Electric Current and Theory of Electricity
What is Electric Current?
The electric current flows in the circuit if potential difference exist. The potential difference is the pressure that cause flow of charge.The flow of charge lead to flow of electric current in the circuit.
The electric current flows from the higher potential towards the lower potential. If the two points in the circuit is at the same potential, the flow of electric charge is zero hence the current is zero.The magnitude of the current depends on the rate of flow of charge from one point to another point in a given circuit.
The conducting material has large number of free electrons that can be moved from one atom to another atom under application of potential energy.
The conducting material has large number of free electrons that can be moved from one atom to another atom under application of potential energy.
Unit of Current
The conducting material has large number of free electrons that can be moved from one atom to another atom under application of potential energy.The flow of electric current in a circuit cause by flow of electrons or charge.
The higher the rate of flow of charge, the higher the current. Let q charge flow in t time,
The current in the circuit
I= q/t
In differential form,
I= dq/dt
Electric current is the ratio of charge transferred in a given period of the time. If one coulomb of charge is transferred in one second from one point to another in the circuit is called the one unit current. The unit of electric current is coulomb per second.This is also known as ampere after the name of physicist Andrew Marie Ampere. The SI unit of electric current is Ampere.
How current flows in a circuit?
In metal, free electrons are available which moves randomly.When the metal is connected to a supply source,the source electron repels the electrons of the metal towards the higher potential of the supply source and all the electrons are drifted to the positive point of the supply source which is at the higher potential.. The flow of electron cause current to flow in the circuit.
The flow of the electric current was previously thought was because of positive charge. Now it has proved that flow of the electric current is caused by drifting of electrons from the lower to higher potential point.The flow of current caused by external field is also known as a drift current.
The direction of the flow of electric current is opposite of the direction of flow of electrons.The current flows from the higher to lower potential point is known as conventional direction of current.
Types of current
Direct current
When the current flows in one direction is called the unidirectional or direct current(DC).
Alternating current
When the current flows in positive and negative direction alternatively in a cycle is called alternating or AC current.
Heating Effect of Current
When the current flows in a circuit having resistance, the heat is dissipated in the resistance. The heat produced in the circuit can be expressed as;
Where,
I = Current in ampere
R = Resistance in Ohms
t = Time in Seconds
Magnetic Effect of Current
Magnetic field is set up around the current carrying conductor. The direction of the magnetic field can be found with the right Hand rule.
If a current carrying conductor is placed in a magnetic field the conductor experience a force.The magnitude of the force depends on the magnitude of the current through the conductor and on the strength of the magnetic field.The Direction of the force can be found by Fleming's Left Hand Rule.
The magnitude of the force can be expressed as;
F= BILSinθ
How current flows in a circuit?
In metal, free electrons are available which moves randomly.When the metal is connected to a supply source,the source electron repels the electrons of the metal towards the higher potential of the supply source and all the electrons are drifted to the positive point of the supply source which is at the higher potential.. The flow of electron cause current to flow in the circuit.
The flow of the electric current was previously thought was because of positive charge. Now it has proved that flow of the electric current is caused by drifting of electrons from the lower to higher potential point.The flow of current caused by external field is also known as a drift current.
The direction of the flow of electric current is opposite of the direction of flow of electrons.The current flows from the higher to lower potential point is known as conventional direction of current.
Types of current
Direct current
When the current flows in one direction is called the unidirectional or direct current(DC).
Alternating current
When the current flows in positive and negative direction alternatively in a cycle is called alternating or AC current.
Heating Effect of Current
When the current flows in a circuit having resistance, the heat is dissipated in the resistance. The heat produced in the circuit can be expressed as;
Where,
I = Current in ampere
R = Resistance in Ohms
t = Time in Seconds
This is known as Joule's Law of heating.
Magnetic Effect of Current
Magnetic field is set up around the current carrying conductor. The direction of the magnetic field can be found with the right Hand rule.
If a current carrying conductor is placed in a magnetic field the conductor experience a force.The magnitude of the force depends on the magnitude of the current through the conductor and on the strength of the magnetic field.The Direction of the force can be found by Fleming's Left Hand Rule.
The magnitude of the force can be expressed as;
F= BILSinθ
Post a Comment
Note: Only a member of this blog may post a comment.