Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

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

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

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The shortest wavelength (lambda_min) of X-rays is determined by the Duane-Hunt law, which states that lambda_min = hc / eV. This shows that the minimum wavelength depends inversely on the accelerating voltage (V).

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

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:-

  1. $0.2 \ mm^{-1}$
  2. $0.4 \ mm^{-1}$
  3. $0.6 \ mm^{-1}$
  4. $0.8 \ mm^{-1}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice detection and recording of x-ray images option c: imaging physics

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

  1. Compton recovery wavelength

  2. Scattered wavelength of photon

  3. Compton wavelength of electron

  4. Compton wavelength of photon
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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

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

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

The compton wavelength shift depends on

  1. Wavelength of the incident photon

  2. Material of the scatterer

  3. Energy of the incident photon

  4. Scattering angle
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

So, the answer is option (D).

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

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:

  1. 0.0121 $A^{0}$
  2. 0.0484 $A^{0}$
  3. 0.0242 $A^{0}$
  4. 0.0363 $A^{0}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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

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

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

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

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

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

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 $A^o$

  1. 0.508

  2. 0.408

  3. 0.232

  4. 0.208
Reveal answer Fill a bubble to check yourself
D Correct answer
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).

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

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

  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
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

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.

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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

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

The value of Compton wavelength of electron is

  1. $0.0243$ $A^{0}$
  2. $0.243$$A^{0}$
  3. $2.43 $$A^{0}$
  4. $24.3 $$A^{0}$
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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