Tag: physics

Questions Related to physics

A photon collides with an electron and gets scattered through an angle of $90^{0}$. The electron recoils and moves in another direction. The compton wavelength is $(h=6.62 \times 10^{-34}Js.)$

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

  1. $0.121\times 10^{-11}m$

  2. $0.486\times 10^{-11}m$

  3. $2.4\times 10^{-11}m$

  4. $0.243\times 10^{-11}m$

Show answer
Correct Option: D
Explanation:

Compton wavalength $=\dfrac{h}{m _{e}c}(1-cos\theta )$


                             $=\dfrac{6.62\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}(1-cos\ 90^{0})$

                             $=0.243\times 10^{-11}(1-0)\ ( \because cos\ 90^{0}=0)$
                            $=0.243\times 10^{-11}m$
So, the answer is option (D).

The wavelength of scattered radiation when it undergoes compton scattering at an angle of $60^o$ by graphite is $2.54 \times 10^{-11}$m, then the wavelength of incident photon is

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

  1. $4.2\times 10^{-11}m$

  2. $1.12\times 10^{-11}m$

  3. $1.21\times 10^{-11}m$

  4. $2.42\times 10^{-11}m$

Show answer
Correct Option: D
Explanation:

Compton formula
$\Delta \lambda = \lambda _f-\lambda _i= \dfrac{h}{m _ec}  (1- cos  \theta )$


$2.54\times 10^{-11}-\lambda _1= \dfrac{6.63\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^8}  \big(1- cos  60^{\circ }\big)$

$\lambda _i= 2.54\times 10^{-11}
- \dfrac{6.63\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^8}  \big(1- 1/2 \big) \ \ \ \  \big(\because cos  60^{\circ} =  1/2\big)$

$= 2.54\times 10^{-11}-0.12\times 10^{-11}$
$=2.42\times 10^{-11}m$
So, the answer is option (D).

In a Compton effect experiment, the wavelength of incident photons is 3$A^{0}$.If the incident radiation is scattered through $60^{0}$ , the wavelength of scattered radiation is nearly (given$h=6.62\times 10^{-34}Js$, $m _{o} = 9.1 \times 0^{-31}$ kg, $c = 3 \times 10^{8}$ m/s)

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

  1. 3.024 $A^{0}$

  2. 3.012 $A^{0}$

  3. 3.048$A^{0}$

  4. 2.988 $A^{0}$

Show answer
Correct Option: B
Explanation:

${\lambda }'-\lambda =\dfrac{h}{m _{e}c}(1-cos\theta)$


${\lambda }'=\lambda +\dfrac{6.62\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}(1-cos60^{\bullet})$

$=\lambda +0.0121\ A^{0}$
$=3A^{\bullet}+0.0121$
$=3.012\ A^{\bullet }$
So, the answer is option (B).

The maximum increase in X-ray wavelength that can occur during Compton scattering is

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

  1. $5.84\times 10^{-12}m$

  2. $6.84\times 10^{-3}m$

  3. $7.84\times 10^{-10}m$

  4. $4.84\times 10^{-12}m$

Show answer
Correct Option: D
Explanation:

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

For maximum increase $ cos\theta =   -1$

so $\Delta \lambda =  \dfrac{h}{m _{e}C} (1-(-1))$

$=  \dfrac{2h}{m _{e}C}$

$=  \dfrac{2\times 6.63\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}$

$=  0.484 \times 10^{-11}m$
$=  4.84 \times 10^{-12}m$

So, the answer is option (D).

X-rays of 1.0$A^{0}$ are scattered from a carbon block. The wavelength of the scattered beam in a direction making $90^{0}$ with the incident beam is

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

  1. 1.024$A^{0}$

  2. 2.024$A^{0}$

  3. 3.024$A^{0}$

  4. 4.024$A^{0}$

Show answer
Correct Option: A
Explanation:

Compton effect formula

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

$\lambda _{f}-1.0 A^{\circ} = \dfrac{6.63\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}\ (1-cos  90^{\circ})$

$\lambda _{f} = 1  A^{\circ}+ \dfrac{6.63\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}  (1-0)$             $(\because  cos  90^{\circ}=0)$

$= 1  A^{\circ}+  0.24 \times 10^{-11}m$
$= 1  A^{\circ}+  0.024  A^{\circ}   (\because  10^{-10}m= 1  A^{\circ})$
$= 1.024  A^{\circ}$

So, the answer is option (A).

A photon recoils back after striking a free electron. Then the value of compton shift is

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

  1. 0.0242 $A^{0}$

  2. 0.0484 $A^{0}$

  3. 0.0121 $A^{0}$

  4. 0.242 $A^{0}$

Show answer
Correct Option: B
Explanation:

$\lambda -\lambda \ '=\dfrac{h}{m _{e}c}(1-cos\theta )$


$\Delta \lambda =\dfrac{6.62\times 10^{-34}}{9.1\times 10^{-31}\times 3\times 10^{8}}(1-cos180)$

$=0.0484\ A^{0}$
So, the answer is option (B).

Which waves are used in sonography?

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

  1. Microwaves

  2. Infrared rays

  3. Radio rays

  4. Ultrasonic rays

Show answer
Correct Option: D
Explanation:
Ultrasound imaging is also termed as the ultrasound scanning or sonography, This technique uses the small probe along with the gel placed on the skin. The sound waves of very high frequency (Ultrasonic sound) are sent into the body via gel using the probes to obtain the images of body parts.

Therefore, the sonography or ultrasonic scanning uses the Ultrasonic rays.

When X-rays or gamma rays interact with matter, there is a decrease in the energy of the X-rays or gamma rays. This is known as the ____________.

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

  1. photoelectric effect

  2. Raman effect

  3. Compton effect

  4. none of these

Show answer
Correct Option: C
Explanation:

Compton effect

When a light wave (Photon) is incident on an electron, there is a decrease in energy of a photon as a part of its initial energy is transferred to the electron which is scattered. This effect is called Compton effect.


The $X-$ray beam emerging from an $X-$ray tube

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

  1. is monochromatic

  2. contains all wavelength smaller than a certain maximum wavelength

  3. contains all wave length larger than a certain minimum wavelength

  4. contains all wave length lying between a minimum and a maximum wavelength

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Correct Option: C

Two open pipes of length $20$ cm and $20.1$ cm produces $10$ beats/s. The velocity of sound in the gas is 

speed of sound in gas speed of a travelling wave oscillation and waves waves physics

  1. $804 ms^{-1}$

  2. $402 ms^{-1}$

  3. $420 ms^{-1}$

  4. $330 ms^{-1}$

Show answer
Correct Option: B