Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Rc and rl circuits


Published on

sa mga students ni Sir Jemay :D

Published in: Technology, Business

Rc and rl circuits

  1. 1. RC Circuits Charging CapacitorThe capacitor is neutralNo current flows through the circuit
  2. 2. RC Circuits Charging CapacitorThe switch is closedMaximum current flows
  3. 3. RC Circuits Charging Capacitor +q -q +q +q goes to lower part of capacitor +q is repelled from upper part of capacitor leaving a -q chargeAs the lower plate increases in + charge, current decreases due torepulsion
  4. 4. RC Circuits Charging Capacitor +q -Q +Q +q +qThis process repeats until the capacitor gains and emf equal toand plates with charges +Q and -QFinally, the current is zero due to maximum charge repulsion
  5. 5. RC CircuitsCharging Capacitor-Q+Q
  6. 6. RC Circuits Charging CapacitorWe can write Kirchhoff’s Loop Rule
  7. 7. RC Circuits Charging CapacitorWe can write Kirchhoff’s Loop Rule
  8. 8. RC Circuits Charging Capacitor A differential equation!You need better Calculus skills :’(
  9. 9. RC Circuits Charging CapacitorSolution is quite easy!
  10. 10. RC Circuits Charging CapacitorThis means, at t = 0 seconds, charge incapacitor is zero.As time passes by, charge in the capacitorincreases up till C
  11. 11. RC Circuits Charging Capacitor2nd equation means.. current in the circuit isinitially maximum! and then as time passes by,it goes to zero once the capacitor is fullycharged!
  12. 12. RC CircuitsCharging Capacitor
  13. 13. RC Circuits Discharging CapacitorCapacitor is fully charged at its platesSwitch is open, no current flows
  14. 14. RC Circuits Discharging CapacitorSwitch is closedCapacitor is being dischargedCurrent flows
  15. 15. RC Circuits Discharging CapacitorCapacitor is fully dischargedNo more current flows
  16. 16. RC Circuits Discharging CapacitorWe can write Kirchhoff’s Loop Rule
  17. 17. RC Circuits Discharging CapacitorWe can write Kirchhoff’s Loop Rule
  18. 18. RC Circuits Discharging Capacitor A differential equation!You need better Calculus skills :’(
  19. 19. RC Circuits Discharging CapacitorSolutions are Easy! Charge in capacitor decreases with time! Current also decreases with time!
  20. 20. In Summary!Charging Discharging
  21. 21. SeatworkFind(a) the time constant of the circuit and(b) the maximum charge on the capacitor afterthe switch is closed.(c) If the switch is closed at t = 0, find thecurrent in the resistor 10.0 s later.
  22. 22. RL Circuits Current GrowthOn a 1 whole sheet of paper(a) What is the initial battery current immediately after switch S is closed?(b) What is the battery current a long time after switch S is closed?
  23. 23. RL Circuits Current GrowthThe switch is openNo current flows through the circuit
  24. 24. RL Circuits Current GrowthThe switch is closedCurrent flows through the circuit but is delayed by inductor
  25. 25. RL Circuits Current GrowthWe can write Kirchhoff’s loop rule
  26. 26. RL CircuitsCurrent Growth at t = 0 current starts at zero increases as time passes
  27. 27. RL Circuits Current DecaySwitch S1 is closed, S2 is openCurrent flows through RL circuit through S1.After sometime, the current becomes maximum
  28. 28. RL Circuits Current Decay S1Switch S1 is opened, S2 is closedCurrent flows through RL circuit through S2.
  29. 29. RL Circuits Current Decay S1The current decreases but the diminishing rate is reduced by thepresence of the inductor.
  30. 30. RL Circuits Current Decay S1We can write Kirchhoff’s Loop Rule
  31. 31. RL CircuitsCurrent Decay Current decreases as time passes but not instantaneously zero! This is due to the inductor. “Resists Change”
  32. 32. Seatwork
  33. 33. 12345
  34. 34. LC Circuits
  35. 35. LC Circuits
  36. 36. LC Circuits
  37. 37. LC Circuits
  38. 38. LC Circuits
  39. 39. LC Circuits
  40. 40. LC CircuitsOscillating chargeOscillating current frequency of oscillation
  41. 41. LC CircuitsExampleThe capacitor is initially charged whenswitch S1 is open and S2 is closed. SwitchS1 is then thrown closed at the sameinstant that S2 is opened, so that thecapacitor is connected directly across theinductor. (a) Find the frequency ofoscillation of the circuit.
  42. 42. AC Circuits
  43. 43. Effective Voltage and Current
  44. 44. Effective Voltage and Current
  45. 45. Seatwork1. An LC circuit consists of a 20.0-mH inductor and a 0.500-µF 1a: 10k rad/s 1b: 20 V capacitor. If the maximum instantaneous current is 0.100 A 2.608. pF (a) What is the frequency of current oscillation? 3.a 134.8 Hz 3.b. 119 uC (b) What is the greatest potential difference across the 3.c. 0.101 A capacitor? 4.200*2^(0.5) cos(2 pi 100 Hz t) Volts 5.a 193 ohms 5.b 145 ohms2. A fixed inductance L = 1.05 µH is used in series with a variable capacitor in the tuning section of a radio. What capacitance tunes the circuit to the signal from a station broadcasting at 6.30 MHz?3. An LC circuit contains an 82.0-mH inductor and a 17.0-µF capacitor that initially carries a 180-µC charge. The switch is thrown closed at t = 0. (a) Find the frequency (in hertz) of the resulting oscillations. (b) At t = 1.00 ms, find the charge on the capacitor and (c) the current in the circuit.4. The rms output voltage of an ac generator is 200 V, and the operating frequency is 100 Hz. Write the equation giving the output voltage as a function of time.5. (a) What is the resistance of a lightbulb that uses an average power of 75.0 W when connected to a 60.0-Hz power source having a maximum voltage of 170 V? (b) What is the resistance of a 100-W bulb?