Tag: measurements and units

Quizzes (10) Questions (257)

Questions Related to measurements and units

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

Consider the following two statements A and B and identify the correct answer.
A) The size ($u$) of the unit of physical quantity and its numerical magnitude ($n$) are related to each other by the relation nu $=$ constant
B) The choice of mass, length and time as fundamental quantities is not unique.

  1. A is true but B is false

  2. B is true but A is false

  3. Both A and B are true

  4. Both A and B are false
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A: eg. $10$ seconds, where $n=10, u=$seconds. This is constant.
B: We can choose any quantity as fundamental and derive other quantities with respect to that

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

Debye is a unit of

  1. rms velocity

  2. force

  3. specific gravity

  4. electric dipole moment
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The correct option is D.

The Debye, represented as D, is a CGS unit of electric dipole moment. This name was given in the honor of the physicist Peter J. W. Debye. Its value is defined as $1 \times { 10 } ^{ -18 }$ statcoulomb-centimetre.

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

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

  1. Retardation

  2. Acceleration

  3. Rate of change of velocity

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
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.