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The flow of charged particles is termed as an electric current. The flow of charge would be continuous in current electricity. An electric current travels from a higher potential to a lower potential.
Electricity or electric current requires a circuit consisting of a closed loop of conductive material. flow. The circuit consists of wires connected end-to-end and moving in the same direction.
When a stream of electrons travels through a conductor, it forms an electric current. Conventionally, it is said that the direction of current (I) is always taken in the opposite direction to the direction of electron or charge flow.
Circuit Components
A circuit consists of conductors (wire), source of power, resistor, switch and load. A circuit starts and terminates at the same point. Copper wire is usually used as the conductor. A switch is used to connect or disconnect a circuit. Resistors control the flow of current in a circuit. A resistor is a passive element, which means it only consumes power but does not produce power. A load in a circuit consumes electrical energy and converts it into other forms such as light, heat, etc. A load can be a light bulb, a fan, etc.
Resistance
The physicist Georg Simon Ohm discovered the connection between the current flow I, which flows in a metallic cable, which has the potential difference between its terminals (ends). He found that the potential difference in volts V between the terminals of a given metal wire in an electrical circuit is directly proportional to the current which flows through it, at constant temperature.
When the flow of an electric current is through a wire or a conductor, then then conductor or wire offers some hindrance to the current and this hindrance is the termed as electrical resistance which is denoted by R. Each material has an electrical resistance and thus the conductors give out heat if current passes through it.
Ohm’s law states that the potential difference across the conductor or wire is directly proportional to the current which flows through a conductor.
The Ohm’s law is given as
V∝I
V=IR
Therefore, Resistance is given as
R=VI
Here,
V = potential difference
I = current
R = resistance
From the above equation, we determine that the resistance is the ratio of potential difference across the conductor to the current flow through it.
Electric charge flows through some materials more easily than through others. Electrical resistance measures how much the flow of that electrical charge is restricted within a given circuit.
Combination Of Circuit
There are two ways of combining circuits which are given here.
Series Combination
Parallel Combination
Series and Parallel combination of Resistors
Series Combination of Resistors
A circuit is said to be in series when the current which flows through the resistors are the same. In series circuits, the voltage across each resistor is different. If a resistor breaks or a fault occurs in a series circuit, the entire circuit is turned off. A series circuit is simpler to set up than a parallel circuit.
The total resistance of a series combination is given as
Advantages:
Series combination is used when many bulbs or lights are used together.
Series combination is safe as the flow of current through the circuit is less.
In series combination, it is easy to switch on or off all the lights or all the devices.
Disadvantages:
One device cannot be switched off separately because all the electrical devices have one switch only.
When one element or component is fused or stops working then other elements of circuit will not work.
All the components do not get the same voltage because in series combination, the voltage gets divided.
Parallel Combination of Resistors
A circuit is said to be in parallel when the voltage across all resistors is the same. In parallel circuits, current is branched and re-joins when the branches meet at a common point. A resistor or other component can be easily connected or disconnected without affecting the other elements in a parallel circuit.
The total resistance of a parallel combination is given as
Advantages:
Single device can be turned on or off separately in parallel combination.
Each electrical device gets equal voltage.
When for any reason one electrical device stops working due to some defect then all other devices do not get affected.
Disadvantages:
Parallel combination is less safe because more current is passed through the circuit.
Parallel combination is tedious to use when thousands of devices or bulbs are to be switched on or off together.
Conclusion
The flow of charged particles is termed as an electric current. The flow of charge would be continuous in current electricity.
An electric current travels from a higher potential to a lower potential.
When the flow of an electric current is through a wire or a conductor, then the conductor or wire offers some hindrance to the current and this hindrance is termed as electrical resistance which is denoted by R.
The Ohm’s law is given as
V∝I
Resistance is given as
R=VI
There are two ways of combining circuits which are given here.
Series Combination
Parallel Combination
A circuit is said to be in series when the current which flows through the resistors are the same.
The total resistance of a series combination is given as
A circuit is said to be in parallel when the voltage across all resistors is same.
The total resistance of a parallel combination is given as
