Electric Current and Its Effects

Electric Current and Its Effects – Class 7 Science

Electricity is a vital part of our daily lives. We use it for lighting, running fans, refrigerators, televisions, and many more appliances. But do you know what actually flows through the wires? It is electric current! Let’s understand what electric current is and the effects it can produce.

What is Electric Current?

Electric current is the flow of electric charge through a conductor. It flows from the positive terminal of the battery to the negative terminal when the circuit is complete.

A device like a bulb, fan, or heater works only when the circuit is complete, i.e., when the current flows through it.

Components of an Electric Circuit

• Battery or Cell: Provides the electric current.
• Wires: Conductors that allow the current to flow.
• Bulb or Device: Uses the electric energy.
• Switch: Controls the flow of electricity.

Effects of Electric Current

Electric current produces various effects. The main effects are:

1. Heating Effect: When current flows through a wire, it heats up. This is used in electric heaters, toasters, and irons.
2. Magnetic Effect: Current flowing through a wire creates a magnetic field. This is used in devices like electric bells, motors, and fans.
3. Chemical Effect: When current passes through liquids, it can cause chemical changes. This is used in electroplating and purification of metals.

Electric Fuse

An electric fuse is a safety device used in circuits. It protects appliances by breaking the circuit when too much current flows through it.

Example: When the current becomes too high, the fuse wire melts and stops the flow of electricity to prevent damage.

Electromagnet

When an electric current passes through a coil of wire wrapped around an iron nail, it behaves like a magnet. This temporary magnet is called an electromagnet. It is used in cranes to lift heavy iron objects and in electric bells.

Electric Bell – Working Principle

The electric bell works on the magnetic effect of current. When the current flows through the coil, it becomes an electromagnet and attracts the hammer which hits the gong. This breaks the circuit, and the process repeats rapidly, producing a ringing sound.

Conclusion

Electric current is a powerful form of energy that not only lights our homes but also runs various appliances and gadgets. Understanding its effects helps us use electricity wisely and safely.

Always handle electrical appliances carefully and never touch a switch or socket with wet hands!