Tag: physics

Questions Related to physics

______________are the result of exploding stars that initially are more than about eight times the sun's mass.

physics life cycle of stars evolution and end stages of stars the stars stars

  1.  stars

  2. black hole

  3. supernova

  4. none of these

Show answer
Correct Option: C

Which of the following is the stage where a massive star explodes and releases a lot of energy?

physics life cycle of stars evolution and end stages of stars the stars stars

  1. Red supergiant

  2. Blackhole

  3. Main sequence

  4. Supernova

Show answer
Correct Option: B
Explanation:

Stars with very large masses can become black holes. A black hole releases a huge amount of gravitational energy, as material swirls toward its event horizon. This energy produces a jet of particles that streams over a distance of 300,000 light-years.

The constellation of stars appear at different positions in the sky at different times during night mainly ________________________.

physics life cycle of stars evolution and end stages of stars the stars stars

  1. Because earth rotates about its axis

  2. Because Earth revolves round the sun

  3. Because of optical illusion

  4. Because celestial bodies are changing their positions all the time

Show answer
Correct Option: A

The sounds having frequency less than 20 Hz are called ultrasonics.

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear.

so the answer is B.

Human ears can sense sound wave travelling in air having wavelength of ................... .

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. $10^{-3}$ m

  2. $10^{-2}$ m

  3. 1 m

  4. $10^{2}$ m

Show answer
Correct Option: C
Explanation:

The audible wave length range of human beings in (16.5 mm - 16.5 m)
Hence 1 m is the correct option.

The frequencies below 20 Hz are known as infrasonic sounds.

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

yes , below 20hz frequency sound is infrasonic.

so the answer is A.

What is the approximate range of audible sound frequencies for a human with good hearing?

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. From $20Hz$ to $2000Hz$

  2. From $20Hz$ to $20000Hz$

  3. From $200Hz$ to $20000Hz$

  4. From $200Hz$ to $200000Hz$

Show answer
Correct Option: B
Explanation:

Adult humans can hear from 20Hz to 20000Hz of frequency.

Which of the following frequencies of sound elephants produce ?

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. ultrasonic

  2. infrasonic

  3. both A & B

  4. cant say

Show answer
Correct Option: B
Explanation:

Some of the elephant's vocalizations are infrasonic, and thus are inaudible to humans. The prominence of very low frequencies in the vocalizations is a defining characteristic of all three species of elephants. Sounds are generally considered to be infrasonic if their frequency is less than $20 Hz$ (the lower limit of human hearing). Low frequency sounds travel farther than high frequency ones, which make them ideal for long distance communication.
Hence, Elephants produce infrasonic sound. 

Name the sounds of the frequencies given below $10Hz$.

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. $ultrasonic$

  2. $infrasonic$

  3. $supersonic$

  4. None of the above

Show answer
Correct Option: B
Explanation:

Infra-sound is a low-frequency sound. It is sound that is lower in frequency than $20 \ Hz$ or cycles per second, the normal limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing infra-sound, but at higher intensities it is possible to feel infra-sound vibrations in various parts of the body.

Infrasound can be heard by

physics sound audible, infrasonic and ultrasonic sounds different sounds range of hearing

  1. dog

  2. bat

  3. rhinoceros

  4. human beings

Show answer
Correct Option: C
Explanation:

Rhinos have extremely good ears, picking up infra-sound far deeper than the range of human hearing.
Rhinos, can hear down to a frequency of four hertz, whereas even a human baby, with entirely undamaged ears, can normally only pick up sounds as low as 20 hertz. Giraffes and elephants can also hear in this infra-sound range.