← 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 709 · 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 12 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  2. 2.📏 Which unit measures current? (a) watt (W) (b) volt (V) (c) ampere (A) (d) ohm (Ω)
  3. 3.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) an oil lamp (d) a candle
  4. 4.True or false: a thermistor smooths a wobbly supply. (a) False (b) True
  5. 5.🔺 A current of 1.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
  6. 6.🧮 A 330 Ω resistor is joined in series with two equal 40 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  7. 7.🧾 A family uses 160 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  8. 8.📏 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
  9. 9.⚡ A 9 W device works on 9 V. What current does it take (in amperes)? =
  10. 10.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
  11. 11.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
  12. 12.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  13. 13.⚡ A 0.6 W device works on 3 V. What current does it take (in amperes)? =
  14. 14.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  15. 15.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  16. 16.🔺 A current of 2.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
  17. 17.🌈 In the resistor colour code, which number does green stand for?
  18. 18.📏 How many kilowatts (kW) is 1500 W? =
  19. 19.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) smaller (c) bigger (d) zero
  20. 20.📏 How many amperes (A) is 1660 mA? =
  21. 21.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V ÷ I (c) R = I ÷ V (d) R = V + I
  22. 22.🧮 A 7 V battery is joined to 5 Ω and 2 Ω resistors in series. What current flows (in amperes)? =
  23. 23.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
  24. 24.🔺 A 0.6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  25. 25.💡 A red LED uses 2 V and should get 25 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
  26. 26.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
  27. 27.🔺 A 5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  28. 28.⚡ A 1.2 W device works on 12 V. What current does it take (in amperes)? =
  29. 29.🔺 A current of 1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  30. 30.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) less than either one (d) always zero
  31. 31.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
  32. 32.🌈 In the resistor colour code, which number does blue stand for?
  33. 33.🌈 In the resistor colour code, which number does grey stand for?
  34. 34.🔺 A current of 20 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
  35. 35.🧮 Three equal 300 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  36. 36.True or false: the flow of charge is measured in volts (V). (a) False (b) True
  37. 37.🔺 A 1 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  38. 38.⚡ A 1.8 W device works on 9 V. What current does it take (in amperes)? =
  39. 39.True or false: a resistor has coloured bands. (a) True (b) False
  40. 40.📏 How many milliamperes (mA) is 2.21 A?

Answer key

  1. 3
  2. ampere (A)
  3. an LED lamp
  4. False
  5. 18
  6. 350
  7. 800
  8. the flow of water
  9. 1
  10. voltmeter
  11. True
  12. 100
  13. 0.2
  14. 1020
  15. cathode (−)
  16. 12.5
  17. 5
  18. 1.5
  19. bigger
  20. 1.66
  21. R = V ÷ I
  22. 1
  23. 5.5
  24. 0.2
  25. 400
  26. 10
  27. 20
  28. 0.1
  29. 4
  30. less than either one
  31. 345
  32. 6
  33. 8
  34. 5
  35. 100
  36. False
  37. 0.2
  38. 0.2
  39. True
  40. 2210

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