Electromagnet

Introduction:-

An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole, denoting the center of the coil. The magnetic field disappears when the current is turned off.

Working of Electromagnet :-

Electromagnets work because when electricity flows through a wire it makes a magnetic field around the wire. The direction of the magnetic field can be found by using the right-hand rule. This means that if a person points the thumb of their right hand in the direction of the current, the magnetic field would go around the wire the same way their fingers would wrap around the wire.

The magnetic field made by a single wire is not usually very strong. To make an electromagnet normally the wire is wrapped in many loops to make the fields of each piece of wire add together into one stronger magnetic field.

Uses of Electromagnet

Uses of Electromagnets

Generators, motors, and transformers
Electric buzzers and bells
Headphones and loudspeakers
Relays and valves
Data storage devices like VCRs, tape recorders, hard discs, etc.
Induction cooker
Magnetic locks
MRI machines

Uses in Home Appliances

Most of the electric appliances used in the home use electromagnetism as the basic working principle. Some electromagnet uses in the home include an electric fan, electric doorbell, induction cooker, magnetic locks, etc. In an electric fan, the electromagnetic induction keeps the motor rotating on and on making the blade of the fan to rotate. Also in an electric doorbell when the button is pressed, due to the electromagnetic forces the coil gets energized and the bell sounds.

Uses in Medical Field

The uses of electromagnets are also seen in the medical field. MRI scan which is short for Magnetic Resonance Imaging is a device that uses electromagnets. The device can scan all the tiny details in the human body with the help of electromagnetism.

Uses in Memory Storage Devices and Computer Hardware

The data in ebook gadgets and phones are stored in the electromagnetic format in the form of bytes and bits. The computer hardware is also having a magnetic tape which works on the principle of electromagnetism. Even in the olden days’ electromagnets had a huge role in the data storage of VCP and VCR.

Uses in Communication Devices and Power Circuits

Without electromagnets, the mobiles and the telephones we used to make phone calls over a long distance could not have taken shape. The electromagnetic pulses and the interaction of the signals make the mobiles and telephones very handy.

These were some application uses of electromagnets. Stay tuned with BYJU’S to learn more interesting Physics concepts with the help of interactive video lessons.

You will need:

Copper wire

Iron Nail- 3-6 inches

Battery

You can use screw driver or bolt in place of iron nail.

Part 1- Wrapping the Iron with Wire

Choose an iron nail or screw as the core.

Pick out a piece of iron that you have around your home, such as a nail, screw, or bolt. Choose an iron item 3–6 inches (7.6–15.2 cm) in length so that there’s plenty of room to wrap the wire around the iron object.

2. Pull a strand of copper wire loose from the spool.

Since you won't know the exact length you'll need until you wrap the iron completely, don't cut the strand of wire from the spool yet. Position the wire so that it's perpendicular to the iron core, making it easy to wrap the wire around it many times.

3.Leave 2–3 in (5.1–7.6 cm) of copper wire loose at the end. Before you start wrapping the wire, leave a strand of wire loose from the iron that will attach to the battery that's about 2–3 inches (5.1–7.6 cm) long.

Position the wire so that it’s perpendicular to the iron core and at one end.

4.Wrap insulated copper wire around the iron going in one direction.

Create an ongoing spiral around the piece of iron to conduct the electricity. Wrap the wire in one continuous strand, going in one direction, so that there’s a strong electrical current.

It's essential that the wire is wrapped in the same direction so the electricity flows in one direction. If you wrap the wire in different directions, the electricity will flow in different directions, and you won't create a magnetic field.

5.Push the wire close together as you’re wrapping it.

Wrap the wire tightly around the iron, forming as many spirals as possible to create the best current. As you’re wrapping, use your fingers to push the loops close together. Continue wrapping and pushing the wire until you get to the end of the iron.^[4]

The more wire you use, the stronger the electrical current, so be careful and use caution when creating your magnet.

6.Wrap the entire nail in wire.

There is no certain number of wraps that you need; just be sure to wrap the entire piece of iron with wire, with the strands of wire pushed right up against each other. Once you've reached the end of the iron, you're finished wrapping.

7.Cut the wire so that the end is roughly 2–3 inches (5.1–7.6 cm) long.

Once you reach the opposite end of the iron core, use wire cutters or sharp scissors to cut off the wire from the rest of the spindle. Cut the second end so that it's as long as the first end, helping the wire tips reach the battery equally.

Part 2- Creating Conductible Ends

8.Remove 1–2 cm (0.39–0.79 in) of insulation from the ends of the wires.

Use wire strippers, sandpaper, or a razor to carefully scrape off the insulation from each end. This will help the wires conduct energy more easily.^[6]

As you remove the insulation, the wire will turn from the copper color of the insulation to the natural silver color of the wire.

9. Curl the ends of the wire to create a small circle. Use your fingers to bend the ends of the wire into a very small circle, about 0.5 cm (0.20 in) in diameter. These circles will touch the center of each end of the battery.^[7]

Curling the ends of the wires helps the battery maintain good contact with the wire.

10. Position the ends of the wires to each end of a D battery. Find a D battery, or a 1.5 volt battery, and place each end of the wire on an end of the battery so they're touching. Place pieces of electrical tape or duct tape over each wire end to hold them in place.

Position one wire end at the negative end of the battery and the other wire end at the positive end of the battery.

11. Test out the magnet while holding the wire onto ends of the battery.

Once you have a good grip on the battery with the wires, test it out! Hold the battery and iron close to a small metal object, such as a paperclip or safety pin. If the nail, screw, or bolt picks up the metal object, the magnet is working.^[9]

If the battery becomes hot, use a small towel to hold the wires to the battery.
When you're finished using the magnet, detach the wire ends from the battery.

Data Collection and Analysis

B.S.Bisht

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