WELCOME

1. WELCOME ELECTRICAL CIRCUIT ELEMENTS : RESISTOR,INDUCTOR,CAPACITOR ELEMENTS OF ELECTRICAL ENGINEERING-(2110005) ACTIVE LEARNING ASSIGNMENT MADE BY:- • VIPAL PATEL-13BECEG007 • VIDHI PATEL-13BECEG005 • KIRTI PARMAR-13BECEG029 • NIKITA RATHOD-13BECEG031 Guided by SAGAR AHIRE Ass. Prof. SVIT, VASAD

2. CERTIFICATE THIS IS TO CERTIFY THAT MR./MISS_________________ ID NO.-___________________________________________________ OF PROGRAMME ____________________________ HAS SATISFACTORILY COMPLETED HIS/HER________________________________________TEAM WORK IN THE SUBJECT OF____________________ CODE_______________FOR THE TERM ENDING IN 20 - 20 STAFF IN CHARGE HEAD OF THE DEPARTMENT DATE:

3. What are resistors? • A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. • I=V/R • The ratio of the voltage applied across resistor’s terminal to the intensity of current in the circuit is called its resistance.

4. An applied voltage across an object causes an electric field across the material. • The electric field accelerates any “free” electrons in the material. This motion is the electric current. • Electrons collide with atoms which slows them down increasing resistance to the current.

5. What factors determine resistance? • The greater the length of an object the more resistance it will have. • The greater the cross sectional area the less resistance it will have. • Resistance = Resistivity * Length / Area

6. What properties affect resistivity? • Some materials (e.g. copper) have lots of free electrons and have low resistivity, (good conductors). • Others (e.g. glass) have almost no free electrons. • Semiconductors (e.g. silicon) have modest numbers. • In a superconductor the electrons don’t ever collide with the atoms so the resistivity is zero.

7. Some real resistors • Commercial resistors are often carbon or metal film. • 6 inches of HB pencil (Carbon) is about 16 Ohms • If we connect 6V across it we get 1 volt per inch • If we connect 12V across it we get 2V per inch (and it catches fire)

8. Ohms Law • For an ideal resistor “R” • The current “I” increases with applied voltage “V” (Electromotive force) • The greater the resistance “R” to the current the less current I flows. • I = V / R • Amps = Volts / Ohms

9. Resistors in series • Our resistors both resist the current. Its like one longer resistor (or pencil). We add the resistances R1 and R2 so: • R = R1 + R2 • I = V / (R1+R2)

10. The Potential divider

11. The Potential divider • Just like in our pencil the voltage will distribute itself proportional to the resistance. • E.G if R1 is twice R2 then 1/3 of the voltage will be across R2. • So V will be 4 volts.

12. The Potential divider • V2 = V1 * R2 / (R1+R2) • (We can prove this from Ohms law) • I = V1/(R1+R2) • I = V2/R2

13. Current Divider • In parallel circuit, current is divided, voltage across each resistor is same. • Total current I I=I1+I2 ……………1 • I=V/R; I1=V/R1; I2=V/R2; • Therefore from 1; • R=R1*R2/R1+R2; • V=I(R1*R2/R1+R2); • I1=R2*I/R1+R2; • I2=R1*I/R1+R2;

14. Resistors in parallel • Our resistors both carry current so its like one thicker resistor. We add the currents so I = V / R1 + V / R2 • From Ohms law we have I = V / R • So: 1 / R = 1 / R1 + 1 / R2 • Or: R = (R1 * R2) / (R1 + R2)

15. What is Inductor? An inductor is a passive electronic component that storesenergy in the form of a magnetic field. Inductors are used with capacitors in various wirelesscommunications applications. An inductor connected in series or parallel with a capacitor can provide discrimination against unwanted signals. RELATED GLOSSARY TERMS:Ohm's Law, reboot (warm boot, cold boot), self-destructing email,shared memory, electron, L1 and L2, permittivity (electric permittivity), cardinality, angular velocity (rotational velocity), SKU (stockkeeping unit)

16. Inductance Inductance is typified by the behavior of a coil of wire in resisting any change of electric current through the coil. Arising from Faraday's law, the inductance L may be defined in terms of the emf generated to oppose a given change in current

17. Inductance of a Coil For a fixed area and changing current, Faraday's law becomes Since the magnetic field of asolenoid is then for a long coil the emf is approximated by From the definition of inductance we obtain

18. Inductance of a solenoid The inductance of a coil of wire is given by

19. Approximate Inductance of a Toroid Finding the magnetic fieldinside a toroid is a good example of the power ofAmpere's law. The current enclosed by the dashed line is just the number of loops times the current in each loop. Amperes law then gives the magnetic field at the centerline of the toroid as

20. Capacitors.

22. What are capacitors? Capacitors are components that are used to store an electrical charge and are used in timer circuits. A capacitor may be used with a resistor to produce a timer. Sometimes capacitors are used to smooth a current in a circuit as they can prevent false triggering of other components such as relays.   When power is supplied to a circuit that includes a capacitor - the capacitor charges up.  When power is turned off the capacitor discharges its electrical charge slowly.

23. How a capacitor works? When the circuit is switched on, the LED emits light and the capacitor charges up. When the switch is turned off the LED stills emits a light for a few seconds because the electricity stored in the capacitor is slowly discharged. When it has fully discharged it's electricity the LED no longer emits light. If a resistor is introduced to the circuit the capacitor charges up more slowly but also discharges more slowly. What will happen to the light ?

24. Capacitors in parallel. The total charge , however, stored in the two capacitors is divided between the capacitors, since it must distribute itself such that the voltage across the two is the same. Since the capacitors may have different capacitances,  and , the charges  and  may also be different. The equivalent capacitance  of the pair of capacitors is simply the ratio , where  is the total stored charge. It follows that 

25. Capacitors in series.  Assuming, as seems reasonable, that these plates carry zero charge when zero potential difference is applied across the two capacitors, it follows that in the presence of a non-zero potential difference the charge  on the positive plate of capacitor 2 must be balanced by an equal and opposite charge  on the negative plate of capacitor 1. Since the negative plate of capacitor 1 carries a charge , the positive plate must carry a charge . Likewise, since the positive plate of capacitor 2 carries a charge , the negative plate must carry a charge . The net result is that both capacitors possess the same stored charge . The potential drops,  and , across the two capacitors are, in general, different. However, the sum of these drops equals the total potential drop  applied across the input and output wires: i.e., . The equivalent capacitance of the pair of capacitors is again . Thus, Giving,

26. Capacitance of a capacitor The capacitance of a capacitor can be defined as the charge separated and stored per unit voltage applied. C = Q/V.  The capacitance measures the ability of a device to store electrical energy in the form of an electric field. Capacitance is the ability to store energy in the form of an electrostatic field. It's energy that is stored between two dielectric (insulated) plates, and measured in Farads (usually microfarads)