Define current and mention its unit?

Simple Answer:

Current is the flow of electric charge in a circuit. It is the movement of tiny particles called electrons through a conductor like a wire. Current flows when there is a voltage to push the electrons. Without current, electrical devices cannot work.

The unit of current is ampere (A), named after André-Marie Ampère, a scientist who studied electricity. One ampere is defined as the flow of one coulomb of charge per second. A higher current means more electricity is flowing in the circuit.

Detailed Explanation:

Current is one of the most important concepts in electricity and is necessary for all electrical systems to function.

What is Current?

  • Current is the flow of electric charge in a circuit.
  • It is caused by the movement of electrons in a conductor, such as a metal wire.
  • It is measured in amperes (A) and represented by the symbol I.
  • Current flows from the positive terminal to the negative terminal of a battery or power source (conventional current direction).

Types of Current:

  1. Direct Current (DC):
    • Flows in one direction only.
    • Found in batteries, solar panels, and electronic circuits.
  2. Alternating Current (AC):
    • Changes direction many times per second.
    • Used in homes, industries, and power grids.

Unit of Current – Ampere (A):

  • The unit of current is ampere (A).
  • One ampere is defined as one coulomb of charge passing through a conductor per second.
  • Example: If 6 coulombs of charge pass through a wire in 2 seconds, the current is:

I=Qt=6C2s=3AI = \frac{Q}{t} = \frac{6C}{2s} = 3AI=tQ​=2s6C​=3A

Examples of Current in Daily Life:

  1. Household Electricity – Appliances like TVs and refrigerators use AC current from the power supply.
  2. Batteries – A torchlight or remote control works on DC current from batteries.
  3. Phone Charging – A charger supplies a specific amount of current to charge the battery.
Conclusion:

Current is the flow of electric charge, measured in amperes (A). It is essential for all electrical devices and circuits. Understanding current helps in designing and troubleshooting electrical systems efficiently.