Question

Convection currents are possible in solids
(A) True
(B) False

Answer 1

Hint : Convection current is the bulk movement of the molecules of the material to transfer heat from one region to another. This happens in materials whose molecules are free to move around.

Complete step by step answer
Generally heat can be transferred in three different methods, they are: conduction, convection and radiation.
Convection: This is a mode of heat transfer where the molecules of the material itself are macroscopically moving to redistribute heat. It happens as a result of density and buoyancy. When a liquid is poured into a container and is heated from below, the molecules of the liquid at the bottom get heated first. This heating increases their volume and hence reduces their density. This allows the molecules to become lighter than the molecules at the top, hence begins to rise to the top as though to float and the molecules at the top hence, sinks to the bottom. Then the top molecules now at the bottom get heated, and become hotter than the molecules at the top, then rise to the top due to reduced density while the one at the top sinks to the bottom. The process repeats until some molecules start to vaporize. The movement of the molecules during this process are called convection current. And they are observed in liquids and gas.
The intermolecular forces among molecules are too strong to allow heated molecules to rise to the top even when they expand.
Hence, the correct option is B.

Note
For clarity, increase in temperature for most substances allows the volume to be increased, and since density is mass divided by the volume, the density reduces when the volume increases.
Also, convection does not happen to all liquids or gas at all temperatures. If the liquid contracts when there is a rise in temperature, such liquids do not undergo convection.