Tag: units and measurements

Questions Related to units and measurements

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

The volume of a sphere is $ 1.76\;{cm }^{ 3 }$. The volume of 25 such spheres according to the idea of significant figures in ${cm}^{ 3 }$ is 

  1. 44.00

  2. 44.0

  3. 44

  4. 4.4

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Volume of 1 sphere $=1.76 cm^{3}$
Volume of 25 spheres $=25\times 1.76$
                                      $=44 {cm}^{3}$
                                      $=44.0 {cm}^{3}$
                                 (Since volume is reported in 3 significant figure)

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

A body of mass $m =3.513\ kg$ is moving along the x-axis with a speed of $5.00{ ms }^{ -1 }$. The magnitude of its momentum is recorded as :

  1. $17.56\ kg{ ms }^{ -1 }$

  2. $17.57\ kg{ ms }^{ -1 }$

  3. $17.6\ kg{ ms }^{ -1 }$

  4. $17.565\ kg{ ms }^{ -1 }$

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Momentum$=mv=3.513\times 5.00=17.565\approx 17.57$
$\approx 17.6 kg m/s$
(Since 5.00 contains  least no. of significant figures i.e. 3)

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

A student measure the thickness of an object by three different instruments and gets the result as 0.5 cm, 0.50 cm, 0.500 cm. State the one which is more accurate. 

  1. $0.5$ cm

  2. $0.50$ cm

  3. $0.500$ cm

  4. All the measurements are equally accurate.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Since, the measurement $0.500 \ cm$ gives the reading up to 3 decimel, thus $0.500 \ cm$ is the most accurate measurement among the given three measurements.

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

In the number 2.4560, there are 5 significant digits. Which one is the least significant digit?

  1. 2

  2. 4

  3. 0

  4. 6

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The least significant digit is the lowest digit in a number, located at the far right of a string.


Here 0 is the rightmost side of this number so this is least significant digit.


Option C is the correct answer