Question

When the sun is overhead on the Tropic of Capricorn (22nd December) the pressure belts shift ____________.
A. 5°N
B. 5°S
C. 15°N
D. 15°S

Answer 1

Hint: The pressure conditions extensively vary in January and July because of the inclination of the earth on its axis and the differences in the temperatures of the oceans, and continents.

Complete Answer: The circle of latitude that contains the subsolar point at the December or southern solstice is known as the Tropic of Capricorn. There are five major circles of latitude marked on maps of the earth, one of them is the Tropic of Capricorn.
The global horizontal distribution of pressure is the distribution of atmospheric pressure across the latitudes. The pressure gradients are the air movements that have their origins in pressure differentials in the atmosphere.
Air pressure is affected by the systematic differences in the land temperature of the earth. Hence, Pressure belts are the major patterns of pressure that persist over a period of time. Temperature plays an important role as a change in temperature can move the belts and wind patterns.
The belt would have been stationary and permanent in the absence of the earth's revolution around the sun. But the relative position of the earth changes because of the revolution of the earth. Except for the polar high-pressure belts, the position of all the pressure belts changes.
When the sun is overhead on the tropic of Cancer, on June 21, then the pressure belt shifts 5 degrees northwards and on December 22, when the sun shines overhead on the Tropic of Capricorn, the pressure belt shifts 5 degrees southwards.

Thus the correct option is B.

Note: On March 21st and September 23rd, the pressure belts remain unchanged in both the hemispheres when the sun glows vertically over the equator.