Question 6A21

Resistance is a fundamental electrical property that opposes the flow of current. A) **The quantity which determines power loss or dissipation:** This is correct. According to Joule's Law (P = I²R or P = V²/R), resistance (R) directly determines the power (P) dissipated as heat for a given current (I) or voltage (V). This is crucial for understanding efficiency in circuits, like RF amplifiers and transmission lines, where unwanted power loss manifests as heat. B) **The factor of proportionality between voltage and current:** This is also correct. Ohm's Law states V = IR, where V is voltage, I is current, and R is resistance. Rearranging this to R = V/I shows that resistance is the constant that relates the voltage across a component to the current flowing through it. C) **Measured in ohms:** This is correct. The standard unit of measurement for resistance is the ohm, symbolized by Ω, named after Georg Ohm, who first described the relationship between voltage, current, and resistance. Since all three statements accurately describe properties or characteristics of resistance, "All of the above" is the correct and most complete answer.