Tag: motion and measurement

Questions Related to motion and measurement

65 mm is equivalent of approximately:

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. 1.5 inches

  2. 3.5 inches

  3. 2.6 inches

  4. 10.5 inches

Show answer
Correct Option: C
Explanation:

We know that $1 \ mm = 0.039 \ inch$ 


So  $65 \ mm = 65 \ mm\times \dfrac{0.039 \ inch}{1 \ mm} = 2.6 \ inches$

What is number of significant figures in $0.310\times 103$ ?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. 2

  2. 3

  3. 4

  4. 6

Show answer
Correct Option: B
Explanation:

Since the numbers $0.310$ and $103$ have 3 significant figures each. In the case of the multiplication, the maximum number of significant figures is the same as that of the number of significant figures in decimal number., so the final answer must also have 3 significant figures.

One Femto is equal to :

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. ${10^{15}}$

  2. ${10^{-15}}$

  3. ${10^{-12}}$

  4. ${10^{-10}}$

Show answer
Correct Option: B
Explanation:
One Femto is a very small unit.
$1$ Femto $ = 10^{-15}$

SI unit of Angle is Steradian?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The steradian (symbol: sr) or square radian is the S.I. unit of solid angle. It is used in three-dimensional geometry, and is analogous to the radian, which quantifies planer angles.

Pascal is unit of which of the following quantity?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. Temperature

  2. Pressure

  3. Force

  4. Impulse

Show answer
Correct Option: B
Explanation:

Pressure is measured in Pascal $(Pa)$.

Which of the two have same dimensions ?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. Force & Strain

  2. Angular velocity & Angular Frequency

  3. Force & Stress

  4. None of the above

Show answer
Correct Option: B
Explanation:

Angular velocity and angular frequency have the same dimension  $[T^{-1}]$.

Which of the following pairs of physical quantities have same dimensions?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. Force and power

  2. Torque and energy

  3. Torque and power

  4. Force and torque

Show answer
Correct Option: B
Explanation:
Torque is the moment of force given by:$ \vec\tau=\vec r\times \vec F$

It’s unit is Newton-meter.

The unit of work/energy is also Newton-meter or Joule.

Thus, both of these physical quantities have the same units/dimensions.

$[Torque]=[M][L]^{2}[T]^{−2}=[Energy]$

Which one of the following is not a derived unit?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. joule

  2. watt

  3. kilogram

  4. newton

Show answer
Correct Option: C
Explanation:

Among the given units kilogram is the fundamental or base unit whereas others are the derived units.

Which of the following statements is incorrect regarding mass. ?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. It is a basic property of matter.

  2. The SI unit of mass is kg.

  3. The mass of an atom is expressed in u.

  4. It depends upon the temperature, pressure or location of the object in space.

Show answer
Correct Option: D
Explanation:

Mass is property of mater, which is independent of other properties like temperature, pressure or location of the object in space.

Which of the following is unitless quantity?

physics motion and measurement physical quantities units - definitions and systems physical quantities like mass and weight

  1. Pressure gradient

  2. Displacement gradient

  3. Force gradient

  4. Velocity gradient

Show answer
Correct Option: B
Explanation:

The gradient of any physical quantity is computed to as per unit length. This means it is a rate with respect to length. So, the Displacement gradient will also be length per unit length. Because a displacement gradient is the ratio of two quantities having dimensions of "length". That is, a displacement gradient has units of a meter per meter for example. 

The length dimensions will be cancelled, and we have a unitless quantity. While others will be having certain units. Hence it is a unitless quantity.

Thus option B is correct.