Tag: physics

Questions Related to physics

The shortest wavelength of X-rays emitted from an X-ray tube depends on

detection and recording of x-ray images option c: imaging physics

  1. The current in tube

  2. The voltage applied to the tube

  3. The nature of the gas in tube

  4. The atomic number of the target material

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Correct Option: B

The intensity of X-rays of wavelength $0. \mathring{A}$ reduces to one fourth on passing through $3.5 \ mm$ thickness of a metal foil. The coefficient of absorption of metal will be:-

detection and recording of x-ray images option c: imaging physics

  1. $0.2 \ mm^{-1}$

  2. $0.4 \ mm^{-1}$

  3. $0.6 \ mm^{-1}$

  4. $0.8 \ mm^{-1}$

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Correct Option: A

In Compton effect, the quantity $\dfrac{h}{m _{e}c}$ is called

detection and recording of x-ray images option c: imaging physics

  1. Compton recovery wavelength

  2. Scattered wavelength of photon

  3. Compton wavelength of electron

  4. Compton wavelength of photon

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Correct Option: C
Explanation:

$\lambda -\lambda ^{1}=\dfrac{h}{m _e c}(1-cos  \theta )$

where $\dfrac{h}{m _e c}$ is called compton wavelength.

The compton wavelength shift depends on

detection and recording of x-ray images option c: imaging physics

  1. Wavelength of the incident photon

  2. Material of the scatterer

  3. Energy of the incident photon

  4. Scattering angle

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Correct Option: D
Explanation:

$\lambda -\lambda ^{1}=\dfrac{h}{m _e c}\ (1+cos  \theta )$
where $\theta$ is scattering angle.

So, the answer is option (D).

Given $h = 6.62 \times 10^{-34}$ Js, $m _e$ $= 9.1 \times 10^{-31}$ kg, $c = 3 \times 10^{8}$ m/s, the value of Compton wavelength is:

detection and recording of x-ray images option c: imaging physics

  1. 0.0121 $A^{0}$

  2. 0.0484 $A^{0}$

  3. 0.0242 $A^{0}$

  4. 0.0363 $A^{0}$

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Correct Option: C
Explanation:

Compton wavelength $= \ \dfrac{h}{m _{e}c}$

$= \ \dfrac{6.62\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}$

$= \ 0.242\times 10^{-11}m$

$= \ 0.0242\times 10^{-10}m$

$= \ 0.0242\ A^{\circ}$

In Compton scattering process, the incident X-radiation is scattered at an angle $60^o$. The wavelength of the scattered radiation is $0.22 A^o$. The wavelength of the incident X-radiation in $A^o$

detection and recording of x-ray images option c: imaging physics

  1. 0.508

  2. 0.408

  3. 0.232

  4. 0.208

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Correct Option: D
Explanation:

By compton formula
$\Delta \lambda = \lambda _{f} -\lambda _{i}= \dfrac{h}{m _{e}C}(1-cos\theta )$

$0.22\ A^{\circ}-\lambda \ _{i}= 0.024A^{\circ}(1-\dfrac{1}{2}) \ \ \ \ (\because  cos60^{\circ}= 1/2)$

$\lambda   _{i}= 0.22-0.012$
$= 0.208  A^{\circ}$

So, the answer is option (D).

If the scattering angle of the photon in Compton effect is $180^{0}$, the Compton shift is

detection and recording of x-ray images option c: imaging physics

  1. Equal to the Compton wavelength of the electron

  2. four times the Compton wavelength of the electron

  3. two times the Compton wavelength of the electron

  4. half the compton wavelength of the electron

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Correct Option: C
Explanation:

$\lambda -\lambda ^{1}  =  \dfrac{h}{m _e c}(1-cos  \theta )$

where
$\lambda $ is initial wavelength
$\lambda^{1} $ is the wavelength after & scattering
$h$ is the plank constant
$m _e$ is the electron rest mass.
$c$ is the speed of light
$\theta $ is the scattering angle.

Consider the following statements A and B, identify the correct choice in the given answers. 

A) Tightly bound electrons of target material scatter X-ray photon,resulting in the Compton effect. 
B) Photoelectric effect takes place with free electrons.

detection and recording of x-ray images option c: imaging physics

  1. Both A and B are true

  2. A is true but B is false

  3. A is false but B is true

  4. Both A and B are false

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Correct Option: D
Explanation:

Compton effect happens with free electrons.
Photoelectric effect happens to bounded electrons.

The value of Compton wavelength of electron is

detection and recording of x-ray images option c: imaging physics

  1. $0.0243$ $A^{0}$

  2. $0.243$$A^{0}$

  3. $2.43 $$A^{0}$

  4. $24.3 $$A^{0}$

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Correct Option: A
Explanation:

The quantity $(\dfrac {h}{m _0c})$ is known as the  Compton wavelength of the electron; it is equal to $2.43\times 10^{-12}$ $m$ or $0.0243 A$. 


Here, $m _0$ is the ,electron rest mass.

How would you relate the new frequency to original one when an X-ray photon collides with an electron and bounces off ?

detection and recording of x-ray images option c: imaging physics

  1. Is lower than its original frequency

  2. Is same as its original frequency

  3. Is higher than its original frequency

  4. Depends upon the electrons frequency

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Correct Option: A
Explanation:

 From Scattering Formula
$\lambda'-\lambda=\dfrac{G}{M _{e}c}(1-cos \theta )$
We can see, $\lambda '> \lambda $
So $v'< v$