Question

The density of a material in $CGS$ system of units is $4g/c{m}^3$. 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. $0.04$
• B. $0.4$
• C. $40$
• D. $400$

Answer 1

The correct option is C $40$

Let unit of mass be $M=100g$ and length be $L=10cm$

So $\frac{M}{100}=g$ and $\frac{L}{10}=cm$

Substituting these we get:

$4g/c{m}^3=4\times \frac{M}{100}\times \frac{{10}^3}{L^3}=4\times 40\frac{M}{100}\times \frac{1000}{L^3}=40M/L^3$

Hence the correct option is (C).