← 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 470 · 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.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) smaller (d) zero
  2. 2.🌈 A resistor has the colour bands white, yellow, red. What is its value (in ohms)?
  3. 3.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
  4. 4.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
  5. 5.🔺 A current of 0.25 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
  6. 6.True or false: how much a part resists is measured in ohms (Ω). (a) True (b) False
  7. 7.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  8. 8.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  9. 9.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  10. 10.⚡ A device works on 6 V and takes 0.2 A. What is its power (in watts)? =
  11. 11.⚡ A device works on 6 V and takes 1.5 A. What is its power (in watts)? =
  12. 12.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 5 V supply. What current flows (in mA)?
  13. 13.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) an LED lamp (c) a candle (d) a filament bulb
  14. 14.🔺 A current of 0.1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.🧩 A capacitor in a circuit can … (a) store charge briefly (b) measure heat (c) make light (d) spin a wheel
  16. 16.🔺 A current of 50 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
  17. 17.🔺 A 6.25 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  18. 18.🧩 Which part changes electrical energy into movement? (a) an LED (b) a motor (c) a fuse (d) a resistor
  19. 19.⚡ A 0.75 W device works on 1.5 V. What current does it take (in amperes)? =
  20. 20.🔺 A current of 0.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
  21. 21.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 950 Ω resistor? (a) white-green-brown (b) green-white-brown (c) white-green-black (d) white-green-red
  22. 22.⚡ A 7.5 W device works on 5 V. What current does it take (in amperes)? =
  23. 23.True or false: an LDR senses how bright it is. (a) True (b) False
  24. 24.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  25. 25.🌈 A resistor has the colour bands grey, grey, orange. What is its value in kilo-ohms (kΩ)? =
  26. 26.🧮 A 2.25 V battery is joined to 3 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
  27. 27.Which of these is measured in amperes (A)? (a) the push of a cell (b) energy used each second (c) resistance (d) current
  28. 28.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  29. 29.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
  30. 30.🔺 A current of 1.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
  31. 31.📏 In the water-pipe picture of a circuit, current is like … (a) the water pressure (b) the pipe colour (c) the flow of water (d) a narrow pipe
  32. 32.🔺 A current of 1.5 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  33. 33.🔺 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
  34. 34.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
  35. 35.📏 How many ohms (Ω) is 5.9 kΩ?
  36. 36.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  37. 37.What does a fuse do? (a) has coloured bands (b) blows if current is high (c) lets current go one way (d) beeps for an alarm
  38. 38.📏 How many kilo-ohms (kΩ) is 6500 Ω? =
  39. 39.📏 How many kilo-ohms (kΩ) is 5700 Ω? =
  40. 40.Which of these is measured in volts (V)? (a) current (b) power (c) the push of a cell (d) resistance

Answer key

  1. bigger
  2. 9400
  3. 1 kilowatt-hour (kWh)
  4. 115
  5. 2
  6. True
  7. 0.1
  8. 235
  9. 357
  10. 1.2
  11. 9
  12. 10
  13. an LED lamp
  14. 0.4
  15. store charge briefly
  16. 23.5
  17. 25
  18. a motor
  19. 0.5
  20. 10
  21. white-green-brown
  22. 1.5
  23. True
  24. 500
  25. 88
  26. 0.25
  27. current
  28. 3
  29. 230
  30. 4.5
  31. the flow of water
  32. 9
  33. I = V ÷ R
  34. True
  35. 5900
  36. anode (+)
  37. blows if current is high
  38. 6.5
  39. 5.7
  40. the push of a cell

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