Tag: summary of si units

Questions Related to summary of si units

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

  1. Candela

  2. Mole

  3. Weight

  4. Kilogram


Correct Option: B
Explanation:

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

The SI unit of temperature is

  1. Kelvin

  2. Second

  3. Mole

  4. Candela


Correct Option: A
Explanation:

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

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

  1. Retardation

  2. Acceleration

  3. Rate of change of velocity

  4. All of these


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 

  1. $\displaystyle m/s$

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

  3. $\displaystyle Ns$

  4. $\displaystyle N/s$


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

  1. Power

  2. Impulse

  3. Momentum

  4. Energy


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?

  1. Relative density

  2. Density

  3. Pressure

  4. Thrust


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.

  1. True

  2. False


Correct Option: A
Explanation:

Milligram is a submultiple of Kilogram.

Which is measured in hertz?  

  1. Frequency

  2. Amplitude

  3. Period

  4. Wavelength

  5. Kinetic Energy


Correct Option: A
Explanation:

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

Parallactic second is a unit of :

  1. Time

  2. Speed

  3. Distance

  4. None of these


Correct Option: C
Explanation:

Parallactic second is a unit of distance.

Light year is the unit of time.

  1. True

  2. False


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.