Electrical Projects For Beginners

Nikhil Shukla

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© Copyright: V&S Publishers Edition 2017

The Copyright of this book, as well as all matter contained herein (including illustrations) rests with the Publishers. No person shall copy the name of the book, its title design, matter and illustrations in any form and in any language, totally or partially or in any distorted form. Anybody doing so shall face legal action and will be responsible for damages. Printed at Repro Knowledgecast Limited, Thane

Publisher's Note V&S Publishers is pleased to bring out a new book – Electrical Projects For Beginners, that is designed for high school students. The practical work helps the students in understanding the concepts in a systematic and scientific way. The book consists of various projects that help students to learn advanced scientific principles and develop skills in science. Every project has been explained thoroughly describing all important aspects. The book includes several topics such as electromagnetic forces, static electricity, current flow, motors and generators, resistance and capacitances, generating electricity, solid state electronics, and radio frequency energy. The materials required to do projects are commonly available at home or are easily available at minimal cost in the market. The basic idea behind publishing this book is to provide students with the study material which is interesting, educative, and practical. With the help of this book the students can easily do the given projects and can think of doing other projects also. The contents are written in a simple and lucid language for better understanding of the concepts and explanations. Thus, to gain inventive skills you need to go through the given projects, which will definitely prove to be a great learning experience for all of you!

Contents Electrical Projects Battery Combination....................................................................................................................... 9 Bread Board or Plug-in-Board.......................................................................................................11 Brightness of Electric Bulb........................................................................................................... 13 Capacitance of a Capacitor........................................................................................................... 14 Circles of Magnetism.................................................................................................................... 17 Electrical Conductivity................................................................................................................. 19 Electrolysis of Water..................................................................................................................... 21 Electromagnetic Effect.................................................................................................................. 23 Electromagnetic Force.................................................................................................................. 25 Hand Battery................................................................................................................................. 27 Inductance of an Inductor (Coil)................................................................................................... 29 Measurement with Multimeter...................................................................................................... 31 Resistance of a Resistor................................................................................................................ 34 Short Circuit.................................................................................................................................. 36 Static Electricity............................................................................................................................ 38 Transitor Amplifier........................................................................................................................ 40 Wiring of a House......................................................................................................................... 42

Introduction Welcome to the world of experimentation and practical science around us. In fact, science is the knowledge that is obtained through reading, experimentation, observation and realization in a systematic manner. Any performance done systematically is said to have been done scientifically. In short, science means a system which is enjoyable, interesting, and thought-provoking.

Electricity and Electronics There is a very little difference between electricity and electronics. Generally, Electronics is considered to be a branch of Electricity. It deals with electricity since electrons move through electricity and are affected by certain devices like resistors, capacitors, coils, transistors, and integrated circuits. The human race has harnessed electronic power to perform various tasks such as to illuminate a light bulb, make a calculating machine called computer which can do mathematics operations at tremendous speed. Electronics is among the most rapidly changing sciences as various technological advancements are made every year. In homes today you will find a wealth of electronic marvels such as computers, stereos, televisions, radios, telephones, laser music discs, copy machines. Electrical appliances such as washing machines, hair dryers, vacuum cleaners, toasters, microwave ovens, electric can openers, refrigerators, air conditioners etc. have enhanced our standard of living. This book includes many topics and projects based on electromagnetic forces, static electricity, flow of current, motors and generators, resistance and capacitances, generating electricity, solid state electronics, and radio frequency energy. You have to only make your selection, and begin your project. Most of the materials needed to do projects are commonly found at home or are easily available at minimal cost in the market. Some standard symbols used to present various components are shown in Chapter-2.

Aim of Experimental Study An experiment is the base of the development and growth of science. In science the aim of experimentation is to verify a given law which has already been derived from a theory. New discoveries can be made while doing an experiment with open eyes and attentive mind.

Significance of Practical Work in Laboratory Physics is an experimental science. From the past events, we find that most of the path-breaking discoveries have been made by scientists while experimenting on an already known fact. Though the theory is taught in the class, performing an experiment by oneself makes the taught principles

quite clear. It is just like learning by doing. Practical works done in a laboratory provide young minds the systematic and scientific training. To avoid laboratory woks is just like to learn to swim without going to the swimming pool.

