Question

The tyre of motor car contains air at ${15}^{0}C$. If the temperature increases to ${35}^{0}C$ the approximate percentage increase in pressure is (ignore expansion of tyre) ($P\propto T$):

• A. 7
• B. 9
• C. 11
• D. 13

Answer 1

The correct option is A 7

As $P\alpha T$ from Charles law,

Hence,

$\frac{P_2}{P_1}=\frac{T_2}{T_1}⟹\frac{(P_2-P_1)}{\left(P_1\right)}\times 100=\frac{T_2-T_1}{T_1}\times 100$

$⟹\frac{\Delta P}{P}\times 100=\frac{20}{298}\times 100=7$