What is a convection current?

A convection current is the way that heat is transferred throughout a fluid. By fluid, we mean a liquid or a gas, where the molecules are free to move. Imagine a cup of water being heated from the bottom. The heat being supplied to the water increases the energy of the molecules at the bottom of the cup first. The water at the bottom becomes hotter and less dense as the molecules gain energy and spread out. The hot water then rises and the colder water that was at the top sinks to the heat source, as it is more dense. The hot water which has risen cools and the water that sinks is heated, and the process repeats itself. This movement of molecules due to heat transfer is known as a convection current.

Answered by Luke C. Physics tutor

5738 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

A balloon's volume is 0.002m^3 at room temperature (20°C). What volume will the balloon occupy when it is cooled to -5°C? Give your answer to 3 significant figures.


A ball of mass 500g is dropped from rest 2m above the ground. When it reaches the ground it is travelling at 5m/s. How much energy has been dissipated?


A force of 13.8 N was used to lift a mass 30 cm vertically through a liquid. Calculate the work done in lifting the mass, stating the correct units.


What is an (electrostatically) induced charge?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences