Concepts to remember for JEE and CBSE board exams on the of Electrical Energy and Power:

1. Power:

• Power is the rate at which electrical energy is consumed or generated.
• The SI unit of power is Watts (W).
• $$P = VI$$ [Formula]
• Factors affecting power are: voltage, current, and resistance.
• Power rating refers to the maximum amount of power an electrical device can safely handle.

2. Energy:

• Electric energy is the capacity of an electric current to do work.
• The SI unit of energy is Joules (J) or kilowatt-hours (kWh).
• $$E = Pt$$ [Formula]
• Factors affecting energy are: power, time, and voltage.
• Energy consumption refers to the amount of electrical energy used by a device or system.

3. Current and Voltage:

• Electric current (I) refers to the flow of electric charge (electrons) through a conductor. The standard unit for measuring current is the ampere (A).
• Voltage (V) refers to the electrical potential difference between two points in a circuit or the energy per unit charge that results in motion through the said circuit; its unit of measurement is the volt (V).
• Ohm’s Law: V = I × R where R = resistance

4. Circuits:

• Electrical circuits consist of conductive pathways allowing currents to flow, typically containing sources of electric potential, loads like light bulbs, resistors, switches, transformers, etc.
• There are two primary types of circuit configurations: • Series circuit: Elements are connected end-to-end where charges follow one specific path; the total current for an entire series is equivalent to that passing through any component of the same series
  • Parallel circuit: Elements are connected side-by-side, providing several alternate routes for current flow.
• Series, Parallel combinations [Variations/Special cases]

5. AC Circuits:
-Alternating current involves periodically reversing current direction and continuously shifting through a sine wave pattern.

• Alternating current (AC) circuits feature continually changing directions in power flow and involve parameters like frequency, phase angle, reactance, and impedance in their analyses.

• Frequency determines how rapidly AC waveforms complete cycle reversals measured in Hertz (Hz).
• Voltage and current can be “out of sync” with phase angles as an additional circuit trait to comprehend [Phase shifts]