The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
Introduction
We haven’t seen it, but we have felt its presence due to all the smaller or bigger gadgets that we use in our everyday lives. Did you guess it? Yes, it’s electric current!
Here, we will talk about the electric current that is our regular need. We can’t even think of our lives without it. Below are the basics of electricity and the electric current that you must know. Let’s go through it.
We know there is something in these wires that is continuously flowing and providing us with the electricity.
Electric current is the rate of continuous and random flow of electrons at any given point in the circuit. In short, the flow of electric charge is current. Electric current, having SI unit ampere(A), can be measured as the net flow over a region by an instrument called an ammeter.
The electric circuit is the path for these particles to flow. The circuit path has an opening as ‘source’ and closing as ‘earth ground’. It can be a device, battery, or generator.
The whole atom consists of 3 elements distributed in two regions, the inner and orbital. Protons, neutrons, and electrons are the three basic particles in an atom. Proton elements containing the positive charge lie in the nucleus along with the neutral charge element neutron. Thus the centre part of the atom, which is the nucleus, has a positive charge. Negatively charged electrons revolve in the orbits around the nucleus in the centre.
You can calculate the atomic mass of any element by knowing the number of protons or neutrons in it. The same mass particles Protons and neutrons weigh approximately about 1.67 × 10-24 grams. Thus neutrons having no charge contribute to atomic mass but not to atomic charge. Electrons have 9.11 × 10-28 grams weight, which is only 1/1800 of an atomic mass unit.
There are materials that we know on wearing that help us against electric current. On the contrary, some materials are very good for electricity to flow and get a good current.
Conductors are those materials that allow easy electron flow in them and transfer charge through it. On providing charge to a precise location on conducting material, it spreads over the whole surface as the electron flows and charge is transferred. The charge can also be passed to another conducting material on bringing them in contact.
While Insulators, opposite to it, are the materials that resist this movement of electrons in free space. The given charge at any location on the insulating material remains there only and does not spread over completely.
The model described in the form of a mathematical expression, or setting the equivalent device in the manner that it behaves as the required one for the electrical circuit, is known as the electrical model.
There are various ways to explain this using numerous devices and tricks for the classroom or anywhere.
Drift Velocity is the average velocity attained by charged particles (electrons) in a material due to an electric field. The average velocity mostly results in zero because of the random direction movement of electrons. On applying an electric field, these randomly moving electrons slowly align in one direction. Thus drift velocity is the velocity at which electrons are brought in the same direction.
I=nAvQ
where
I is current,
N is the number of electrons,
A is the cross-sectional area of the conductor,
V is drift velocity, and
Q is the charge.
An electrical circuit is a complete path for the electron to flow – starting from the source from where it enters to the earth ground or return point where it leaves the circuit. The whole path in between these two points is known as load.
The electric circuit can use either AC or DC power sources. It can be as simple as lighting a bulb or complicated as a microprocessor in a computer with various elements such as resistors, capacitors, transistors, and much more.
Electrical circuits can mainly be of four types:
1) Series Circuit: The current in the path of the circuit remains constant as there is only one way to flow.
2) Parallel Circuit: The current gets distributed as there is more than one way for the current to flow.
3) Open Circuit: They have one end of the circuit open and thus current cannot flow continuously or return to the source point.
4) Closed Circuit: They provide a closed path for current to flow between two ends.
To explain the relationship between resistance, voltage, and current, Ohm’s law states that the current through a conductor is directly proportional to the voltage across the conductor. This means that as the current in the circuit increases due to less resistance, voltage gradually increases.
The formula is
Voltage= Current×Resistance
or
V = I×R
where
V = voltage,
I = current, and
R = resistance
Resistance has SI unit ohms and is denoted by Ω.
The basic application for this law is to determine either of these 3 quantities when the other two are provided for any given linear circuit.
The rate at which the energy is consumed in any circuit is known as Electric Power. On the variation of time, power also varies. At any instance of time, the amount of power is known as instantaneous power. Power is the product of Voltage (V) and current (I) for any given circuit or component.
P = V x I
From this equation, it is sure that power can only be obtained when both voltage and current are present, not keeping open or closed circuits condition into consideration.
At a glance, the electric current is the flow of charges that we cannot see, but can surely feel it’s presence and thus the various quantities and components that are related to it need to be understood concisely through different ways.
Getting this all explained only through reading seems quite confusing, doesn’t it? You can go through the explanatory videos and animations on MSVGo. Check out the videos there and get a detailed understanding of the concepts behind them.
