Magnetic Effects of Electric Current
A current flowing in a conductor produces a magnetic field. A compass needle shows deflection when placed near a current carrying conductor. Electric current produces magnetic effect and magnetic field. Magnetic field is space around a magnet in which its force can be experienced. Magnetic field has both magnitude as well as direction.
Field lines are used to represent magnetic field around a magnet. A field line is the path along which a hypothetical free north pole would tend to move.
A metallic wire carrying an electric current has magnetic field associated with it. The field lines about the wire consist of a series of concentric circles whose direction is given by right-hand rule.
In a circular loop, magnetic field at a point in the loop can be represented by a circle. At the centre of the loop the field is almost straight. If the number of turns in the coil is increased, the magnitude of field increases.
A solenoid is formed when coil of many circular turns of insulated copper wire is wrapped closely in shape of a cylinder. Magnetic field due to solenoid is similar to that due to bar magnet. A magnetic material, like soft iron when kept inside the solenoid, the material gets magnetized and is called an electromagnet.
When a current carrying conductor is placed in a magnetic field, it experiences a force due to magnetic field. The direction of force can be found by Fleming’s Left-Hand Rule. This rule is helpful in finding the direction of force in the devices such as electric generator, electric motor and many measuring devices.
Electromagnetic Induction is a process in which a changing magnetic field in a conductor induces a current in another conductor. The direction of induced current can be found by Fleming’s Right-Hand Rule.
The concept of electromagnetic induction was first studied by an English physicist Michael Faraday. His discovery made an important advancement in science as it was successful in generating electric currents using electric generators.
The generated electricity is transported to our homes using cables. The main supply in our homes is supported either through overhead electric poles or by underground cables. Safety is an important aspect while using electricity. As a safety measure an earth wire and electric fuse is used in domestic circuits.