# Is there a difference between joules of energy per coulomb and volts?

There is a question in my textbook:

A current of $7\ \mathrm{A}$ goes through the heating element in a hair-drier. The voltage of the heating element is $240\ \mathrm{V}$.

b) How many joules of energy does each coulomb supply to the element as it goes through?

I understand this is a simple problem.

So it's 240 volts. Can this just be changed to 240 joules per coulomb? Is voltage and energy per unit charge related?

• I fixed up some confusion between units and the quantities they measure in the edit I made. – David Z May 13 '17 at 3:46
• Joules express energy, Coulombs charge, and Amps current (charge/second). Can you take it from here? – hdhondt May 13 '17 at 4:04
• Two points differ in potential by one volt if the work done in taking one coulomb between those two points is one joule. – Farcher May 13 '17 at 5:29
• You're absolutely correct – Ofek Gillon May 13 '17 at 8:16

$1$ J is the work done in taking 1 C between a potential difference of 1 V. Then, since the electric work is $qU$, $1\, J = 1\, C\cdot V$, or $1\,V = 1\,J/C$: you were right.