Class 10 Science – What is Electromagnet? Magnetic Effect of Current
In this article, we will study the topic Electromagnet, How electric motors work? and Law of Electromagnetic Induction from chapter Magnetic effect of current, out of Class 10 Science.
What is Electromagnet?
The electromagnet is formed by the use of a strong magnetic field inside the solenoid to magnetize the magnetic material. Such material can be a soft iron.
- With the increase in electric current, the magnitude of the magnetic field also increases and vice versa.
- With an increase in distance, the magnitude of the magnetic field decreases and vice versa.
- Magnetic field lines are always parallel.
- No two lines intersect each other.
Force on a current carrying conductor in a magnetic field
As per the Andre Marie Ampere (1775-1836), the magnet exerts the equal and opposite force on the current carrying conductor. This is illustrated in below diagram.
In the diagram, the rod experiences the force when it is placed in a magnetic field in a perpendicular direction to its length.
When the direction of current through the conductor is reversed, the direction of extended force will be reversed.
When the direction of the field is changed by changing the two poles of the magnet, the direction of exerting force will change.
Left-Hand thumb rule
According to this rule, when we stretch thumb, forefinger and middle finger of the left hand, the forefinger and middle finger represent the direction of a magnetic field and the thumb points in the direction of the force acting on the conductor.
It works on the basis of the left-hand rule. By using an electric motor, the electric energy is converted into a mechanical energy.
How electric motors work?
In the motor, the rectangular coil is suspended between two poles of a magnetic field. The electric supply to the coil is connected with an accumulator.
When current is passed to the coil, it gets deflected because of the magnetic field. The current reaches the halfway and spilt rings reverse the current direction and the direction of the force acting on a coil also reverses.
When current moves towards another half, the change in direction of force pushes the coil. The coil completes the one rotation and this process keeps the motor in the rotation.
Law of Electromagnetic Induction
This law was founded by Michael Faraday. As per the law, the conductor is set to move inside a magnetic field when an electric current is induced into it.
The galvanometer is the instrument used to detect the presence of a current in the conductor. If the point of it is at zero, it means there is no current. The pointer reflects the direction of current deflecting either right or left.
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Tag: Electromagnetic, Electric Motor, Law of Electromagnetic Induction, Galvanometer, Class 10 science