← 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 171 · 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 part changes electrical energy into movement? (a) an LED (b) a motor (c) a fuse (d) a resistor
  2. 2.🔺 A 3 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  3. 3.🧩 Which component lets current go one way? (a) diode (b) capacitor (c) LDR (d) potentiometer
  4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 35 Ω resistor? (a) yellow-green-black (b) orange-green-brown (c) orange-green-black (d) green-orange-black
  5. 5.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) zero (c) stay the same (d) smaller
  6. 6.🔺 A current of 3 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  7. 7.🔺 A current of 0.25 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  8. 8.📏 Which unit measures the push of a cell? (a) ohm (Ω) (b) ampere (A) (c) volt (V) (d) watt (W)
  9. 9.True or false: a diode makes a beeping sound. (a) True (b) False
  10. 10.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it changes colour (c) it makes a sound (d) it does not light
  11. 11.🔺 A current of 25 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  12. 12.Which of these saves electricity? (a) iron one shirt at a time (b) switch off empty rooms (c) run fans in empty rooms (d) use old filament bulbs
  13. 13.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
  14. 14.🔺 A 1 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  15. 15.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 24000 Ω resistor? (a) yellow-red-orange (b) red-yellow-yellow (c) red-yellow-red (d) red-yellow-orange
  16. 16.True or false: how much a part resists is measured in ohms (Ω). (a) False (b) True
  17. 17.Which of these is measured in watts (W)? (a) energy used each second (b) current (c) how much a part resists (d) the flow of charge
  18. 18.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  19. 19.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 50 % (c) 0 % (d) 5 %
  20. 20.📏 How many kilo-ohms (kΩ) is 8200 Ω? =
  21. 21.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  22. 22.🧮 A 22 Ω resistor is joined in series with two equal 1000 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  23. 23.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2800 Ω resistor? (a) grey-red-red (b) red-grey-red (c) red-grey-orange (d) red-grey-brown
  24. 24.🌈 In the resistor colour code, which number does black stand for?
  25. 25.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
  26. 26.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
  27. 27.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
  28. 28.🌈 In the resistor colour code, which number does green stand for?
  29. 29.🌈 A resistor has the colour bands green, blue, orange. What is its value in kilo-ohms (kΩ)? =
  30. 30.🌈 A resistor has the colour bands orange, grey, black. What is its value (in ohms)?
  31. 31.🌈 A resistor has the colour bands grey, yellow, yellow. What is its value in kilo-ohms (kΩ)? =
  32. 32.What does a diode do? (a) smooths a wobbly supply (b) senses how hot it is (c) lets current go one way (d) makes things spin
  33. 33.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
  34. 34.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  35. 35.🧾 A family uses 180 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  36. 36.🧩 A capacitor in a circuit can … (a) make light (b) measure heat (c) spin a wheel (d) store charge briefly
  37. 37.True or false: a fuse has coloured bands. (a) True (b) False
  38. 38.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
  39. 39.🔺 A current of 25 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
  40. 40.🧮 A 17 V battery is joined to 5 Ω and 12 Ω resistors in series. What current flows (in amperes)? =

Answer key

  1. a motor
  2. 25
  3. diode
  4. orange-green-black
  5. bigger
  6. 6
  7. 0.5
  8. volt (V)
  9. False
  10. it does not light
  11. 3.75
  12. switch off empty rooms
  13. False
  14. 10
  15. red-yellow-orange
  16. True
  17. energy used each second
  18. saves electricity
  19. 5 %
  20. 8.2
  21. cathode (−)
  22. 522
  23. red-grey-red
  24. 0
  25. 6
  26. 5.5
  27. 15
  28. 5
  29. 56
  30. 38
  31. 840
  32. lets current go one way
  33. 230
  34. 0.2
  35. 720
  36. store charge briefly
  37. False
  38. 2
  39. 8.25
  40. 1

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