Tag: standardized measurement

Questions Related to standardized measurement

Which of the following is different from others?

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1. Speed

  2. Density

  3. Force

  4. Time

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Correct Option: D
Explanation:

Speed, density and force are the derived physical quantities whereas time is the fundamental physical quantity.

Mass is a _________ physical quantity.

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1. derived

  2. fundamental

  3. semi-derived

  4. valueless

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Correct Option: B
Explanation:

There are only $7$ fundamental physical quantity out of which mass is a fundamental quantity.

Which of the following physical quantity is different form others ?

physics measurements and units kinds of units fundamental quantities standardized measurement

  1. Displacement

  2. Velocity

  3. Force

  4. Kinetic energy

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Correct Option: D
Explanation:

Displacement, force, and velocity are vector quantities as they require direction as well as the magnitude for their representation but the kinetic energy is a scalar quantity as it does not require direction for its representation.

Write the SI unit of the physical quantity having following dimensional formula
$\displaystyle [{ M }^{ 0 }{ L }^{ 2 }{ T }^{ -2 }{ K }^{ -1 }]$.

physics measurements and units kinds of units fundamental quantities standardized measurement

  1. $\displaystyle {m} { kg }^{ 2 }{ K }^{ -1 }$

  2. $\displaystyle {m} ^{2} { kg }^{ 2 }{ T }^{ -1 }$

  3. $\displaystyle {m} ^{2} { s }^{ -2 }{ K }^{ -1 }$

  4. $\displaystyle {m} ^{2} { kg }^{ 2 }{ K }^{ -1 }$

Show answer
Correct Option: C
Explanation:
SI unit of $M$ is $kg$, that of $L$ is $m$, $T$ is $s$ and temperature (K) is $K$.

So, SI unit of $[M^0L^2T^{-2}K^{-1}]$ is  $m^2s^{-2}K^{-1}$.

Dimensional analysis is the analysis of the relationships between different physical quantities by 

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1.  identifying their fundamental dimensions

  2. units of measure

  3. tracking these dimensions as calculations or comparisons are performed.

  4. All of the above 

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Correct Option: D
Explanation:

Dimensional analysis establishes the relation between the physical quantities by comparing the different quantities using their fundamental dimensions.

The dimensional analysis also makes use of the units to measure different quantities and the dimensional analysis is also helpful in performing several calculations.

State whether true or false.
The mass of a body can never be zero.

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1. True

  2. False

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Correct Option: A
Explanation:
Mass of a body is defined as the quantity of matter contained in it. Since, all bodies are made up of certain matter. Thus mass of body can never be zero.

Which one of the following is not a fundamental SI unit?

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1. Ampere

  2. Candela

  3. Newton

  4. Kelvin

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Correct Option: C
Explanation:

F = ma = kgms-2

SI unit of force is Newton(W)

Hence, newton is a derived unit

A dimensionless quantity

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1. never has a unit

  2. always has unit

  3. may have a unit

  4. does not exit

Show answer
Correct Option: C
Explanation:

A dimensionless quantity is that is always independent of basic $7$ units:-meter, second, kilogram, Kelvin, Candela, ampere.

But it is not necessary. A dimensionless quantity is unitless. And eg, for this, is radian (unit of angle), which is dimensionless quantity because it is the ratio of two lengths.

Some physical quantities are given in Column I and some possible SI units in which these quantities may be expressed are given in Column II. Match the physical quantities in Column I with the units in Column II.

Column I Column II
i. $GM _eM _s$ a. (volt) (coulomb) (metre)
ii. $3RT/M$ b. $(kilogram)(metre)^3 (second)^2$
iii. $F^2/q^2B^2$ c. $(meter)^2 (second)^{-2}$
iv. $GM _e/R _e$ d. $(farad) (volt)^2 (kg)^{-1}$


where G is universal gravitational constant; $M _e$ mass of the earth; $M _s$, mass of sun; $R _e$ radius of the earth; R, universal gas constant;T, absolute temperature; M, molar mass, F, force; q, charge; B, magnetic field.

physics measurements and units kinds of units fundamental quantities standardized measurement

  1. $i \rightarrow b., ii \rightarrow c.,d., iii \rightarrow c.,d., iv \rightarrow c.,d.,$

  2. $i \rightarrow a., ii \rightarrow c.,d., iii \rightarrow c.,d., iv \rightarrow c.,d.,$

  3. $i \rightarrow d., ii \rightarrow c.,d., iii \rightarrow c.,d., iv \rightarrow c.,d.,$

  4. $i \rightarrow c., ii \rightarrow c.,b., iii \rightarrow c.,d., iv \rightarrow c.,d.,$

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Correct Option: B

Pressure (P), density $\displaystyle (\rho )$ and velocity (V) be taken as fundamental quantities for dimensional analysis.

physics measurement of physical quantities kinds of units fundamental quantities standardized measurement

  1. True

  2. False

Show answer
Correct Option: B
Explanation:
Pressure is calculated as   $P = \dfrac{Force}{Area}$
Density  $\rho = \dfrac{Mass}{Volume}$

Velocity  $V = \dfrac{Displacement}{time}$

So, pressure, density and velocity are derived from other quantities and so, these are termed as derived quantities , not fundamental quantities.
Hence, the given statement is false.