Electricity and Magnetism

Electric power, heating effect of current

Electric power is the rate at which electrical energy is consumed or produced in a circuit.
The formula for electric power is P = VI, where P is power, V is voltage, and I is current.
Using Ohm’s law, power can also be expressed as P = I²R or P = V²/R, where R is resistance.
Its SI unit is the watt (W), where 1 watt = 1 joule/second.
In household applications, power is often measured in kilowatts (kW).
The energy consumed i

In a series circuit, components are connected end-to-end so that the current flows through each component sequentially.
The same current flows through all components in a series circuit.
The total resistance in a series circuit is the sum of individual resistances: R_total = R1 + R2 + R3 + ...

Electric current is the rate of flow of electric charge through a conductor.
The formula is I = Q/t, where I is current, Q is charge, and t is time.
It is a scalar quantity and is measured in amperes (A).
In metallic conductors, current is due to the motion of free electrons.
Electric current can be direct (DC) or alternating (AC).
The direction of conventional current is opposite to the motion of electrons

Electric potential is the amount of work done to bring a unit positive charge from infinity to a point in an electric field.
It is a scalar quantity and is measured in volts (V).
The formula for electric potential due to a point charge is \( V = k \frac{q}{r} \), where \( q \) is the charge and \( r \) is the distance.
The reference potential is usually taken as zero at infinity.
Positive charges create regions of high potential, and ne

Electric charge is a fundamental property of matter that causes it to experience a force in an electric field.
There are two types of charges: positive and negative.
Like charges repel each other, and unlike charges attract each other.
Charge is measured in coulombs (C).
Quantization of charge states that charge exists in discrete packets, as multiples of the elementary charge e (1.6 × 10^-19