# Spectrum MCQ Type Questions for ICSE Physics Class-10

Spectrum MCQ Type Questions for ICSE Physics Class-10 . These MCQ  / Objective Type Questions is based on latest reduced syllabus according 2021-22 session on bifurcated pattern. Main motto of MCQ Type Question is cracking the next upcoming exam of council. Visit official website CISCE for detail information about ICSE Board Class-10 Physics.

## MCQ Type Questions Spectrum for ICSE Class-10 Physics

 Board ICSE Class 10th (X) Subject Physics Chapter Spectrum Syllabus on bifurcated syllabus (after reduction) Session 2021-22 Topic MCQ / Objective Type Question

### ICSE Class-10 Physics  MCQ Type Questions of Spectrum

Question 1: 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

(d) Both deviation and dispersion

Answer (d) Both deviation and dispersion

Question 2:  In the spectrum of white light by a prism, the colour of the extreme end opposite to the base of prism is:

(a) Violet

(b) Yellow

(c) Red

(d) Blue

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.

Question 3: The wavelength range of white light is:

(a) 4000 nm to 8000 nm

(b) 40 nm to 80 nm

(c) 400 nm to 800 nm

(d) 4 nm to 8 nm

Answer (a) 4000 nm to 8000 nm

The wavelength range for white light is 400 nm to 800 nm or 4000 Å to 8000 Å.

Question 4: The frequency range of visible light is from 3.75 x 1014 Hz to 7.5 x 1014Hz. Calculate its wavelength range. Take the speed of light =3 x 108m/s.

(a) 14 x 1014Hz

(b) 7.0 x 1014Hz

(c) 7.5 x 1014Hz

(d) 8.5 x 1014Hz

Answer (a) (c) 7.5 x 1014Hz

Speed of light, c= 3x 108m/s

Frequency range=3.75 x 1014Hz to 7.5 x 1014Hz.

Speed of light = frequency x wavelength

For frequency=3.75 x 1014Hz

For frequency =7.5 x 1014Hz

Question 5: The most energetic electromagnetic radiations are:

(a) Microwaves

(b) Ultraviolet waves

(c) X-rays

(d) Gamma rays

Question 6: The source of ultraviolet light is:

(a) Electric bulb

(b) Red hot iron ball

(c) Sodium vapour lamp

(d) Carbon arc-lamp

Question 7: A radiation P is focused by a proper device on the bulb of a thermometer. Mercury in the thermometer shows a rapid increase. The radiation P is:

(b) Visible light

(d) X-rays

Hint: Infrared radiations produce strong heating effect.

Question 8: An electromagnetic wave has a frequency of 500MHz and a wavelength of 60cm. Calculate the velocity of the wave.

(a) 9 x 108m/s

(b) 6 x 108m/s

(c) 3.5 x 108m/s

(d) 3 x 108m/s

Frequency =500MHz =500 x 106Hz

Wavelength= 60 cm=0.6 m

Velocity of wave= frequency x wavelength

=500x 106 x 0.6=3 x 108m/s

Question 9: The wavelength of X-rays is 0.01 Å  . Calculate its frequency. State the assumption made, if any

(a) 3.5 x 1040 Hz

(b) 3 x 1040 Hz

(c) 3 x 1020 Hz

(d) 6 x 1020 Hz

Answer (c) 3 x 1020 Hz

Wavelength = 0.01 Å    = 0.01 x 10-10 m

Speed of X-rays =3 x 108m/s

Speed of light = frequency x wavelength

c = νλ

v = c/λ = 3 x 108/0.001 x 10-10 m

= 3 x 1020 Hz

Question 10: In the white light of Sun, maximum scattering by the air molecules present in the Earth’s atmosphere is for:

(a) Red colour

(b) Yellow colour

(c) Green colour

(d) 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.

Question 11: To an astronaut in a space-ship, the earth appears:

(a) White

(b) Red

(c) Blue

(d) black

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.

