What are the standard SI units for electric field and potential?

What are the standard SI units for electric field and potential?

• A. E in N/C or V/m; V in volts
• B. E in J/C; V in volts
• C. E in V/m; V in N/C
• D. E in C/N; V in volt

Answer: (B)

Electric field units come from E = F/q, so its SI unit is newtons per coulomb. Since N/C is the same as V/m (because E = -dV/dx), you can express the field either way. Electric potential is measured in volts, and one volt is defined as one joule per coulomb, so its unit is V (which equals J/C). So the standard pairing is E in N/C or V/m, and potential in volts (V). The option that assigns the field unit as J/C would mix units that belong to potential with the field, since J/C is the unit of potential, not the field.

Electric field units come from E = F/q, so its SI unit is newtons per coulomb. Since N/C is the same as V/m (because E = -dV/dx), you can express the field either way. Electric potential is measured in volts, and one volt is defined as one joule per coulomb, so its unit is V (which equals J/C).

So the standard pairing is E in N/C or V/m, and potential in volts (V). The option that assigns the field unit as J/C would mix units that belong to potential with the field, since J/C is the unit of potential, not the field.