Tag: physics

Questions Related to physics

The planets revolve round the sun in _______ orbits.

physics our solar system planets of the solar system solar system and sun introduction to solar system

  1. circular

  2. spiral

  3. elliptical

  4. helical

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Correct Option: C
Explanation:

Ans: Elliptical 

The difference in the length of a mean solar day and a sidereal day is about

physics our solar system planets of the solar system solar system and sun introduction to solar system

  1. $1$ minute

  2. $4$ minute

  3. $15$ minute

  4. $56$ minute

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Correct Option: B
Explanation:

Solar day is the time taken by earth to complete one rotation about its axis with respect to sun. Sidereal day is the time taken by earth to complete one rotation about its axis with respect to distant star. There is a difference of $4$ minutes between solar day and sidereal day. Solar day is longer as earth has to rotate greater angle to attain same position with respect to sun due to its own motion (revolution) round the sun. Its position with respect to distant star remains almost fixed.

If the axis of rotation of the earth were extended into space then it would pass close to

physics our solar system planets of the solar system solar system and sun introduction to solar system

  1. The moon

  2. The sun

  3. The polar star

  4. The centre of mass of all the planets in the solar system

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Correct Option: C
Explanation:

A pole star is a visible star, which lies approximately directly overhead when viewed from earth's north pole or south pole. In practice the term pole star usually refers to polars, which is the current northern pole star, also known as north star. The south celestial pole lacks a bright star like polarise to mark its position.

Which of the following describes ecliptic orbit?

physics our solar system planets of the solar system solar system and sun introduction to solar system

  1. Orbit travelled by the Moon round the Sun.

  2. Path travelled by the Earth round the Sun

  3. Orbit along which Sun appears to move among the stars

  4. Orbit along which Moon appears to move among the stars

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Correct Option: C
Explanation:
An ecliptic orbit is the one, in which the Sun appears to move among all the stars.

Who was the first to suggest, "A planet moves most quickly when it is closest to the sun, but slows down as it moves farther away"?

physics our solar system planets of the solar system solar system and sun introduction to solar system

  1. Johannes Kepler

  2. Galileo Galilei

  3. Tycho Brahe

  4. Edwin Hubble

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Correct Option: A
Explanation:

Kepler's law states that a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time. So a planet moves most quickly when it is closest to the sun,as it have to cover more distance in same time but it again  slows down as it moves farther away as covering distance is less.

The balls of a walleye or sample are made of large size. It is of for 

intensity and loudness waves physics

  1. Producing sound of higher pitch

  2. Producing bond sound

  3. Producing sound of higher quality

  4. Decreasing purpose

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Correct Option: A

The power of sound from speaker of radio is 10 W, the power of sound from the speaker of radio is 400 W by increasing the volume of radio. The power increased in dB as compared to original power is nearly

intensity and loudness waves physics

  1. 8

  2. 12

  3. 13

  4. 16

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Correct Option: D

State the factors that determine the loudness of the sound heard.

intensity and loudness waves physics

  1. Amplitude

  2. Freqency

  3. Time period

  4. Pitch

Show answer
Correct Option: A
Explanation:

Amplitude is the size of the vibration, and this determines how loud the sound is Larger vibrations make a louder sound.The intensity or loudness of a sound depends upon the extent to which the sounding body vibrates, i.e., the amplitude of vibration. A sound is louder as the amplitude of vibration is greater, and the intensity decreases as the distance from the source increases. Hence, loudness is dependent on amplitude.

Name the characteristic of the sound affected due to a change in its amplitude.

intensity and loudness waves physics

  1. Loudness.

  2. Wavelength.

  3. Frequency.

  4. Waveform.

Show answer
Correct Option: A
Explanation:

Amplitude is the size of the vibration, and this determines how loud the sound is.  Larger vibrations make a louder sound.
The intensity or loudness of a sound depends upon the extent to which the sounding body vibrates, i.e., the amplitude of vibration. A sound is louder as the amplitude of vibration is greater, and the intensity decreases as the distance from the source increases.
Hence, loudness of the sound is affected due to the change in its amplitude.

As we move away from the source along with the amplitude which of the following quantity decreases as well ?

intensity and loudness waves physics

  1. waveform

  2. loudness

  3. wavelength

  4. intensity

Show answer
Correct Option: B
Explanation:

The intensity or loudness of a sound depends upon the extent to which the sounding body vibrates, i.e., the amplitude of vibration. A sound is louder as the amplitude of vibration is greater, and the intensity decreases as the distance from the source increases. Loudness is measured in units called decibels. 
Loudness depends on the square of the amplitude of the wave. That is, $loudness{ \propto \left( amplitude \right)  }^{ 2 }$.
Hence, As it moves away from the source its amplitude as well as its loudness decreases.