← Part 2 test: components and Ohm’s law lesson New set →

Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 85 · 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.Which of these wastes electricity? (a) unplug idle chargers (b) set the AC to 24 °C (c) run fans in empty rooms (d) use LED lamps
  2. 2.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it makes a sound (c) it changes colour (d) it does not light
  3. 3.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V ÷ R (c) I = V + R (d) I = V × R
  4. 4.📏 How many amperes (A) is 2330 mA? =
  5. 5.🌈 A resistor has the colour bands green, blue, red. What is its value (in ohms)?
  6. 6.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  7. 7.🧮 Resistors of 33 Ω and 330 Ω are joined in series. What is the total resistance (in ohms)?
  8. 8.🧮 Resistors of 10 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
  9. 9.📏 How many ohms (Ω) is 3 kΩ?
  10. 10.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  11. 11.🌈 A resistor has the colour bands orange, violet, orange. What is its value in kilo-ohms (kΩ)? =
  12. 12.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) bigger (d) stay the same
  13. 13.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  14. 14.🧮 A 10 V battery is joined to 12 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
  15. 15.🔺 A current of 10 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
  16. 16.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water tank lid (b) the water pressure (c) the tap handle (d) the pipe colour
  17. 17.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
  18. 18.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
  19. 19.🔺 A current of 10 mA flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
  20. 20.🔺 A current of 2 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  21. 21.🔺 A current of 0.25 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  22. 22.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  23. 23.🌈 A resistor has the colour bands green, blue, brown. What is its value (in ohms)?
  24. 24.🔺 A current of 0.1 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  25. 25.💡 An LED is joined to a 3 V battery through a 1000 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
  26. 26.💡 An LED is joined to a 6 V battery through a 1000 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) lights up (c) may burn out
  27. 27.🔺 A current of 1.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
  28. 28.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
  29. 29.🧮 A 150 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  30. 30.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
  31. 31.🌈 A resistor has the colour bands white, blue, brown. What is its value (in ohms)?
  32. 32.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V × I (c) P = V ÷ I (d) P = V + I
  33. 33.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  34. 34.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  35. 35.📏 Which unit measures current? (a) volt (V) (b) ohm (Ω) (c) watt (W) (d) ampere (A)
  36. 36.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 watt
  37. 37.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = I × R (d) V = R ÷ I
  38. 38.🔺 A 2 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  39. 39.🔺 A current of 0.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  40. 40.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?

Answer key

  1. run fans in empty rooms
  2. it does not light
  3. I = V ÷ R
  4. 2.33
  5. 5600
  6. cathode (−)
  7. 363
  8. 30
  9. 3000
  10. wastes electricity
  11. 37
  12. bigger
  13. 85
  14. 0.5
  15. 2
  16. the water pressure
  17. 6
  18. 920
  19. 120
  20. 5
  21. 3.75
  22. saves electricity
  23. 560
  24. 0.6
  25. lights up
  26. lights up
  27. 7.5
  28. 115
  29. 315
  30. 230
  31. 960
  32. P = V × I
  33. 102
  34. 408
  35. ampere (A)
  36. 1 kilowatt-hour (kWh)
  37. V = I × R
  38. 0.25
  39. 15
  40. 460

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids