Question

If rice is cooked in a pressure cooker on the Siachen glacier, at sea beach, and on Deccan plain, which of the following is correct about the time taken for cooking rice?
(A)Gets cooked faster on the Siachen glacier
(B)Gets cooked faster at sea beach
(C)Gets cooked faster on Deccan plain
(D)Gets cooked at the same time at all the three places.

Answer 1

Siachen glacier, Deccan plan and sea-beach all are at different altitudes. The temperature in each place also varies. In higher altitudes the pressure is low and the temperature is low, the boiling point of water increases.

Complete step by step answer:
At low temperatures and higher altitudes, rice gets cooked easily in an open vessel.
We know that as the altitude increases, the pressure decreases. That is, pressure and altitude are inversely proportional to each other.
$pressure\propto \dfrac{1}{altitude}$
Siachen glacier is present in higher altitudes than that of the deccan plane and sea-beach. The Deccan plan is at a higher altitude than that of the sea-beach. Sea-beach is ground level, so its altitude is 0. The Deccan plane has an altitude between the Siachen glacier and the sea-beach.
Pressure order will be [Siachen~glacierRice is cooked easily at lower temperature and higher altitudes due to atmospheric pressure. At sea-beach level the temperature is high and the pressure is high when compared to higher altitudes. So, the water will boil easily and rice will get cooked easily in a pressure cooker.
Thus, rice when cooked in a pressure cooker gets cooked faster at sea beach.
Additional Information: Atmospheric pressure decreases with altitude due to two reasons. Both the reasons are related to gravity. Near the earth, the gravitational attraction between the earth and air molecules is greater than those in higher altitude. So, they have more weight and they are close together and the pressure between them increases. Another reason is that in the higher altitudes, the gravitational attraction is less and the molecules have less weight and are not compressed.
So the correct answer is option B.

Note:
We should always keep in mind that high altitude means low pressure. At higher temperature and high pressure or low altitude, it is easy for the water to boil.