Sign up ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

Recently, I have stumbled upon a YouTube video by Veritasium describing the conductivity of fire. My question is: how exactly does fire conduct electricity? I am a high school student; therefore appropriate language is expected.

share|cite|improve this question
I believe you meant flame, which can contain ionized gas. That should conduct if a non-negligible number of charge carriers are present. – liberias Nov 26 '12 at 2:19
Related (nearly a duplicate): – dmckee Jan 16 '13 at 17:39
FWIW, there are devices known as flame detectors; among their applications are safety devices in domestic furnaces. Some flame detector designs are based on the fact that a flame contains ionized gas (plasma) and is therefore conductive. – Anthony X Aug 20 '13 at 2:52

3 Answers 3

This video illustrates how a candle flame conducts a high voltage (10,000 volts). Although the ion density is small in a candle flame, they are sufficiently present to conduct electricity.

share|cite|improve this answer

Fire is a plasma and plasmas conduct electricity. This is because in a plasma an important portion of the atoms are ions. This means that there are free charges on the plasma that move if a voltage is applied to the plasma, this creates a current.

share|cite|improve this answer
Most sources don't consider the ion density in fire to be sufficiently high to be classified as plasma. However, at high voltages, electrical conduction can occur in spite of the low ion density. – Michael Luciuk Nov 26 '12 at 17:45

actually, the fire does not conduct electricity, it simple ionises the air around it and the free electrons create a conducting path across the gap

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.