Features of the Book This book deals with a wide variety of topics related to Electricity and Electronics. The scientific concepts and projects introduced in the book will help the students to understand advanced scientific principles and develop many skills in science, which are required to sort out everyday problems in our ever-increasing complex society. All the projects are classified into three grades (A, B, and C) for beginners, intermediates, and professionals respectively. In each project, complete theory has been described systematically covering all important aspects. We suggest making a ‘schematic diagram’ of each project, which shows a pictorial layout of an electrical circuit and the arrangement of components and their interconnection. This will enhance your display visually and comprehension as well. The book includes various activities which are useful for beginners and professionals i.e. it covers from the sixth standard to the graduate level.

Project-1 Battery Combination Why is the position of the cell or battery important?

Introduction The device which supplies energy to the circuit is called battery. The flow of current generated by batteries can happen not only between poles of the opposite sign but also on the correct combination of batteries with one another. Cells and batteries may be connected in series, parallel or combinations of both. In series combination, positive terminal of one cell is connected to the negative terminal of another cell. Cells or batteries connected in parallel have their like terminals connected together.

Materials Required Two 1.5 volt batteries, a small bulb, two pieces of electric cable with the ends uncovered, A ruler and sticky tape.

Assembly 1. Stick the two batteries along the length of the ruler with the sticky tape. Follow a positive pole (marked at the positive end with a plus (+) sign and a negative pole marked at the opposite end with a minus (–) sign. 2. Use the sticky tape of stick at the ends of two wires to the opposite heads of the batteries. Bring the two batteries together. Then touch the bulb with free ends of the wires, as shown. 3. Now, reverse the position of the batteries, so that the two positive poles touch. 4. Re-connect the wires to the two ends of the double battery and touch the bulb again,

To Do and Notice The bulb does not light up.

Fig. 1.1 : Circuit Diagram

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Electrical Projects For Beginners

What Happens? In case I when we touch the bulb with free ends, the bulb lights up because the electrons generate an electrical current when they flow continually from negative pole to the positive pole of the battery. Something happnes if two batteries are connected to each other because the electrons still escape from the negative pole on the one hand and go towards the positive pole on the other. In case II the bulb does not light-up because the eletrons escape from both the negative poles. They go against each other and so the current does not flow. This is why an electric torch or toy will not work if a battery is inserted with the poles in wrong positions.

Try It Yourself Take 3 batteries and repeat the same experiment. p

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Project-2 Bread Board or Plug-in-Board How will you connect an LED in a breadboard?

Introduction A breadboard or protoboard is usually a construction base for prototyping of electronics. The terms ‘bread board’ is commonly used to refer to a solderless bread board (plug board). In this experiment you will test how the plug-in board works by lighting up the red lamp provided. It is referred to as a ‘Light emitting diode’ or LED.

Materials Required Plug-in-Board, one 330 Ω resistor, 9V lattern battery, connecting wire, an LED and a wire.

Row X

3 Orange 3 Orange x 10 Brown Gold

Row Y 330 ohm resistor

Plug-in Board

Assembly (1) Plug in 9 V battery, red wire into row X and black wire into row Y. (2) Plug in 330 Ω resistor to pinholder 1-X and 1-C. (3) Plug in the LED to holes 1-E and 1-F (longer leg of the LED should be in 1F) (4) Plug in jumper wire from 1-G to 1-Y.

Fig. 2.1 : Bread Board

To Do and Notice

330Ω +9V LED

Fig. 2.2 : Circuit diagram

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Electrical Projects For Beginners After supplying the current to the Ckt, the red light comes ON? If not, you plug in the LED again. The long leg of LED should be in 1-F and small leg in 1-E. Now, you see that the red light of LED comes ON.

What Happens? A diode conducts electricity in one direction because it has a polarity of LED. You have to pay attention to which side of LED goes to (+) and which to (–) on the battery. The other important thing in this experiment is resistor. Resistor is called a ‘current limiter’ because it limits the flow of current or electricity in the circuit. In this experiment the resistor is needed to resist the flow of electricity. If you don’t use it, too much electricity flows through the LED, causing it to burn out.

