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

State whether the given statement is True or False :

Humans can neither hear infrasonic nor ultrasonic sounds. 

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

Which of the following are applications of ultrasound.

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

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

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.

  1. oven

  2. Doorbell

  3. no such device is there in our homes

  4. all devices produce such sound
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

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

  1. ultrasound

  2. infrasound

  3. audible sound

  4. all
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

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

  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. ${\mu _2}^2+{\mu _3}^2-{\mu _1}^2 = 1$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For a ray to pass through a composite block of three prisms undeviated, the net deviation must be zero. This condition leads to the relationship between the refractive indices of the prisms.

Multiple choice problems on prism prism ray optics and optical instruments optics physics

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

  1. $62.5^{\circ}$

  2. $42.5^{\circ}$

  3. Both are correct

  4. Both are wrong
Reveal answer Fill a bubble to check yourself
C Correct answer
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.