Defence GK Questions 2026

In summer, as the subtropical westerly jet withdraws to the north of the plateau of Tibet, an easterly jet stream forms in the upper air over peninsular India and blows from east to west.

Strong heating at the equator makes the air expand and rise, so surface pressure is low and horizontal winds are weak; sailing ships were often becalmed there.

It is a cold, dry and often violent wind that blows from the north down the Rhone valley of southern France to the Gulf of Lion, chilling the coast and damaging crops, which is why orchards there are protected by lines of trees and walls.

It states the deflection produced by the rotation of the earth, the Coriolis effect, which turns every freely moving body to the right of its path in the northern hemisphere and to the left in the southern.

It is a strong, hot and dry wind that blows during the day over the plains of north India and Pakistan in the peak of summer, raising temperatures sharply and causing heat stroke, and it dies down after sunset.

The wind is the Chinook. It descends the leeward slope, is compressed and warmed as it sinks, and can raise the temperature sharply in a few hours; it melts or evaporates the snow cover, which is why herders call it the snow eater and why it is valued for exposing…

It is comparatively inert, so it dilutes oxygen and slows combustion, and it enters living things mainly through the nitrogen cycle in which bacteria fix it in a usable form.

Although the air there is thin, it is dense enough to heat a body moving at cosmic speed by friction, so most meteors glow and are destroyed in this layer and are seen from the ground as shooting stars.

This is the average rate at which air temperature falls as one rises through the troposphere, and it explains why hill stations are cooler than the plains and why high peaks carry snow even in the tropics.

Ozone is concentrated in the lower and middle stratosphere, and because it absorbs ultraviolet radiation the temperature of this layer rises with height instead of falling.

If each length of a solid grows by a certain small fraction when it is heated, an area, which is the product of two lengths, grows by about twice that fraction, and a volume, the product of three lengths, by about three times.

An adiabatic change is one in which no heat is exchanged with the surroundings.

A cooker is sealed, so the steam it produces cannot escape and the pressure inside rises. Since the boiling point of a liquid rises with the pressure on it, water in a cooker boils well above a hundred degrees Celsius, and food cooking at that higher temperature is ready sooner.

The efficiency of an ideal Carnot engine is one minus the ratio of the sink temperature to the source temperature, both in kelvin.

The space between the sun and the earth is very nearly empty, and radiation is the only mode of heat transfer that needs no material medium: energy travels as electromagnetic waves at the speed of light and is absorbed when it strikes matter.

It states that if body A is in thermal equilibrium with body C, and body B is also in thermal equilibrium with body C, then A and B are in thermal equilibrium with each other.

The first law says that the heat supplied to a system is equal to the increase in its internal energy plus the external work it does.

Both of these modes need matter: conduction passes energy from particle to particle and convection carries it by the movement of a fluid.

This is the heat that one gram of water at a hundred degrees Celsius must absorb to become steam at the same temperature, with no rise in temperature at all; the same quantity is released when steam condenses back to water.

Water behaves abnormally between zero and four degrees: it contracts as it is heated in that range and expands again above four degrees, so the same mass occupies its least volume, and therefore has its greatest density, at four degrees Celsius.