Tag: the electromagnetic spectrum

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Questions Related to the electromagnetic spectrum

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

All components of the electromagnetic spectrum in vacuum have the same

  1. energy

  2. velocity

  3. wavelength

  4. frequency
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$Answer:-$ B 

speed of electromagnetic wave in vacuum  is given by:-
c(speed of light)=frequency$\times$ wavelength =$\dfrac{1}{\mu _0 \epsilon _0}$=constant
as we go from gamma rays to radio waves  frequency decreases and wavelength increases thereby maintaining the product constant.

 Energy is given by:- $E=h\nu$ since $\nu$ is different so energy is also different.
Also wavelength and frequency varies.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

Earth's atmosphere is transparent for

  1. only the visible light

  2. only the X-rays
  3. only the $\gamma$- rays

  4. visible light and microwaves
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Earth's atmosphere is divided into different layers, out of which the ozone layer absorbs the X-rays and $\gamma$-rays whereas visible light and microwaves are the waves which are not absorbed by any layer of atmosphere.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

In an electromagnetic spectrum, if the rays are placed in increasing order with respect to wavelength (i.e., from lower to higher wavelength); The following order is correct

  1. Radiowaves, microwave, infrared rays

  2. Gamma ray, X-ray, ultraviolet ray

  3. Ultraviolet ray, gamma ray, X-ray

  4. Microwave, infrared rays, radiowaves
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The electromagnetic spectrum in increasing order of wavelength is: Gamma rays, X-rays, Ultraviolet, Visible, Infrared, Microwave, Radio waves.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

PAR range of wavelength is 

  1. $400-700 nm$
  2. $400-800 nm$
  3. $450-950 nm$
  4. $500-600 nm$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Photosynthetically Active Radiation $(PAR)$ Is the amount of light available for photosynthesis, which is light in the $400$ to $700$ nanometer wavelength range. PAR changes seasonally and varies depending on the latitude and time of day.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

Electromagnetic waves that include light belong to

  1. light spectrum.

  2. electronic spectrum.

  3. electromagnet group.

  4. electromagnetic spectrum.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Electromagnetic waves do not include light belong to electromagnetic spectrum.

The the basic source of electromagnetic waves is an accelerated charge. This produces the changing electric and magnetic field which constitutes electromagnetic wave. An electromagnetic wave may have its wavelength varying from zero to infinity. The classification of electromagnetic waves according to frequency or wavelength is called the electromagnetic spectrum.

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

In electromagnetic spectrum, the frequencies of $\gamma$-rays and ultraviolet rays are denoted by $n _1, n _2$ and $n _3$ respectively then.

  1. $n _1 > n _2 > n _3$
  2. $n _1 < n _2 < n _3$
  3. $n _1 > n _2 < n _3$
  4. $n _1 < n _2 > n _3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Frequency range of Y rays=${ n } _{ 1 }=>3\times { 10 }^{ 20 }㎐$

Frequency range of ultraviolet rays$={ n } _{ 2 }=7.5\times { 10 }^{ 14 }-3\times { 10 }^{ 17 }㎐$
So frequency of $\gamma$ rays $>$ frequency of ultraviolet rays
${ n } _{ 1 } >{ n } _{ 2 }$

Multiple choice physics spectra the electromagnetic spectrum electromagnetic spectrum electromagnetic waves

The correct sequence of various regions in absorption spectrum is?

  1. Ultraviolet, visible, infra-red, microwave

  2. Microwave, visible, infra-red, X-rays

  3. Infra-red, gamma rays, ultraviolet, microwave

  4. Visible, ultraviolet, microwave, infra-red
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Absorption spectrum is inversly proportional to the wavelength of the wave.

So, the correct sequence will be Ultraviolet, visible, infra-red, microwave as ultraviolet has maximum wavelength and microwave have least wavelength.