Definitions of Voltage, Current, & Resistance

Flashcards about Voltage, Current, Resistance, Ohm's Law, Series and Parallel Resistors, Ammeters and Voltmeters, and Power.

Voltage

Provided by a battery and measured in volts [V].

Current

Relates to the amount of charge flowing through part of a circuit and is measured in amps [A].

Resistance

Provided by a resistor, a lamp, or any electronic device and is measured in Ohms [Ω].

Ohm’s Law

Voltage is equal to current multiplied by resistance: V = I ∙ R

Resistors in Series

Resistors connected in a single path.

Equivalent Resistance of Series Resistors

The sum of all of the individual resistors.

Series Resistors Current

Carry the same current, which is equal to the total current through the path.

Voltage Across Series Resistors

Is different for each resistor, but all add to the voltage of the battery.

Resistors in Parallel

Resistors are connected in parallel if the path for current divides, then comes immediately back together.

Equivalent Resistance of Parallel Resistors

Is less than any individual resistor.

Voltage Across Parallel Resistors

Is the same for each resistor, and equal to the total voltage.

Parallel Resistors Current

Each carry different currents, which add to the total current in the circuit.

Ammeter

Measures current through a resistor and is connected in series with a resistor.

Voltmeter

Measures voltage across a resistor and is connected in parallel with a resistor.

Power Dissipated by a Resistor

The power dissipated by a resistor is equal to the resistor’s voltage squared divided by its resistance: 𝑃 = 𝑉2 𝑅.

Power

Measured in units of watts [W].

Brightness of a Light Bulb

Depends on the power dissipated by the bulb.