Direct Current and Circuit Laws

An electric current that flows in only one direction. It is used in devices that use batteries, like your phone.

The energy provided by a battery to each coulomb of charge passing through it. Measured in volts.

The potential difference across a battery when no current flows. Also measured in volts.

States that the sum of all currents entering a junction in a circuit is equal to the sum of all currents leaving that junction.

The internal resistance of a battery. It affects the amount of energy delivered to the circuit.

The sum of all voltage drops around a closed loop in a circuit is equal to zero.

The resistance of the load in a circuit, excluding the internal resistance of the battery.

Applies Ohm's Law to a circuit with a battery and internal resistance, relating EMF, terminal potential difference, current, and resistance.

The rate at which energy is consumed or generated in an electrical circuit. It is measured in watts (W).

The product of voltage (V) and current (I) flowing through a circuit element. Formula: P = I × V

The effect of electric current causing a conductor to heat up due to resistance. Example: A light bulb heats up when current flows through it.

The value of a voltage or current at a specific moment in time.

The number of complete cycles of an alternating current (AC) waveform per second. Measured in Hertz (Hz).

The time it takes for one complete cycle of an AC waveform. It is denoted by the letter T.

A graphical representation of an alternating variable (voltage or current) plotted against time.

The effective value of an alternating current, calculated as the root-mean-square (RMS) value. It represents the equivalent DC value that produces the same amount of power.

The effective value of an AC current is the RMS value or root mean square value, which is calculated by taking the square root of the average of the squares of the instantaneous values of the current over one cycle.

The effective value (RMS) of an AC current is equal to 0.707 times the peak value of the current.

Ohm's Law for AC circuits is similar to the DC version, but instead of resistance, it uses impedance (Z), which represents the total opposition to current flow in an AC circuit.

Impedance (Z) in an AC circuit is the combination of resistance (R) and reactance (X), which is the opposition to current flow due to capacitors or inductors in the circuit.

A capacitor is essentially a device that stores electrical energy in an electric field. It acts like an open circuit to direct current (DC) but allows alternating current (AC) to pass through.

The capacitive time constant (τ) of an RC circuit is the time taken for the capacitor to charge to approximately 63.2% of its maximum charge. It's calculated by multiplying the capacitance (C) and the resistance (R) in the circuit.

The impedance (Z) of a series R-C circuit is calculated using the Pythagorean theorem, where Z is the square root of the sum of the squares of resistance (R) and capacitive reactance (XC).

An inductor is a coil of wire that stores energy in a magnetic field when current flows through it. It opposes changes in current, acting like a short circuit to DC but resisting AC.

In a series R-L circuit, impedance (Z) is the total opposition to the flow of alternating current. It combines the resistance (R) and the inductive reactance (XL) using the Pythagorean theorem.

The time constant of an RL circuit represents the time it takes for the current to reach approximately 63.2% of its final steady-state value.

An AC circuit is an electrical circuit that utilizes alternating current (AC). It is commonly used in power systems and appliances.

Impedance (Z) in an RLC circuit is the total opposition to current flow, considering resistance (R), inductive reactance (XL), and capacitive reactance (XC). It is calculated using the Pythagorean theorem, combining all three components.

AC is widely used in homes and offices for powering appliances because it can be easily transformed to high voltages for efficient transmission and back to low voltages for safe usage.