Questions

MCQ

🎯

Test yourself on this topic

8 questions · timed · auto-graded

MCQ 11 Mark
To an astronaut in a space-ship, the earth appears:
  • A
    white
  • B
    Rad
  • blue
  • D
    black
Answer
Correct option: C.
blue
To an astronaut in a space-ship, the earth appears blue due to the large scattering of blue colour of the sunlight by the atmosphere.
View full question & answer
MCQ 21 Mark
In white light of sun, maximum scattering by the air molecular present in the earth’s atmosphere is for :
  • A
    Red colour
  • B
    Yellow colour
  • C
    Green colour
  • Blue colour
Answer
Correct option: D.
Blue colour
Blue colour

Hint: When light of certain frequency falls on that atom or molecule, this atom or molecule responds to the light, whenever the size of the atom or molecule comparable to the wavelength of light. The sizes of nitrogen and oxygen molecules in atmosphere are comparable to the wavelength of blue light. These molecules act as scattering centers for scattering of blue light. This is also the reason that we see the sky as blue.

View full question & answer
MCQ 31 Mark
A radiations A is focused by a proper device on the bulb of a thermometer. Mercury in the thermometer shows a rapid increase. The radiations A is : ________ .
  • Infrared radiation
  • B
    Visible light
  • C
    Ultra-violet radiation
  • D
    X-rays
Answer
Correct option: A.
Infrared radiation
Infrared radiation

Hint: Infrared radiations produce strong heating effect.

View full question & answer
MCQ 41 Mark
The source of ultraviolet light is : ________ .
  • A
    Electric bulb
  • B
    Red hot iron ball
  • C
    Sodium vapour lamp
  • Carbon arc-lamp
Answer
Correct option: D.
Carbon arc-lamp
Carbon arc-lamp
View full question & answer
MCQ 51 Mark
The most energetic electromagnetic radiations are : ________ .
  • A
    Microwaves
  • B
    Ultraviolet waves
  • C
    X-rays
  • Gamma rays
Answer
Correct option: D.
Gamma rays
gamma rays
View full question & answer
MCQ 61 Mark
The wavelength range of white light is : ________ .
  • A
    4000 nm to 8000 nm
  • B
    40 nm to 80 nm
  • 400 nm to 800 nm
  • D
    4 nm to 8 nm
Answer
Correct option: C.
400 nm to 800 nm
The wavelength range for white light is 400 nm to 800 nm or 4000 Å to 8000 Å.
View full question & answer
MCQ 71 Mark
In the spectrum of white light by a prism, the colour at the extreme end opposite to the base of prism is : ________ .
  • A
    Violet
  • B
    Yellow
  • Red
  • D
    Blue
Answer
Correct option: C.
Red
The colour of the extreme end opposite to the base of the prism is red.

Hint: The angle of deviation decreases with the increase in wavelength of light for a given angle of incidence. Since the red light has greatest wavelength, it gets deviated the least and is seen on the extreme end opposite to the base of prism.

View full question & answer
MCQ 81 Mark
When a white light ray falls on a prism, the ray at its first surface suffers.
  • A
    No refraction
  • B
    Only dispersion
  • C
    Only deviation
  • Both deviation and dispersion
Answer
Correct option: D.
Both deviation and dispersion
Both deviation and dispersion.

Hint: When a white light ray falls on the first surface of a prism, light rays of different colours due to their different speeds in glass get refracted (or deviated) through different angles. Thus, the dispersion of white light into its constituent colours takes place at the first surface of prism.

View full question & answer
MCQ - Physics STD 10 Questions - Vidyadip