Atom ahappyfamily by Soujanyaa

Resources | Electronics for young innovators Electrical Current All materials are made up from atoms, and all atoms consist of protons, neutrons and electrons. Protons, have a positive electrical charge. Neutrons have no electrical charge while Electrons, have a negative electrical charge. Atoms are bound together by powerful forces of attraction existing between the atoms nucleus and the electrons in its outer shell. Electrons are attracted towards the nucleus (protons + neutrons). When isolated from the nucleus the electrons exert a potential of attraction called potential difference. When there is closed circuits [i.e; there is a wire a between its positive and negative node], the free electrons start moving and drifting back to the protons due to their attraction, thus creating a flow of electrons. This flow of electron is called Electrical current. Electrons do not flow freely through the circuit as the material they move through creates a restriction to the electron flow. This restriction is called resistance.

Symbol for

Resistance s Re

nc ista e

The Resistance, ( R ) of a circuit is its ability to resist or prevent the flow of current (electron flow) through itself making it necessary to apply a greater voltage to the electrical circuit to cause the current to flow again. Resistance is measured in Ohms, Greek symbol ( Ω, Omega ) with prefixes used to denote Kilo-ohms ( kΩ = 103Ω ) and Mega-ohms ( MΩ = 106Ω ). [ Note : Resistance cannot be negative in value only positive.] designed & conducted by Soujanyaa and Priya, Chlorophile © 2014

Resources | Electronics for young innovators Conductor joyride!! a conductor is an object or type of material that permits the flow of electrical current in one or more directions. For example, a wire is an electrical conductor that can carry electricity along its length.

Insulator

STOP!!! ???

An electrical insulator is a material whose internal electric charges do not flow freely, and therefore make it very hard to conduct an electric current under the influence of an electric field. Some materials such as glass, paper and Teflon, which have high

Voltage, ( V ) is the potential energy of an electrical supply stored in the form of an electrical charge. It is measured in Volts.

oltage CV

Symbol for

Electrical Voltage

Symbol for

resistivity, are very good electrical insulators.

tage Vol C A

It is the force that pushes the electrons to move through a conductor and the greater the voltage the greater is its ability to “push” the electrons

AC and DC source

through a given circuit. As energy has the ability

There are two types of electrical signals , those

to do work this potential energy can be described

being alternating current (AC), and direct current

as the work required in joules to move electrons

(DC).

in the form of an electrical current around a circuit from one point or node to another.

With alternating current, the direction electricity

The difference in voltage between any two

flows throughout the circuit is constantly reversing.

points, connections or junctions (called nodes)

You may even say that it is alternating direction.

in a circuit is known as the Potential Difference, (

The rate of reversal is measured in Hertz, which is

p.d. ) sometimes called the Voltage Drop.

the number of reversals per second. So, when they say that the US power supply is 60 Hz, what they mean is that it is reversing 120 times per second (twice per cycle). With Direct Current, electricity flows in one direction between power and ground. In this arrangement there is always a positive source of

[ Note : Most basic electronic circuits use DC electricity.]

Resources | Electronics for young innovators Electrical Current

charge and is measured in Amperes, symbol i, for intensity). It is the continuous and uniform flow (called a drift) of electrons (the negative particles of an atom) around a circuit that are being “pushed” by the voltage source. In reality, electrons flow from the

Symbol for

Electrical Current, ( I ) is the movement or flow of electrical

ec El

tric Current

negative (-ve) terminal to the positive (+ve) terminal of the supply and for ease of circuit understanding conventional current flow assumes that the current flows from the positive to the negative terminal. Generally in circuit diagrams the flow of current through the circuit usually has an arrow associated with the symbol, I, or lowercase i to indicate the actual direction of the current flow. However, this arrow usually indicates the direction of conventional current flow and not necessarily the direction of the actual flow.

scribble

Worksheet | Electronics for young innovators Activities Read resistance of the provided resistors and write the colour of the bands of each resistor with the value of resistance against it. _______________________________________________________________________________________________ _______________________________________________________________________________________________ _______________________________________________________________________________________________ _______________________________________________________________________________________________ Measure the voltage on the given battery. _______________________________________________________________________________________________ _______________________________________________________________________________________________ In the given circuit, find the defective component. _______________________________________________________________________________________________

Questions 1.

What is the purpose of the switch in the following diagram?

Battery

LED

Switch

_______________________________________________________________________________________________ _______________________________________________________________________________________________ 2.

What difference will it make if the switch is located in either of these two alternate locations in

the circuit?

_______________________________________________________________________________________________ _______________________________________________________________________________________________

designed & conducted by Soujanyaa and Priya, Chlorophile ÂŠ 2014

Worksheet | Electronics for young innovators 4.

Use a multimeter to test the state (Open/Closed) of the provided switch.

_______________________________________________________________________________________________ 5.

Identify the three different types of elementary” particles inside an atom, their electrical

properties, and their respective locations within the atom. _______________________________________________________________________________________________ _______________________________________________________________________________________________ _______________________________________________________________________________________________ 6.

What is happening when two objects are rubbed together and static electricity results?

_______________________________________________________________________________________________ 7.

Explain what the electrical terms voltage, current, and resistance mean, using your own words.

_______________________________________________________________________________________________ _______________________________________________________________________________________________ _______________________________________________________________________________________________ 8.

Describe what “electricity” is, in your own words.

_______________________________________________________________________________________________ _______________________________________________________________________________________________ 9.

Write the name of materials that have good conductivity and bad conductivity (good resistance)

on the chart below.

good

10.

bad

If you are camping in Kibber Wildlife sanctuary and there is no electric power service. Determine

at least three different ways you could generate electrical power to supply the electric power needs at the camp. _______________________________________________________________________________________________ _______________________________________________________________________________________________ _______________________________________________________________________________________________ _______________________________________________________________________________________________ 11.

Why are wires coated with rubber not with cloth?

Worksheet | Design for young innovators

designed & conducted by Soujanyaa and Priya, Chlorophile ÂŠ 2014

Worksheet | Biology for young innovators

designed & conducted by Soujanyaa and Priya, Chlorophile ÂŠ 2014