Question

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

• A. 0.4
• B. 40
• C. 400
• D. 0.04

Answer 1

Answer: (B)

40

In CGS, $d=4\frac{g}{{cm}^3}$
If unit of mass is $100g$, 4 g mass in new units is $\frac{4}{100}$ units

and unit of distance is $10cm$, 1 cm in new units is $\frac{1}{10}$ units

So, density $=\frac{4\left(\frac{g}{100}\right)}{{\left(\frac{1}{10}cm\right)}^3}$$=\frac{\left(\frac{4}{100}\right)}{{\left(\frac{1}{10}\right)}^3}=40units$