Try It Yourself Can you connect two-colour LEDs in place of a simple LED?

Hint: Two-colour LEDs have two anodes (+), and one cathode (–) p

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Project-3 Brightness of Electric Bulb What does the brightness of light depend on?

Introduction The brightness of a light depends on the speed with which the electrical charge flows through the conducting wires. If the path of the charges goes long, the brightness of bulb decreases. As wire goes long, the resistance of overall circuit increses so that the power loss also increases and net voltage across the terminal of bulb decreases due to decrease in this brightness.

Materials Required A 4.5V battery, a bulb with bulb-holder, electric cable, a pencil lead and sticky tape.

Assembly 1. Connect the wire to the battery and the bulb 2. Open up the pencil. Take out the lead. 3. Fix the end of the wire to one end of the lead. Run the end of the other wire along the length of the lead. Principle : Many electrical appliances which we use in our homes have an electrical resistance inside them, which heats up with the passage of the current and changes electrical energy into thermal (heat) energy.

To Do and Notice When the end of the wire is run along the length of the lead, the light in the bulb varies in brightness.

What Happens?

Fig. 3.1 : Circuit Diagram

The lead offers resistance to the passage of electrical current. The longer the length of the lead which is a part of circuit, the more the energy which is absorbed, and the less the brightness of the bulb.

Try It Yourself Take an ammeter and measure the current passing to the bulb. p

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Project-4 Capacitance of a Capacitor How do you find the value of unknown capacitance in a circuit?

Introduction The charge-holding property of a body is called capacitance or capacity of a capacitor. A capacitor essentially consists of two conducting surfaces separated by an insulating material. It has the property to store electrical energy in the form of electrostatic charge. Using De Sauty Bridge we measure an unkown capacitance in terms of a standard capacitance i.e. comparing two capacitances. Two ratio arms of this bridge consists of pure resistors and rest two consist of capacitors where one is of unknown value and the other is standard capacitor.

Materials Required 1. 2. 3. 4. 5.

Audio Frequency generator Decade Resistance boxes Decade capacitance box Head Phone set Unknown capacitor

Assembly De Sauty’s Bridge can be used to measure the value of capacitor. This bridge is very simple. Let C1 = Cx = Unknown capacitor

C2 = A standard capacitor

R1, R2, R3, R4, are standard resistances

At bridge balance conditon.

C1/C2 = R2/R4 = R1/R3 (or) Cx/C2 = R1/R3 and R2/R4 = R1/R3

Bridge balance can be obtained in two ways: (i) keeping C1, C2 constant and varying R1 or R3 (ii) keep the values of R1, R2, R3, R4, so that R1/R3 = R1/R4 is satisfied and vary the capacitor C2. The value of unknown capacitance is found by using the formula. Cx = C2 R1/R3

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Capacitance of a Capacitor B

cc2 1 R1 R2 A

C

Head phone

c1= c2 R3 R4 D AF generator

1 KHz

Fig. 4.1 : Circuit Diagram of De Sauty’s Bridge

1. Connections are made as shown in the circuit diagram. 2. Arrange the values of resistances R1, R2, R3, and R4 so that the condition R1/R3 = R2/R4 is satisfied. 3. Apply a sinusoidal signal of fixed amplitude and fixed frequency of 1 KHz using A.F. generator (A.F.O.) between terminals A and C. 4. The capacitance value of C2 is varied to obtain bridge balance condition. i.e. at this condition minimum sound is heared from head phones or ear phones. 5. Note down the values of R1, R2, R3, R4 and C2 in the table. 6. Repeat the same procedure for different sets of values of R1, R2, R3, R4 and C2 7. Calculate the unknown capacitance using the formula given in the table.

To Do and Notice S. No.

R1 (Ω)

R2 (Ω)

R3 (W)

R4 (Ω)

C2 (μf)

1 2 3 4 5 6

100 100 50 200 600 300

200 200 100 400 200 400

100 50 50 5.0 300 150

200 100 100 100 100 200

0.08 0.04 0.08 0.02 0.04 0.04

Fig. 4.2 : Average value (Cx) = 0.08uf

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Cx = C2R1/R3 (μf) 0.08 0.08 0.08 0.08 0.08 0.08