Question

If a gas kept at 1 bar pressure, has it volume decreased and made $\frac{1}{4}$ of the initial volume, then its pressure becomes, if the temperature remains constant :

• A. 1 times
• B. 2 times
• C. 4 times
• D. $\frac{1}{4}$ times

Answer 1

The correct option is C 4 times

$P_1{V}_1=P_2{V}_2$ (at constant temperature, by Boyle's law)
From the given question:
$P_1=1$ bar
$V_1=V$
$P_2=?$
$V_2=\frac{1}{4}V$
Substituting the values in the above equation, we get
$1\times V=P_2\frac{1}{4}V$
$\frac{4\times V}{V}=P_2$
4 bar $=P_2$
As $P_1$ was 1 bar. Hence, the pressure becomes 4 times.