← 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 565 · 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.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
  2. 2.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  3. 3.📏 Which unit measures power? (a) ohm (Ω) (b) volt (V) (c) watt (W) (d) ampere (A)
  4. 4.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the length of a wire (d) the colour of light
  5. 5.🧮 A 330 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  6. 6.🔺 A 2 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  7. 7.🔺 A current of 40 mA flows when 16 V is joined across a resistor. What is its resistance (in ohms)?
  8. 8.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
  9. 9.🧩 Which component beeps for an alarm? (a) transistor (b) LDR (c) resistor (d) buzzer
  10. 10.Which of these saves electricity? (a) set the AC to 24 °C (b) leave the TV on standby (c) iron one shirt at a time (d) use old filament bulbs
  11. 11.🔺 A current of 2 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  12. 12.🧮 Three equal 15 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  13. 13.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) zero (d) stay the same
  14. 14.🔺 A current of 50 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
  16. 16.🌈 In the resistor colour code, which number does violet stand for?
  17. 17.🔺 A current of 2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  18. 18.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = V × I (c) R = V ÷ I (d) R = I ÷ V
  19. 19.🔺 A current of 0.2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  20. 20.🧩 Which component has coloured bands? (a) LED (b) thermistor (c) resistor (d) transistor
  21. 21.⚡ A 0.9 W device works on 9 V. What current does it take (in amperes)? =
  22. 22.📏 How many amperes (A) is 2890 mA? =
  23. 23.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to change its colour (c) to store charge (d) to limit the current
  24. 24.True or false: the flow of charge is measured in volts (V). (a) True (b) False
  25. 25.🔺 A current of 10 mA flows when 3.3 V is joined across a resistor. What is its resistance (in ohms)?
  26. 26.🔺 A 10 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  27. 27.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
  28. 28.🔺 A current of 1 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
  29. 29.📏 How many kilo-ohms (kΩ) is 6500 Ω? =
  30. 30.🔺 A current of 2.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  31. 31.🔺 A current of 0.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  32. 32.🔺 A 4 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
  33. 33.🔺 A 4 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  34. 34.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
  35. 35.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = R ÷ V (c) I = V × R (d) I = V ÷ R
  36. 36.🌈 A resistor has the colour bands brown, green, red. What is its value (in ohms)?
  37. 37.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  38. 38.Which of these is measured in ohms (Ω)? (a) voltage (b) the flow of charge (c) resistance (d) power
  39. 39.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
  40. 40.True or false: an LED lets current go one way. (a) True (b) False

Answer key

  1. 3
  2. wastes electricity
  3. watt (W)
  4. energy used each second
  5. 340
  6. 20
  7. 400
  8. 1 kilowatt-hour (kWh)
  9. buzzer
  10. set the AC to 24 °C
  11. 12
  12. 5
  13. bigger
  14. 10
  15. P = V × I
  16. 7
  17. 8
  18. R = V ÷ I
  19. 0.4
  20. resistor
  21. 0.1
  22. 2.89
  23. to limit the current
  24. False
  25. 330
  26. 40
  27. voltmeter
  28. 5
  29. 6.5
  30. 10
  31. 7.5
  32. 10
  33. 0.5
  34. 6
  35. I = V ÷ R
  36. 1500
  37. 50
  38. resistance
  39. voltmeter
  40. False

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