A balloon carries a total load of $185 \mathrm{~kg}$ at normal pressure and temperature of $27^{\circ} \mathrm{C}$. What load will the balloon carry on rising to a height at which the barometric pressure is $45 \mathrm{~cm}$ of $\mathrm{Hg}$ and the temperature is $-7^{\circ} \mathrm{C}$. Assuming the volume constant ?
Correct Option: , 4
$\mathrm{P}_{\mathrm{m}}=\rho \mathrm{RT}$
$\therefore \frac{P_{1}}{P_{2}}=\frac{\rho_{1} T_{1}}{\rho_{2} T_{2}}$
$\frac{\rho_{1}}{\rho_{2}} \Rightarrow \frac{P_{1} T_{2}}{P_{2} T_{1}}=\left(\frac{76}{45}\right) \times \frac{266}{300}$
$\frac{\rho_{1}}{\rho_{2}} \Rightarrow \frac{M_{1}}{M_{2}}=\frac{76 \times 266}{45 \times 300}$
$\therefore \mathrm{M}_{2} \Rightarrow \frac{45 \times 300 \times 185}{76 \times 266}=123.54 \mathrm{~kg}$