Q. How does a pressure cooker help in easy and fast cooking?
Ans. A pressure cooker is made air-tight with the help of a sealing ring fitted in its lid. It prevents the steam from escaping the cooker. Thus, when the liquid boils inside the cooker, more and more steam gets entrapped in it raising the internal pressure. Now, as per the Gas law, pV = nRT (p = pressure of gas, V= volume of the gas, n = number of moles of gas, R = gas constant ant T = temperature of gas), i.e., increase in pressure directly correlates to an increase in temperature. Therefore, the temperature inside the cooker also increases hence helping to cook the food faster.