In Ohm's law, what does the symbol E represent?

In Ohm's law, what does the symbol E represent?

• A. Current
• B. Voltage
• C. Resistance
• D. Power

Answer: (B)

E represents the voltage, the electrical potential difference that drives current through a circuit. In Ohm’s law, the relationship is current = voltage divided by resistance, so the driving potential difference across a component sets how much current flows for a given resistance. Some texts use E to denote electromotive force (the total energy per unit charge provided by a source), but for simple circuit problems it’s treated as the voltage across the element. The other quantities in the choices (current, resistance, and power) are represented by different symbols (I, R, and P), not E. So, in this context, E is the voltage.

E represents the voltage, the electrical potential difference that drives current through a circuit. In Ohm’s law, the relationship is current = voltage divided by resistance, so the driving potential difference across a component sets how much current flows for a given resistance. Some texts use E to denote electromotive force (the total energy per unit charge provided by a source), but for simple circuit problems it’s treated as the voltage across the element. The other quantities in the choices (current, resistance, and power) are represented by different symbols (I, R, and P), not E. So, in this context, E is the voltage.