“When an electric current passes through a bulb or any conductor, the conductor presents a level of opposition to the current, referred to as electrical resistance and symbolized as ‘R.’ Every substance exhibits electrical resistance, which is why conductors generate heat when current flows through them. In the forthcoming sections, we will delve deeper into the topic of electrical resistance.”

Key points about electrical resistance:

  1. Origin: Electrical resistance arises due to collisions between electrons and atoms or other electrons within the material. These collisions generate heat and reduce the flow of electrons, impeding the current.
  2. Material Dependency: Different materials have different electrical resistances. Some materials, like metals (e.g., copper, aluminum), have low resistance and are good conductors of electricity. Others, like rubber or plastic, have high resistance and are insulators.
  3. Temperature Dependency: Resistance is often temperature-dependent. In many materials, resistance increases as temperature rises because higher temperatures lead to more electron-atom collisions. However, this isn’t the case for all materials; for instance, in superconductors, resistance drops to zero at very low temperatures.
  4. Length and Cross-Sectional Area: The resistance of a conductor also depends on its length and cross-sectional area. Longer conductors generally have higher resistance, while wider conductors have lower resistance.
  5. Ohm’s Law: Ohm’s Law, formulated by Georg Simon Ohm, describes the relationship between voltage (V), current (I), and resistance (R): V = I * R. This law is fundamental in understanding and calculating electrical circuits.
  6. Resistors: Components known as resistors are designed to have a specific resistance and are used in electronic circuits to control the flow of current. They are often marked with color-coded bands to indicate their resistance value.
  7. Series and Parallel Resistance: In a circuit, resistors can be connected in series or parallel. In series, their resistances add up, while in parallel, the total resistance is reduced.