lOMoARcPSD|35510354 Physics Investigatory Project 2 Project Work (MIT School of Distance Education) Studocu is not sponsored or endorsed by any college or university Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 PHYSICS INVESTIGATORY PROJECT NEW GREEN FIELD PUBLIC ACADEMY SESSION 2022-23 CLASS-XII TOPIC: APPLICATIONS OF SELF-INDUCATANCE SUBMITTED BY: ARHAT RAMPURIA SUBMITTED TO: Mr. RAHUL RATHOR Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 CERTIFICATE This is to certify that Arhat Rampuria of New Green Filed Public Academy has completed the Investigatory Project in Physics titled “Study of Applications of Self-Inductance” himself under the supervision and guidance of Physics Teacher Mr. Rahul Rathor during the year 2022-23. 1.) Internal Examiner 2.) External Examiner Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 ACKNOWLADGEMENT First of all, I am deeply thankful to my Physics teacher Mr. Rahul Rathor for extending his valuable and scholarly guidance throughout the preparation of this project. I am also thankful to all my respected teachers, library staff, office staff and staff members of the Physics Laboratory of the school. I am also thankful to the teachers and staff members of the department of Physics for extending their humanitarian and scholastic assistance in finding out the solutions of some query during my work. Last but not the least I am indebted to my friends, classmates and parents for encouraging and never let me down in my confidence while completing the project. INTRODUCATION Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 What is self-inductance? •When an electric current is passed through an insulated conducting coil, it gives rise to a magnetic field in the coil so that the coil itself behaves like a magnet. •The magnetic flux produced by the current in the coil is linked with the coil itself. •As the strength of the current in the coil is changed, the flux linked with the coil also changes. Under such circumstances an emf is induced in the coil too. Such emf is called a self-induced emf and this phenomenon is known as self-induction. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 AIM:To study the factor on which the self inductance of a coil depends by observing the effect of this coil, when put in series with a resistor (bulb) in a circuit fed up by an A.C. source of adjustable frequency. APPARATUS:A coil of large turns, a.c. source of adjustable frequency, an electrical bulb , (6V) a.c. ammeter of suitable range rheostat , a soft iron rod, one way key, connecting wires etc. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 THEORY:Self inductance is the property of a coil which opposes the change in current through it. The self inductance of a coil (long solenoid) is L= µ0 µrN2A/ l Where µr, = Relative magnetic permeability of magnetic material, µr = µ/ µ0 N = Total number of turns in solenoid A = Area of cross-section of solenoid l= length of solenoid. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Hence, the self inductance depends upon: 1. No. of turns (N), Lα N² 2. Geometry of coil, Lα A, L α(1/l) 3. Nature of core material, Lα µ When an inductor is connected in series with a resistor (bulb) with a variable source of frequency, then current flowing in the bulb is Irms = Erms/Z Where, Z = √ R2 + ω2 = Impedance of the a.c. circuit. Here R= Resistance of the bulb L = Self inductance of coil ω = 2πf = Angular frequency of a.c. source Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 CIRCUIT DIAGRAM :- PROCEDURE:1. Make all connections as shown in the circuit diagram. 2. Switch on the a.c. supply & adjust the current in the circuit by using the variable resistor (Rh). Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 3. Record the current in a.c. ammeter & seethe brightness of bulb. 4. Now, put the soft iron rod inside the conductor core & record the current in a.c. ammeter & again check the brightness of bulb. The current & brightness both decreases. 5. Now, switch off the supply & decrease the frequency of a.c. source (say 50 Hz). 6. Again switch on the supply & adjust the current in circuit at same constant voltage 6 V by using the rheostat. Note the current in ammeter & brightness of bulb. The current & brightness both will increase. 7. Again insert the iron rod in the core of coil & note the current & brightness. The current & brightness both decreases. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 8. Repeat the steps 5, 6 and 7 for different frequency of a.c. source. OBSERVATIONS:1. Least count of ammeter = 0.05 A. 2. Zero error of ammeter = 0 A. 3. Range of ammeter = 0 – 5 A Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 RESULT :1. The current in the circuit decrease on inserting the iron rod in the core of coil at constant frequency of applied voltage &brightness of bulb decreases & vice-versa. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 2. The current in the circuit increases on decreasing the frequency of applied voltage & vice-versa. Therefore, the brightness of bulb increases. PRECAUTIONS:1. The coil should have large number of turns. 2. Current should be passed for a small time to avoid the heating effect. SOURCES OF ERRORS :1. The resistance of circuit may increases lightly due to heating effect of current. 2. There may be eddy current in soft iron coil. