Tag: physics

Questions Related to physics

State whether the given statement is True or False :

Humans can neither hear infrasonic nor ultrasonic sounds. 

physics medical imaging ultrasonic sound using ultrasound in medicine ultrasound and its applications

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Audible range of frequency for human ear is  $20 \ Hz$ to $20 \ kHz$. Humans cannot hear sounds having frequency other than this range.
Sounds having frequency lower than $20 \ Hz$ are known as infrasonic sounds and that having frequency greater than $20 \ kHz$ are known as ultrasonic sounds. Thus, humans can neither hear infrasonic nor ultrasonic sounds.

State whether given statement is True or False :
Aquatic animals as dolphins also use ultrasound to catch their prey.

physics medical imaging ultrasonic sound using ultrasound in medicine ultrasound and its applications

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Aquatic animals as dolphins also use ultrasound to catch their prey. Statement is true.

Which of the following are applications of ultrasound.

physics medical imaging ultrasonic sound using ultrasound in medicine ultrasound and its applications

  1. Ultrasound has been used in a variety of clinical settings, including obstetrics and gynecology, cardiology and cancer detection.

  2. Ultrasound is well known to have a significant effect on the rate of various processes in the food industry.

  3. Ultrasound is used in the synthesis of nanostructured materials.

  4. All of these.

Show answer
Correct Option: D
Explanation:

The options in the question are given unnecessarily. It can be a direct question.
Below are the applications of ultrasound.

  • Ultrasound has been used in a variety of clinical settings, including obstetrics and gynecology, cardiology and cancer detection. The main advantage of ultrasound is that certain structures can be observed without using radiation. Ultrasound can also be done much faster than X-rays or other radiographic techniques. 
  • Ultrasound is well known to have a significant effect on the rate of various processes in the food industry. Using ultrasound, full reproducible food processes can now be completed in seconds or minutes with high reproducibility, reducing the processing cost, simplifying manipulation and work-up, giving higher purity of the final product, eliminating post-treatment of waste water and consuming only a fraction of the time and energy normally needed for conventional processes. Several processes such as freezing, cutting, drying, tempering, bleaching, sterilization, and extraction have been applied efficiently in the food industry. The advantages of using ultrasound for food processing, includes: more effective mixing and micro-mixing, faster energy and mass transfer, reduced thermal and concentration gradients, reduced temperature, selective extraction, reduced equipment size, faster response to process extraction control, faster start-up, increased production, and elimination of process steps. Food processes performed under the action of ultrasound are believed to be affected in part by cavitation phenomena and mass transfer enhancement. 
  • Ultrasound is used in the synthesis of nanostructured materials.
  • Devices limited to low ultrasonic frequencies, have a number of industrial applications, including drying, ultrasonic cleaning, and injection of fuel oil into burners. 

Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heared by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospital to break kidney stones of a patient into fine grains which then get flushed out with Urine. The sound similar to that which is produced during an earthquake before the main shock wave is generated.Name one device in our homes
which can produce sound like Z.

physics medical imaging ultrasonic sound using ultrasound in medicine ultrasound and its applications

  1. oven

  2. Doorbell

  3. no such device is there in our homes

  4. all devices produce such sound

Show answer
Correct Option: B
Explanation:

ultrasound is used for removing kidney stones.when ultrasound are targeted on such stone,the stones start vibrating at high frequency.the stone due to this vibratory motion. Breakdown into fine particles.ultrasounds and infrasounds are not audible to man.ultrasound have frequency more than 20kHz.a doorbell can produce an audible sound. Infrasound have frequency below 20Hz, X is ultrasound. Y is infrasound, Z is audible sound.

Rats also play games by producing -------

physics medical imaging ultrasonic sound using ultrasound in medicine ultrasound and its applications

  1. ultrasound

  2. infrasound

  3. audible sound

  4. all

Show answer
Correct Option: A
Explanation:

Frequencies higher than 20 kHz are called ultrasonic sound
or ultrasound. Ultrasound is produced by dolphins, bats and porpoises. Moths of certain families have very sensitive hearing equipment. These moths can hear the high frequency squeaks of the bat and know when a bat is flying nearby, and are able to escape capture. Rats also play games by producing ultrasound.

Frequency of Ultrasonic waves is .................

physics medical imaging ultrasonic sound using ultrasound in medicine ultrasound and its applications

  1. less than $20,000 Hz$

  2. greater than $20,000 Hz$

  3. Less than $20 Hz$

  4. $1000 Hz$

Show answer
Correct Option: B
Explanation:

having a frequency above the human ear's audibility limit of about 20,000 hertz —used of waves and vibrations

Three right angied prisms of refractive indices $\mu _1$,$\mu _2$ and $\mu _3$ are joined together so that the faces of the middle prism are each in contact with one the outside prism.If the ray passes through the composite block undeviated,then

problems on prism prism ray optics and optical instruments optics physics

  1. ${\mu _1}^2+{\mu _3}^2-{\mu _2}^2 = 1$

  2. ${\mu _1}^2-{\mu _3}^2+{\mu _2}^2 = 1$

  3. ${\mu _1}^2-{\mu _3}^2-{\mu _2}^2 = 1$

  4. ${\mu _2}^2+{\mu _3}^2-{\mu _1}^2 = 1$

Show answer
Correct Option: A

Total reflecting prisms are _____ prism.

problems on prism prism ray optics and optical instruments optics physics

  1. Right angled

  2. Acute angled isosceles

  3. Right angled isosceles

  4. Obtuse angled isosceles.

Show answer
Correct Option: C
Explanation:

Total reflecting prism are right angled isosceles prism with $90^{o}$ between two refracting surfaces.

An equilateral prism deviates a ray through $45^{\circ}$ for the two angles of incidence differing by $20^{\circ}.$ The angle of incidence is

problems on prism prism ray optics and optical instruments optics physics

  1. $62.5^{\circ}$

  2. $42.5^{\circ}$

  3. Both are correct

  4. Both are wrong

Show answer
Correct Option: C
Explanation:

First angle of incidence $=i _1=i$

Second angle of incidence $i _2=i _1+20^\circ$
Angle of deviation, $d=i _1+i _2-A$ where A is angle of prism.
$45=2i+20-60$
$i=42.5$
$i _2=i+20=62.5$
Hence both are correct.

A light ray is incident normally on one of the refracting faces of a prism and just emerges  out grazing the second surface. The relation between angle of the prism and its critical angle is

problems on prism prism ray optics and optical instruments optics physics

  1. $A=C$

  2. $A\neq C$

  3. $A< C$

  4. $A>C$

Show answer
Correct Option: D