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Topic :- Electricity


Electricity is the energy made available by the flow if electric charges through a conductor. Conductors can be in forms of electrolytes, human body, metal rods, metal plates, metal wires etc.
Electricity is of two types, alternating current (ac) and direct current (dc).
Alternating current is a form of electricity that is unstable, therefore when the human body (which is a natural conductor) comes in contact with an ac-carrying conductor, the vibrations caused by this current to the human body is what we commonly know as "shock".
Direct current is a stable current I.e. it has a stable value and travels on one direction. When the human body comes in contact with a conductor carrying this type if current, no "shock" is experienced as this type of current is stable.
For the alternating current, because if its unstable state, its value is constantly in variation, therefore, to get a single value for this current, we make use of its RMS which us an acronym for RootMeanSquare which is the average value for the set if values this unstable current has at different periods.
Basic terminologies of "ELECTRICITY"
Current: This refers to the flow of electrons via the conductor. Conventional current flow is in a direction opposite to the direction of electron flow I.e. After electrons start flowing in a clockwise direction, then current starts flowing in an anticlockwise direction. Current is denoted by (I) and measured in Amperes (A)
Resistance: This refers to the force that opposes the flow of current. It is measured in Ohms.
Voltage: This is the rate at which energy is drawn from a source that produces a flow of electricity in a circuit. It is measured in volts and denoted by (V). It is also known as electromotive force (emf)/potential difference (pd) between the terminals of a circuit.
It can also be defined as the difference in electrical charge between two points in an electrical circuit.
Circuit: This is the path provided for the flow of electrons. It consists of a power source,conductor,a key and the load.
When the circuit is said to be open, this means that the key is open I.e. There is no current flow in the circuit as there is a break in the electrical circuit.
When the circuit is closed, this means that the key is closed and there is current flow in the circuit.
A short circuit refers to a closed circuit that has no load.
An electrical circuit could also include resistor(s), capacitor(s) and inductor(s).
An inductor provides inductance, a capacitor provides capacitance and a resistor provides resistance.

Some equations of electricity.
V=IR
P=IV
P=I²R
V=I(R+r)
Where V=voltage of the electrical circuit.
I=Current of the circuit
R=External resistance of the circuit
r=Internal resistance of the circuit
P=power of the circuit.


Miscellaneous examples:
An electrical circuit has an internal resistance of 1ohm, a voltage of 15v and a current of 5A, calculate the external resistance.

Solution
V=I(R+r)
R=(V/I)-r
R=(15/5)-1=3-1=2ohms.

The power of an electrical circuit is 20W and the resistance is 5ohms, calculate the current.

Solution
V=I²R
I=√(V/R)=√(20/4)=√4=2A

The current and voltage of an electrical circuit are 10A and 4V respectively, calculate the Power of the circuit.

Solution
P=IV
P=10×4=40W

That will be all on electricity for now. On our next class on electricity, we shall be looking into inductance and capacitance also. Have a nice day.
Forward your word problems on electricity to the group and if you have any other problems, send a DM to any of the admins.


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