Hello.
Lets start with magnetic field.
Magnetic field: The space or region surrounding a magnet, in which another magnet experiences a force of attraction/repulsion is called magnetic field.
I. Now lets discuss magnetic field due to a current carrying straight conductor.
Oersted's experiment: Its a simple electric circuit, in which a straight conductor (copper wire) is placed parallel to and over a compass needle. The deflection in the needle changes when the direction...
Hello.
Lets start with magnetic field.
Magnetic field: The space or region surrounding a magnet, in which another magnet experiences a force of attraction/repulsion is called magnetic field.
I. Now lets discuss magnetic field due to a current carrying straight conductor.
Oersted's experiment: Its a simple electric circuit, in which a straight conductor (copper wire) is placed parallel to and over a compass needle. The deflection in the needle changes when the direction of current is changed.
This proves that a current carrying conductor always produces a magnetic field around it. It causes the deflection in the compass.
The magnetic field is directly proportional to the current and inversely proportional to the distance from the wire.
Right-hand thumb rule: It is a convenient way of finding the direction of a magnetic filed in a straight current carrying conductor.
Imagine that you are holding a current carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then, your fore fingers will wrap around the conductor. The direction in which they wrap around it is the direction of the magnetic field.
II. Now we move on to magnetic field due to a current carrying circular coil.
A current carrying circular coil acts as a magnet. At every point of a current carrying circular loop the magnetic field around it would become larger and larger as we move away from the wire and in the same direction within the loop.
If there are n turns in the coil, then the magnetic field produced is n times as large as that produced by a single turn.
Maxwell's corkscrew rule: It is useful to find the direction of a magnetic field in the current carrying circular coil.
Consider you are driving a corkscrew in the direction of the current. The direction of the corkscrew is the direction of the magnetic field.
And finally magnetic field due to a current in a solenoid.
A coil of many circular turns of insulate copper wire wrapped closely in the shape of a cylinder is called a solenoid. When current is flowing through it, it behaves like a bar magnet with north and south poles. The magnetic field inside the solenoid is uniform.
Electromagnet: A strong magnetic field produced inside a solenoid can be used to magnetize a piece of soft iron when placed inside the coil. This is called an electromagnet. It's a temporary magnet.
The strength of the electromagnet depends on the current flowing through the solenoid, no. of turns in the solenoid, closeness of the turns and the length of the coil.
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