Physics - Electricity (Static Electricity, Current, Circuits, Heating/Chemical effects)

Static Electricity: This involves the study of electric charges at rest. Charging an object can occur via friction, conduction, or induction. The fundamental unit of charge is the Coulomb ($C$).

Electronic Theory: An atom is electrically neutral. An object becomes positively charged by losing electrons and negatively charged by gaining electrons. The charge of a single electron is approximately $-1.6 \times 10^{-19}\ C$.

Electric Current ($I$): It is defined as the rate of flow of electric charge through a conductor. Measured in Amperes ($A$).

Potential Difference ($V$): The amount of work done in moving a unit positive charge from one point to another. Measured in Volts ($V$).

Resistance ($R$): The obstruction offered by a conductor to the flow of current. It depends on the material, length, area of cross-section, and temperature. Measured in Ohms ($\Omega$).

Series Circuit: Components are connected end-to-end. The current ($I$) remains the same through all components, while the total potential difference ($V$) is the sum of individual voltages.

Parallel Circuit: Components are connected across the same two points. The potential difference ($V$) remains the same, while the total current ($I$) is the sum of currents through individual branches.

Heating Effect of Current: When current passes through a high-resistance wire (like Nichrome), electrical energy is converted into heat energy. This is governed by Joule's Law: $H = I^2Rt$.

Chemical Effect of Current: The passage of electric current through a conducting solution (electrolyte) causes chemical reactions. Key processes include electrolysis and electroplating. Cations ($+$) move toward the Cathode ($-$) and Anions ($-$) move toward the Anode ($+$).

Safety Devices: An electric fuse is a safety device with a low melting point that breaks the circuit during overloading or short-circuiting.