Q. Doldrums are ________ 

Explanation by: Jitendra Singh

Doldrums are Equatorial zone with low pressure. As this region lies along the equator, it receives highest amount of insolation. Due to intense heating, air gets warmed up and rises over the equatorial region (convection). Whenever there is vertically upward movement of air, the region at the surface will be at low pressure. Thus the belt along the equator is called equatorial low pressure belt.