Tag: physics

Questions Related to physics

The amount of substance in the SI system of units is represented by 

physics measurements and units summary of si units fundamental quantities system of units

  1. Candela

  2. Mole

  3. Weight

  4. Kilogram

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Correct Option: B
Explanation:

Mole represents the amount of substance in the SI system of units.

The SI unit of temperature is

physics measurements and units summary of si units fundamental quantities system of units

  1. Kelvin

  2. Second

  3. Mole

  4. Candela

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Correct Option: A
Explanation:

SI unit of temperature is Kelvin denoted by  $K$.

$\displaystyle N{ kg }^{ -1 }$ is the unit of 

physics measurements and units summary of si units fundamental quantities system of units

  1. Retardation

  2. Acceleration

  3. Rate of change of velocity

  4. All of these

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Correct Option: D
Explanation:
Acceleration is measured as   $a = \dfrac{Force}{mass}$

Thus, $N kg^{-1}$ is the unit of acceleration.

Retardation is the acceleration in the opposite direction.

Also, acceleration is defined as rate of change of velocity of the body.
Thus option D is correct.

Unit for the rate of change of velocity is 

physics measurements and units summary of si units fundamental quantities system of units

  1. $\displaystyle m/s$

  2. $\displaystyle { m }/{ { s }^{ 2 } }$

  3. $\displaystyle Ns$

  4. $\displaystyle N/s$

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Correct Option: B
Explanation:
Rate of change of velocity is known as acceleration.
Unit of acceleration is  $m/s^2$

Kilowatt hour $\left(kWh\right)$ represents the unit of

physics measurements and units summary of si units fundamental quantities system of units

  1. Power

  2. Impulse

  3. Momentum

  4. Energy

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Correct Option: D
Explanation:
Kilowatt hour $(kWh)$ is the unit of energy.
$1 \ kWh = 3.6\times 10^6 \ J$

Which of the following physical quantities has no unit?

physics measurements and units summary of si units fundamental quantities system of units

  1. Relative density

  2. Density

  3. Pressure

  4. Thrust

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Correct Option: A
Explanation:
Relative density is defined as the ratio of density of a given substance to the density of water.
Thus relative density has no unit.

Milligram is a submultiple of kilogram.

physics measurements and units summary of si units fundamental quantities system of units

  1. True

  2. False

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Correct Option: A
Explanation:

Milligram is a submultiple of Kilogram.

Which is measured in hertz?  

physics measurements and units summary of si units fundamental quantities system of units

  1. Frequency

  2. Amplitude

  3. Period

  4. Wavelength

  5. Kinetic Energy

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Correct Option: A
Explanation:

Frequency of a wave is measured in hertz  $(Hz)$.

Parallactic second is a unit of :

physics measurements and units summary of si units fundamental quantities system of units

  1. Time

  2. Speed

  3. Distance

  4. None of these

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Correct Option: C
Explanation:

Parallactic second is a unit of distance.

Light year is the unit of time.

physics measurements and units summary of si units fundamental quantities system of units

  1. True

  2. False

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Correct Option: B
Explanation:
One light year is defined as the distance travelled by light in vacuum on one year. So light year is the unit of distance.
So, the given statement is false.