Resistance is the measure of how much a material or device impedes the flow of electric current. It is measured in units called ohms (Ω).
Ohm's Law is a fundamental relationship in physics that describes the relationship between voltage, current, and resistance in an electrical circuit. It states that the current through a conductor is directly proportional to the voltage and inversely proportional to the resistance.
Resistance can be calculated by dividing the voltage (V) by the current (I). The formula for resistance is R=V/I. This can also be rearranged to find the voltage or current if the other two values are known.
The factors that affect resistance include the type of material, the length and cross-sectional area of the conductor, and the temperature. Materials with higher resistivity, longer lengths, and smaller cross-sectional areas will have higher resistance. Temperature also affects resistance, with most materials having higher resistance at higher temperatures.
Resistance plays a crucial role in the function of electrical circuits. It helps to regulate and control the flow of current, preventing it from becoming too high and causing damage to the circuit components. Resistance can also be used to transform electrical energy into other forms, such as heat, light, or sound, in devices like heaters, light bulbs, and speakers.