Tag: electromagnetic spectrum

Questions Related to electromagnetic spectrum

The structure of solids is studied by

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. X-rays

  2. $\gamma-rays$

  3. Cosmic rays

  4. Infrared rays

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Correct Option: A

If a source of power $4\ kW$ produces $10^{20}$ photons/second, the radiation belongs to a part of the spectrum called:-

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. $\gamma$-rays

  2. $X$-rays

  3. Ultraviolet rays

  4. Microwave

Show answer
Correct Option: B
Explanation:

$4\times { 10 }^{ 3 }={ 10 }^{ 20 }\times h\nu$ 

where $\nu=$frequency
$\nu =\cfrac { 4\times { 10 }^{ 3 } }{ { 10 }^{ 20 }\times 6.023\times { 10 }^{ -34 } } $
$\nu =6.64\times { 10 }^{ 16 }Hz$
This frequency lies in the spectrum of X-rays.

When accelerating voltage is increased from $10\ kV$ to $20\ kV$ in an X-ray tube, the gap between the wavelengths of $K _{\alpha}$ line and lowest end of continuous spectrum increases three times. The atomic number of the target element is:-

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. $29$

  2. $27$

  3. $25$

  4. $23$

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Correct Option: A

The radio waves of frequency 30 MHz to 300 MHz belong to:

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. high frequency band

  2. very high frequency band

  3. ultra high frequency band

  4. super high frequency band.

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Correct Option: B

If the source of power $4kwW$ produces $10^20$ photons/second, the radiation belongs to the part of a spectrum called

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. X rays

  2. Ultraviolet rays

  3. Microwaves

  4. Gamma rays

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Correct Option: A

A wave has wavelength $50A^o$. Which of the following is a use of this wave?

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. in detection of fracture in bones.

  2. in detection of planets

  3. in detection of water

  4. in detection of air

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Correct Option: A
Explanation:

X-rays has a wavelength of $50 \mathring{A}$.
X-rays are used by doctors to see inside people. The machines are managed by a trained x-ray technician. They pass easily through soft tissues, but not so easily through bones.
Hence, they help in detecting fractures in bones.

Name the radiations of wavelength just shorter than $4\times 10^{-7}m$.

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. Infraviolet

  2. Ultraviolet

  3. Infrared

  4. Ultrared

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Correct Option: B
Explanation:

The range of wavelength for visible light lies between, ${ 400 \ nm }<\lambda <{ 700 \ nm }$.

$\lambda $ just less than 400 nm is Ultraviolet.
$\lambda $ just greater than 700 nm is Infrared.

Name the radiation which can be detected by a thermophile.

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. infrared radiation

  2. ultraviolet radiation

  3. X-rays

  4. All of the above

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Correct Option: A

Name the rays or waves used for taking photographs in dark.

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. Infrared rays

  2. Ultraviolet rays

  3. X-rays

  4. Gamma rays

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Correct Option: A
Explanation:

Photographers use film that is sensitive to infrared rays to take pictures in places where there is no visible light. 
IR light is longer in wavelength than visible light and focuses differently. Regular photographic lenses are made for visible light photography without any regard to what happens when photographing out of band light like IR. Therefore each lens design and focal length, even each focal length within a zoom lens will focus IR light differently.
Hence, infrared light is used for taking pictures in the dark.

Name the rays or waves produced by the changes in the nucleus of an atom.

physics electromagnetic waves properties and uses of different radiation electromagnetic spectrum spectrum

  1. X-rays

  2. UV rays

  3. Gamma rays

  4. IR rays

Show answer
Correct Option: C
Explanation:

Gamma rays are classically produced by the decay of atomic nuclei as they transition from a high energy state to a lower state known as gamma decay, but may also be produced by other processes. Paul Villard, a French chemist and physicist, discovered gamma radiation in $1900$, while studying radiation emitted from radium. Villard's radiation was named "gamma rays" by Ernest Rutherford in $1903$.
Hence,  the rays or waves produced by the changes in the nucleus of an atom is Gamma rays.