In the equation E = I × R, what does E represent?

In the equation E = I × R, what does E represent?

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

Answer: (B)

This item tests Ohm’s law in the form E = I × R. Here, E represents voltage (the electrical potential difference that drives current through the circuit). The current I is the rate of charge flow, and R is the opposition to that flow (resistance). Multiplying current by resistance gives the voltage drop across the component, so E equals I times R. For example, if 2 A flow through a 3 Ω resistor, the voltage across it is 6 V. This isn’t current or resistance, and while power can be found from P = V × I, the given relation specifically defines E as voltage, not power. In some texts, E is also called electromotive force, reinforcing that it’s the driving voltage in the circuit.

This item tests Ohm’s law in the form E = I × R. Here, E represents voltage (the electrical potential difference that drives current through the circuit). The current I is the rate of charge flow, and R is the opposition to that flow (resistance). Multiplying current by resistance gives the voltage drop across the component, so E equals I times R. For example, if 2 A flow through a 3 Ω resistor, the voltage across it is 6 V. This isn’t current or resistance, and while power can be found from P = V × I, the given relation specifically defines E as voltage, not power. In some texts, E is also called electromotive force, reinforcing that it’s the driving voltage in the circuit.