this question!


4)   Each ray of light is

a. reflected in the droplet
b. refracted in the droplet
c. dispersed in the droplet
d. converted to other forms of light in the droplet
Answer  Explanation 

ANSWER: dispersed in the droplet

Explanation:
No explanation is available for this question!


5)   If a ray of light enters the surface of diamond at an angle of 24 Degree or more, the light would

a. end
b. reflect back
c. refract at a greater angle
d. totally internally reflect
Answer  Explanation 

ANSWER: totally internally reflect

Explanation:
No explanation is available for this question!


6)   The higher the "refractive index"

a. the less the light bends
b. the more the light bends
c. the more the light speeds up
d. the less the light slows down
Answer  Explanation 

ANSWER: the more the light bends

Explanation:
No explanation is available for this question!


7)   A line drawn at right angle to the plane is known as

a. critical angle
b. critical plane
c. perpendicular plane
d. normal
Answer  Explanation 

ANSWER: normal

Explanation:
No explanation is available for this question!


8)   In optical fiber, the data is transferred in form of

a. sound
b. vacuum
c. light
d. heat
Answer  Explanation 

ANSWER: light

Explanation:
No explanation is available for this question!


9)   The number of the most common shapes of lenses are

a. 1
b. 2
c. 3
d. 4
Answer  Explanation 

ANSWER: 2

Explanation:
No explanation is available for this question!


10)   An example of object that uses concave lenses, is

a. contact lenses
b. telescope
c. spectacles
d. microscope
Answer  Explanation 

ANSWER: spectacles

Explanation:
No explanation is available for this question!


11)   The lens in our eye can change its thickness due to

a. muscles connection
b. brain power
c. will power
d. living cells
Answer  Explanation 

ANSWER: living cells

Explanation:
No explanation is available for this question!


12)   The number of cone cells in an eye is

a. 2 million
b. 4 million
c. 6 million
d. 8 million
Answer  Explanation 

ANSWER: 6 million

Explanation:
No explanation is available for this question!


13)   We can see things because they

a. absorb light
b. reflect light
c. create light
d. stimulate the photons of light
Answer  Explanation 

ANSWER: reflect light

Explanation:
No explanation is available for this question!


14)   We see different colors on screen because dots change their

a. colors
b. brightness
c. sharpness
d. size
Answer  Explanation 

ANSWER: brightness

Explanation:
No explanation is available for this question!


15)   The critical angle is basically the

a. angle of incidence
b. angle of refraction
c. angle of reflection
d. angle of rarefaction
Answer  Explanation 

ANSWER: angle of incidence

Explanation:
No explanation is available for this question!


16)   For long-sightedness, the lenses that are used, are

a. convex
b. concave
c. biconcave
d. flat lenses
Answer  Explanation 

ANSWER: convex

Explanation:
No explanation is available for this question!


17)   Converging means to

a. spread out
b. invert
c. bring together
d. shrink
Answer  Explanation 

ANSWER: bring together

Explanation:
No explanation is available for this question!


18)   A color filter removes

a. bright colors
b. dull colors
c. unwanted colors
d. wanted colors
Answer  Explanation 

ANSWER: unwanted colors

Explanation:
No explanation is available for this question!


19)   Light travels in

a. vacuum only
b. curled lines
c. straight lines
d. air only
Answer  Explanation 

ANSWER: straight lines

Explanation:
No explanation is available for this question!


20)   When light enters water from air, its speed decreases to

a. 20,000 km/s
b. 25,000 km/s
c. 200,000 km/s
d. 250,000 km/s
Answer  Explanation 

ANSWER: 250,000 km/s

Explanation:
No explanation is available for this question!


21)   The lenses work due to the

a. reflection of light
b. refraction of light
c. rarefaction of light
d. all of them
Answer  Explanation 

ANSWER: refraction of light

Explanation:
No explanation is available for this question!


22)   Diverging means to

a. spread out
b. invert
c. bring together
d. magnify
Answer  Explanation 

ANSWER: spread out

Explanation:
No explanation is available for this question!


23)   An example of luminous objects is

a. Moon
b. Earth
c. Sun
d. Wall
Answer  Explanation 

ANSWER: Sun

Explanation:
No explanation is available for this question!


24)   When light travels through a transparent object, it

a. reflects
b. refracts
c. speeds up
d. changes color
Answer  Explanation 

ANSWER: refracts

Explanation:
No explanation is available for this question!


25)   Our brain mixes the colors by

a. mixing the rods
b. mixing the cones
c. combining the signals from rods
d. combining the signals from cones
Answer  Explanation 

ANSWER: combining the signals from cones

Explanation:
No explanation is available for this question!


26)   The color that is not part of the spectrum is

a. blue
b. brown
c. indigo
d. violet
Answer  Explanation 

ANSWER: brown

Explanation:
No explanation is available for this question!


27)   When light enters a denser medium, it bends

a. away from the normal
b. towards the normal
c. away from the plane
d. towards the plane
Answer  Explanation 

ANSWER: towards the normal

Explanation:
No explanation is available for this question!


28)   Objects that let some light to pass through are known as

a. transparent objects
b. opaque objects
c. translucent objects
d. half transparent objects
Answer  Explanation 

ANSWER: translucent objects

Explanation:
No explanation is available for this question!