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Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 861 · 40 questions
TalentJR

Remember (Find the topic, use the formula): Find the topic and the formula: V = I × R, I = V ÷ R, R = V ÷ I, P = V × I, units = W × h ÷ 1000. Change mA to A and kΩ to Ω before using a formula. Check: put your answer back into the formula.

NameDateTime takenScore ___ / 40
  1. 1.True or false: to unplug idle chargers saves electricity. (a) False (b) True
  2. 2.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  3. 3.True or false: the ammeter measures current. (a) False (b) True
  4. 4.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  5. 5.🔺 A current of 2.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  6. 6.🔺 A 0.6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  7. 7.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  8. 8.🧮 Resistors of 470 Ω, 50 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
  9. 9.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
  10. 10.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  11. 11.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a diode (c) a resistor (d) a capacitor
  12. 12.🔺 A 6.6 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
  13. 13.🌈 A resistor has the colour bands brown, red, brown. What is its value (in ohms)?
  14. 14.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.🔺 A current of 1.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
  16. 16.🧮 Resistors of 47 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
  17. 17.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
  18. 18.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) an oil lamp (c) a filament bulb (d) a candle
  19. 19.🔺 A current of 1.5 A flows when 4.5 V is joined across a resistor. What is its resistance (in ohms)?
  20. 20.🔺 A current of 10 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
  21. 21.True or false: to use old filament bulbs saves electricity. (a) False (b) True
  22. 22.🔺 A current of 0.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
  23. 23.🔺 A 6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  24. 24.🔺 A 4 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
  25. 25.Which of these is measured in ohms (Ω)? (a) resistance (b) the push of a cell (c) voltage (d) current
  26. 26.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  27. 27.🔺 A 1.5 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  28. 28.⚡ A device works on 24 V and takes 0.1 A. What is its power (in watts)? =
  29. 29.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
  30. 30.Which of these is measured in watts (W)? (a) how much a part resists (b) energy used each second (c) voltage (d) resistance
  31. 31.🔺 A current of 40 mA flows when 4.8 V is joined across a resistor. What is its resistance (in ohms)?
  32. 32.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 93000 Ω resistor? (a) orange-white-orange (b) white-orange-orange (c) white-orange-red (d) white-orange-yellow
  33. 33.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
  34. 34.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = I ÷ V (d) P = V × I
  35. 35.Which of these is measured in ohms (Ω)? (a) how much a part resists (b) energy used each second (c) the push of a cell (d) current
  36. 36.🔺 A current of 1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
  37. 37.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  38. 38.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  39. 39.True or false: power is measured in volts (V). (a) True (b) False
  40. 40.📏 How many ohms (Ω) is 0.1 kΩ?

Answer key

  1. True
  2. saves electricity
  3. True
  4. 50
  5. 3
  6. 0.1
  7. anode (+)
  8. 530
  9. False
  10. 40
  11. a buzzer
  12. 20
  13. 120
  14. 3.3
  15. 30
  16. 115
  17. voltmeter
  18. an LED lamp
  19. 3
  20. 4
  21. False
  22. 6
  23. 1
  24. 10
  25. resistance
  26. 3.75
  27. 0.25
  28. 2.4
  29. 80
  30. energy used each second
  31. 120
  32. white-orange-orange
  33. 230
  34. P = V × I
  35. how much a part resists
  36. 10
  37. cathode (−)
  38. anode (+)
  39. False
  40. 100

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