Blog Tag Electromagnet

Uses of Electromagnets

Electromagnets are used at different places in our daily life. In electrical appliances such as electric bell, electric fan, electric motors, etc. In lifting heavy loads of iron scrap. To remove tiny particles of iron from wound. In loading furnaces with iron. In the separation of iron ores (magnetic substances) from impurities (non-magnet . . .

Miniature circuit breaker (MCB)

A miniature circuit breaker is an automatically operated electric switch that protects an electric circuit during an overload or short circuit. They can be reset (manually or automatically) to restore normal operation, whereas in circuits with fuses, the fuse needs to be replaced after a single use. . . .

Terms related with Electricity

Current: The flow of electricity is called current. Voltage: The voltage applied across a device causes current to flow through it. The greater the voltage across a device, the greater is the current through it. Volts: Voltage is measured in volts. Battery: A group of connected cells is call battery. Electric circuit: A path along which an e . . .

Resistance

The electrical resistance of a piece of material is a measure of the hindrance it creates to the flow of electric current. The lower the resistance the greater is the current. . . .

Heat produces depends on resistance

The higher the resistance the greater the current, the greater is the heat produced. For example: Connect a bulb to a battery. After some time, touch the wires and the bulb. You find that the bulb is much warmer than the wires because the resistance of the filament of the bulb is higher than that of the wires. . . .

Heat produced depends on current

The greater the current, the greater is the heat produced. For example: Connect the terminals of a cell with a wire for a few seconds. The wire will get very hot. The wire has a low resistance, which allows a large current to flow in the circuit. This produces a large amount of heat, which makes the wire hot. Connect a bulb to the cell. The r . . .

Disadvantages of heating effects of current

When an electric current flow through a conductor, a part of the electrical energy is converted into heat energy. This is a waste of energy. The heat produced can damage the insulation on wire, damage electrical components or cause fires. Devices like TVs, music system and computers have vents to allow air to cool them. Computers even have fans f . . .

Risk of overload: things to avoid

Putting too much pressure on a water hose can make it burst. The principle is similar for electric wires: if too great a current flow is required by several items of equipment connected to the same line, this produces overload. Avoid therefore as far as possible: plugging several power-hungry items of equipment into the same socket using a m . . .

Relation of Short circuit with overload

A short circuit is a direct low resistance connection between two pointes across which there is a voltage. Due to overload (too much current flow) occurs short circuit. A short circuit is simply a low resistance connection between the two conductors supplying electrical power to any circuit. This results in excessive current flow in the power source . . .

Fuse

A fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit including the source of power and the load. Its essential component is a metal wire or strip that melts when too much current flows through it Electric fuse is a protective device which protects electrical equipment in th . . .

Uses of the heating effect of current

Electric bulbs work because of the heating effect. A bulb has a long and thin tungsten filament (the curly wire inside). The filament has a higher resistance than ordinary wires. When a current passes through the filament it gets heated and starts to glow. But it does not melt because tungsten has a very high melting point. Electric heater, irons, to . . .

Construction of Fuse

The fuse wire is made of zinc, copper, silver, aluminum, or alloys to provide stable and predictable characteristics. Fuse should be of low resistance and low melting point as per the requirement current rating for overcurrent protection. . . .

Magnetic effect of electric current

The magnetic effect of electric current is known as electromagnetic effect. It is observed that when a compass is brought near a current carrying conductor the needle of compass gets deflected because of flow of electricity. This shows that electric current produces a magnetic effect. . . .

Electromagnet

An electromagnet is a magnet that runs on electricity. A magnet produced by passing an electric current through a coil (a length of wire wound closely together is called a coil) wound around a soft iron core is called an electromagnet. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric cu . . .

Properties of electromagnet

An electromagnet’s strength depends on the number of turns of wire and the amount of current passing through it. An electromagnet is not a permanent magnet. Its magnetism lasts only while a current passes through its coil. Once the current stops, the iron core loses its magnetism. . . .

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