Tag: spectra

Quizzes (2) Questions (122)

Questions Related to spectra

Multiple choice physics spectra sunlight - white and coloured sunlight - combination of 7 lights fibre optics basics

When light passes through a medium that consists of scatters such as water vapour, dust particles, which colour of light experiences highest scattering?

  1. $Violet$
  2. $Red$
  3. $Yellow$
  4. $Orange$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Violet have least wavelength among the visible light spectra.

       According to Rayleigh Criterion,  Scattering probability is proportional to $\dfrac{1}{\lambda^4}$.
So, violet light will be scattered the most.

Multiple choice physics spectra sunlight - white and coloured sunlight - combination of 7 lights fibre optics basics

When light enters a dispersive medium, light wave of different wavelength travels with different velocities.

  1. Yes

  2. No

  3. Sometimes

  4. When medium is a fibre
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, speed becomes different for different wavelengths in a particular medium. In a given dispersive medium the speed for different colours is different and due to this phenomenon we can see the spectrum of VIBGYOR.

Multiple choice physics spectra sunlight - white and coloured sunlight - combination of 7 lights fibre optics basics

Assertion: Different colours travel with different speed in vacuum.
Reason : Wavelength of light depends on refractive index of medium.

  1. Both assertion and reason are true but the reason is the correct explanation of assertion

  2. Both assertion and reason are true but the reason is not the correct explanation of assertion

  3. Assertion is true but reason is false

  4. Both the assertion and reason are false

  5. Reason is true but assertion is false
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

In vacuum all the colours have same velocity but their velocity changes when they enter in a medium. In the medium their velocity changes due to change in their wavelength.
$v=n\lambda $
If $\lambda $ changes, v also changes for a particular colour therefore, different colours have different wavelength ($\lambda $).

Multiple choice physics spectra sunlight - white and coloured sunlight - combination of 7 lights fibre optics basics

What is known as dispersion of light?

  1. The phenomenon due to which a polychromatic light, like sunlight, splits into its component colours, when passed through a transparent medium

  2. The phenomenon due to which a polychromatic light, like sunlight, splits into its component colours, when passed through a opaque medium

  3. The phenomenon due to which a polychromatic light, like sunlight, splits into its component colours, when passed through a translucent medium

  4. The phenomenon due to which a polychromatic light, like sunlight, do not splits into its component colours, when passed through a transparent medium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When white light pass through a glass prism the white light get scatter in so many colours of light according to it's frequency and the lights are (VIBGYOR) ,this phenomena of scattering of light is called
dispersion of light.

Image result for What is known as dispersion of light?

Multiple choice physics spectra sunlight - white and coloured sunlight - combination of 7 lights fibre optics basics

Due to which property of colours they appear differently though the sunlight is passed through only one medium?

  1. Due to different refractive index with respect to medium

  2. Due to different frequencies with respect to medium

  3. Due to different amplitudes with respect to medium

  4. Due to different colour with respect to medium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Refraction is a phenomenon that happens when a beam of white light passes through the interface between air and a denser medium, such as glass or water. Light travels more slowly in a denser medium, so it changes direction – or refracts – when it passes through the interface. White light is a mixture of all the wavelengths of light, and each wavelength refracts at a slightly different angle. Therefore, when the beam emerges from the denser medium, it has been split into its component wavelengths. The ones you can see form the familiar rainbow

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

We consider the radiation emitted by the human body. Which of the following statements is true :

  1. The radiation emitted is in the infrared region

  2. The radiation is emitted only during the day

  3. The radiation is emitted during the summers and absorbed during the winters

  4. The radiation emitted lies in the ultraviolet region and hence is not visible
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Every body at all time, at all temperatures emit radiation (except at T = 0), which fall in the infrared region.