← 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 571 · 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.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  2. 2.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  3. 3.True or false: the ammeter is joined in series. (a) True (b) False
  4. 4.🧮 A 47 Ω resistor is joined in series with two equal 100 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  5. 5.Which of these is measured in watts (W)? (a) current (b) how much a part resists (c) power (d) resistance
  6. 6.🧩 A capacitor in a circuit can … (a) measure heat (b) store charge briefly (c) make light (d) spin a wheel
  7. 7.True or false: the ammeter is joined across a part. (a) True (b) False
  8. 8.📏 How many kilowatts (kW) is 3850 W? =
  9. 9.📏 How many ohms (Ω) is 9.1 kΩ?
  10. 10.🌈 In the resistor colour code, which number does orange stand for?
  11. 11.True or false: a thermistor senses how hot it is. (a) False (b) True
  12. 12.📏 Which unit measures voltage? (a) watt (W) (b) ampere (A) (c) ohm (Ω) (d) volt (V)
  13. 13.🔺 A current of 20 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
  14. 14.🔺 A current of 50 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets smaller (c) gets bigger (d) stays the same
  16. 16.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
  17. 17.📏 Which unit measures resistance? (a) ohm (Ω) (b) ampere (A) (c) watt (W) (d) volt (V)
  18. 18.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  19. 19.📏 In the water-pipe picture of a circuit, current is like … (a) the pipe colour (b) the water pressure (c) the flow of water (d) a narrow pipe
  20. 20.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  21. 21.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V ÷ I (c) R = V × I (d) R = V + I
  22. 22.Which of these is measured in ohms (Ω)? (a) power (b) energy used each second (c) voltage (d) how much a part resists
  23. 23.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = V + I (d) P = I ÷ V
  24. 24.🔺 A current of 0.1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  25. 25.🔺 A current of 0.5 A flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
  26. 26.🧮 Two equal 50 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  27. 27.🌈 A resistor has the colour bands red, red, orange. What is its value in kilo-ohms (kΩ)? =
  28. 28.⚡ A device works on 5 V and takes 2 A. What is its power (in watts)? =
  29. 29.📏 How many amperes (A) is 450 mA? =
  30. 30.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
  31. 31.⚡ A 9 W device works on 6 V. What current does it take (in amperes)? =
  32. 32.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
  33. 33.🧩 Which component senses how hot it is? (a) transistor (b) fuse (c) thermistor (d) buzzer
  34. 34.⚡ A 36 W device works on 24 V. What current does it take (in amperes)? =
  35. 35.📏 How many kilo-ohms (kΩ) is 9000 Ω? =
  36. 36.🔺 A current of 0.25 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
  37. 37.🧩 Which component senses how bright it is? (a) fuse (b) buzzer (c) LDR (d) motor
  38. 38.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 7600 Ω resistor? (a) violet-blue-red (b) violet-blue-orange (c) violet-blue-brown (d) blue-violet-red
  39. 39.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
  40. 40.🧮 Resistors of 33 Ω, 100 Ω, 33 Ω and 470 Ω are joined in series. What is the total resistance (in ohms)?

Answer key

  1. cathode (−)
  2. 20
  3. True
  4. 97
  5. power
  6. store charge briefly
  7. False
  8. 3.85
  9. 9100
  10. 3
  11. True
  12. volt (V)
  13. 5
  14. 5
  15. gets smaller
  16. 1150
  17. ohm (Ω)
  18. 136
  19. the flow of water
  20. 4
  21. R = V ÷ I
  22. how much a part resists
  23. P = V × I
  24. 1.5
  25. 3
  26. 25
  27. 22
  28. 10
  29. 0.45
  30. 460
  31. 1.5
  32. 3
  33. thermistor
  34. 1.5
  35. 9
  36. 2.5
  37. LDR
  38. violet-blue-red
  39. 2.5
  40. 636

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