Question

What causes convection currents in the air?

• A. The revolution of the earth around the sun.
• B. The rotation of earth around itself.
• C. The heat on the surface of the earth.
• D. The uneven shape of the earth.

Answer 1

The correct option is C The heat on the surface of the earth.

When liquids or gases get heated, their volume increases, making them less dense. Thus, the less desne region rises up, and makes way for the cooler and denser part of the liquid to take its place. This process is called convection.
Thus, convection currents in air are caused by the heat on the earth's surface.