Potential Difference and Electrical Power in Circuits

Potential Difference

Energy transferred per unit charge in a circuit.

Voltage

Another term for potential difference, measured in volts (V).

Volt (V)

Unit of potential difference; 1 V = 1 J/C.

Energy Transfer

Amount of energy moved per charge in a circuit.

Voltmeter

Device to measure potential difference across components.

Series Circuit

Circuit where potential difference is shared among components.

Parallel Circuit

Circuit where potential difference is the same across components.

Work Done (W)

Energy transferred when a force moves an object.

Charge (Q)

Electric property measured in coulombs (C).

Power (P)

Rate of doing work, measured in watts (W).

Current (I)

Rate of flow of charge, measured in amperes (A).

Power Equation

P = IV; relates power, current, and potential difference.

Resistance (R)

Opposition to current flow, measured in ohms (Ω).

Ohm's Law

V = IR; defines relationship between voltage, current, and resistance.

Energy per Coulomb

Potential difference viewed as energy transferred per charge.

Power Dissipation

Energy converted to another form per unit time.

P = I²R

Power equation using current and resistance.

P = V²/R

Power equation using voltage and resistance.

Brighter Lamp

Higher potential difference results in greater brightness.

Energy Transfer Comparison

240 V lamp transfers 20 times more energy than 12 V.

Twinkle Mnemonic

Helps remember power equations: P = I²R.

Normal Brightness

Condition when lamps operate at designed current levels.

Current Calculation

I = P/V; used to find current in circuits.

Coulomb (C)

Unit of electric charge.

Energy Transfer Formula

V = W/Q; defines potential difference in terms of work.