Tag: units - definitions and systems

Questions Related to units - definitions and systems

State whether true or false.
The measure of an angle is dependent upon the unit of length.

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

  1. True

  2. False

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Correct Option: A
Explanation:
Plane angle is defined as the ratio of arc length to the radius.
Plane angle   $\theta = \dfrac{l}{r}$
So, the measure of an angle is dependent upon the unit of length. Thus, the given statement is true.

Which of the following unit is different from other:

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

  1. Electron volt

  2. Kilo Watt hour

  3. Watt sec

  4. Volt

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Correct Option: D
Explanation:
Electron volt, kilo Watt hour and Watt sec are the units of energy but volt is the unit of potential difference (or voltage).
Thus volt is odd one out here.

$Weber/{m^2}$ = 

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

  1. Tesla

  2. Dyne

  3. Watt

  4. Henry

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Correct Option: A
Explanation:
$Weber/m^2$ is the S.I. unit of magnetic field strength. Magnetic field is also measured in another SI unit $Tesla$.
$Weber/m^2 = Tesla$

1 Nanometer = ?

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

  1. ${10^{-3}}m$

  2. ${10^{-6}}m$

  3. ${10^{-9}}m$

  4. ${10^{-12}}m$

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Correct Option: C
Explanation:
According to the standard conversions,  $1 \ nm = 10^{-9}\ m$
One nanometer is vary small unit. of distance.

Accuracy of a measurement is determined by :

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

  1. Absolute

  2. Percentage

  3. Both

  4. None of these

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Correct Option: B
Explanation:

Percentage determines the accuracy in the measurement. More is the percentage of error, more is the error in the 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

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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

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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. ${10^{-10}}$

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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

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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

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Correct Option: B
Explanation:

Pressure is measured in Pascal $(Pa)$.