What are the units of the electric field E?

• A. N
• B. C
• C. N/C
• D. J/C

Answer: (C)

Electric field strength is defined as the force experienced by a test charge per unit of charge, E = F/q. Since force is measured in newtons and charge in coulombs, the SI units are newtons per coulomb (N/C). This is also equivalent to volts per meter (V/m) because 1 N/C = 1 V/m. For intuition, a field of 1 N/C would push a 1 C test charge with a 1 N force. Energetic units like J/C measure energy per charge, not force per charge, so they don’t describe the field’s units.