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Applications of Self-Inductance There are many applications of self inductance, one of the major ones being a tesla coil, What is a tesla coil A Tesla coil is a radio frequency oscillator that drives the air-core double-tuned resonant transformer to produce high voltages with low currents. To understand better, let’s define what is a radio frequency oscillator. Primarily, we are aware that the electronic oscillator is a device that produces electrical signals of either a sine wave or a square wave. This electronic oscillator produces signals in the radio Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 frequency range of 20 kHz to 100 GHz, known as a radio frequency oscillator. Tesla Coil Working Principle This coil has the ability to produce output voltages up to several million volts based upon the size of the coil. The Tesla coil works on a principle to achieve a condition called resonance. Here, the primary coil emits huge amounts of current into the secondary coil to drive the secondary circuit with maximum energy. The fine-tuned circuit helps to shoot the current from primary to secondary circuit at a tuned resonant frequency. Tesla Coil Circuit Diagram This coil has two main parts – a primary coil and a secondary coil, with each coil having its own capacitor. A spark gap connects the coils and capacitors. The functionality of the spark Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 gap is to generate the spark to excite the system. Tesla Coil Working This coil uses a specialized transformer called a resonant transformer, a radio-frequency transformer, or an oscillation transformer. The primary coil is connected to the power source and the secondary coil of a transformer is coupled loosely to ensure that it resonates. The capacitor connected in parallel with the transformer circuit acts as a tuning circuit or an LC circuit to generate signals at a specific frequency. The primary of the transformer, otherwise referred to as a resonant transformer steps up to generate very high levels of voltage ranging Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 between 2kv to 30 kV, which in turn charges the capacitor. With the accumulation of massive amounts of charge in the capacitor, eventually, breaks down the air of the spark gap. The capacitor emits a huge amount of current through the Tesla Coil (L1, L2), which in turn generates a high voltage at the output. Oscillation Frequency The combination of a capacitor and primary winding ‘L1’ of the circuit forms a tuned circuit. This tuned circuit ensures that both primary and secondary circuits are finely tuned to resonate at the same frequency. The resonant frequencies of the primary ‘f1’ and secondary circuits ‘f2’ and are given by, f1=1/2π√L1C1 and f2=1/2π√L2C2 As the secondary circuit cannot be adjusted, the moveable tap on ‘L1’ is used to tune the primary circuit till both the circuits resonate at the same frequency. Therefore, the frequency of the primary is the same as the secondary. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 f = 1/2π√L1C1 =1/2π√L2C2 The condition for primary and secondary to resonate at the same frequency is, L1C1= L2C2 The output voltage in the resonant transformer does not depend on the number-of-turns ratio as in ordinary transformer. As soon as the cycle begins and as the spar sets up, the primary circuit’s energy is stored in the primary capacitor ‘C1’ and the voltage at which the spark breaks down is ‘V1’. W1=1/2C1V12 Similarly, the energy at the secondary coil is given by, W2=1/2C2V22 Assuming there is no loss of energy, W2 = W1. Simplifying the above equation, we get V2 = V1√C1/C2 = V1√L2/L1 In the above equation, the peak voltage can be achieved when air breaks down do not occur. The peak voltage is the voltage at which the air breaks down and begins to conduct. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Advantages/Disadvantages of Tesla Coil The advantages are Allows uniform distribution of voltage throughout the winding coils. Builds up the voltage at a slow pace and hence no damage. Great performance. The use of 3-phase rectifiers for higher powers can offer tremendous load sharing. The disadvantages are Tesla coil poses several health hazards due to high voltage radio frequency emission that includes skin burn, damage to the nervous system and heart. Involves high costs in buying large DC smoothing capacitor. Construction of circuit consumes much time as it needs to be perfect to resonate Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Applications of Tesla Coil At present, these coils do not require large complex circuits to produce high voltage. Nevertheless, small Tesla coils find their applications in a range of sectors. Aluminium welding Cars use these coils for the spark plug ignition Created Tesla coil fans, used to generate artificial lighting, sounds like music Tesla coils in Entertainment and Education industry are used as attractions at electronics fairs and science museums High vacuum systems and arc lighters Vacuum system leak detectors 1). What do Tesla coils do? This coil is a radio frequency oscillator that drives a resonant transformer to generate a high voltage at low current. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 2). Can a Tesla coil charge a phone? Nowadays, smartphones are released with built-in wireless charging, which uses the principle of a Tesla coil. 3). Is Tesla coil dangerous? The coil and its equipment are very dangerous as they produce very high voltages and currents which cannot be ensured by the human body 4). Why do tesla coils make music? Generally, this coil converts air around it into a plasma that changes volume and causes the waves to spread across all the directions, creating sound/music. This happens at a high frequency of 20 to 100 kHz. 5). How did Tesla transmit electricity wirelessly? A spark gap is used to connect the capacitors and two coils. As the power is fed in through a transformer, it produces the necessary current and powers the entire circuit. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Thus, this is all about an overview of the Tesla coil that can be used to generate electricity of high voltage, low current, and high-frequency. Tesla Coil has the ability to transmit electricity wirelessly up to several kilometres. We ensured that this article gives the reader insights into the working of the Tesla coil, advantages and disadvantages, and applications. Truly, his invention of wireless transmission of electric energy has changed the way the world communicates. Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Bibliography Sites used: https://www.elprocus.com/what-is-tesla-coilcircuit-diagram-working-its-applications/ https://www.slideshare.net/karan_19951/selfinductance-40498923 Ncert class 12 Textbook Physics Lab Manuel Downloaded by Random Apple (bavanikathir79@gmail.com) lOMoARcPSD|35510354 Downloaded by Random Apple (bavanikathir79@gmail.com)