Question 12: Visible light has electromagnetic waves between :

(a) 8000 A° to 6000 A°
(b) 8000 A to 1000 A°
(c) 8000 A° to 4000 A°
(d) 8000 A to 2000 A°

Answer: (c) 8000 A° to 4000 A°

Question 13: 1 Angstrom unit (A°) is equal to :

(a) 10-10 m
(b) 10-12 m
(c) 10-8 m
(d) 106 m

Question 14: The most visible colour of visible spectrum is :

(a) blue
(b) red
(c) green
(d) orange

Question 15:  The band of seven colours formed, when white light passes through an equilateral prism is called :

(a) dispersion
(b) colour band
(c) spectrum
(d) none of these

Question 16: Violet, green, red and yellow are the four colours formed on a white screen when a polychromatic light is dispersed. The arrangement of colours in the decreasing order of wave lengths is :

(a) green, red, yellow and violet
(b) red, yellow, green and violet
(c) violet, green, yellow and red
(d) violet, green, red and yellow

Answer: (b) red, yellow, green and violet

Question 17: The angle of deviation is maximum for ……. when the dispersion of polychromatic light takes place

(a) red
(b) violet
(e) green
(d) blue

Question 18: Which is not a source of ultraviolet radiations ?

(a) Sun
(b) Arc lamp
(c) Electric heater
(d) Star

Question 19:  The electromagnetic radiation which are useful in night photography is:

(a) infrared rays
(b) ultraviolet rays
(e) visible light
(d) X-rays

Question 20:  The electromagnetic wave associated with high energy is:

(a) ultraviolet ray
(b) X-ray
(e) gamma ray
(d) infrared ray

Question 21: During the Sunset the colour which scatters closest to the eye of observer is:

(a) yellow
(b) red
(c) blue
(d) violet

Question 22:  Infrared rays with very large wavelength are easily reflected by

(a) air
(b) glass
(c) carbon dioxide molecules
(d) both (b) and (c)

Question 23:  X-rays are produced by

(a) oscillating circuits in special vacuum tubes
(b) excitation of outermost electronic shell of an atom
(c) excitation of inner electron of atom and is sudden annihilation of high energy free electrons.
(d) nucleus of an atom, by the destruction of high energy particle.

Answer: (c) excitation of inner electron of atom and is sudden annihilation of high energy free electrons.

Question 24: How does the speed of light in glass change on increasing the wavelength of light?

(a) decrease in the wavelength
(b) increase in the wavelength
(c) both (a) and (b)
(d) none of the above

Answer: (b) increase in the wavelength

Question 25: What is the range of wavelength of the spectrum of white light in nm?

(a) 4000 nm to 8000 nm
(b) 400 nm to 8000 nm
(c) 400 nm to 800 nm
(d) 4000 nm to 800 nm

Answer: (c) 400 nm to 800 nm

Question 26: The wavelengths for the light of red and blue colours are roughly 7.8 x 10-7m and 4.8 x 10-7 m respectively. Which colour has the greater speed in glass?

(a) In glass, blue light has a greater speed
(b) In glass, red light has a greater speed
(c) In glass, violet light has a greater speed
(d) none of the these

Answer: (b) In glass, red light has a greater speed

Question-26  which of the following is not a properties of ultra violet :

(a)They are electromagnetic waves and are not effected by: Electric Or Magnetic fields.

(b)They obey the laws of refraction and reflection.

(c)They travel with velocity 3 × 108 km/sec

(d)They produce chemical effect in silver salts

Answer: (c)They travel with velocity 3 × 108 km/sec

Question-27 which of the following is not a uses of U.V. :

(a) U.V. arc used to detect adulteration in ghee because of its property of fluorescence.

(b)Used to sterilise surgical instruments and drinking water.

(c) U.V. absorbed by skin stimulates body to produce vitamin D, which is very good for growth of bones and teeth.

(d) U.V. are used to ignite nuclear power plant

Answer: (d) U.V. are used to ignite nuclear power plant

Question-28 Which colour of white light is scattered the least

(a) blue
(b) Red
(c) violet
(d) purple

#### Question 29

four colours of the spectrum of white light which have wavelength longer than blue light.

a) blue green indigo
(b) Red green violet
(c) violet orange and red
(d) Green, Yellow orange and red

Answer: (d) Green, Yellow orange and red

–: End of Spectrum MCQ Type Questions for ICSE Physics Class-10 :-

-: also visit :-