Physical World Units and Measurements - Result Question 2

«««< HEAD:content/english/neet-pyq-chapterwise/physics/physical-world-units-and-measurements/physical-world-units-and-measurements-result-question-2.md

2. The density of material in CGS system of units is $4 g / cm^{3}$. In a system of units in which unit of length is $10 cm$ and unit of mass is $100 g$, the value of density of material will be [2011M]

======= ####2. The density of material in CGS system of units is $4 g / cm^{3}$. In a system of units in which unit of length is $10 cm$ and unit of mass is $100 g$, the value of density of material will be [2011M]

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/physical-world-units-and-measurements/physical-world-units-and-measurements—result-question-2.md (a) 0.4

(b) 40

(c) 400

(d) 0.04

Show Answer

Answer:

Correct Answer: 2. (b)

Solution:

  1. (b) In CGS system, density $d=4 \frac{g}{cm^{3}}$

unit of length $=1 cm$

unit of mass $=1 g$

And in another system of units

The unit of mass is $100 g$ and unit of length is 10 $cm$, so substitute these values

Density $=\frac{4(\frac{100 g}{100})}{(\frac{10}{10} cm)^{3}}=\frac{(\frac{4}{100})}{(\frac{1}{10})^{3}} \frac{(100 g)}{(10 cm)^{3}}$

$=\frac{4}{100} \times(10)^{3} \cdot \frac{100 g}{(10 cm)^{3}}=40$ unit

Apart from fundamental and derived units, we have also used practical units e.g., horse power (h.p.) is a practical units of power. Practical units may or may not belong to a system but can be expressed in any system of units.