← 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 645 · 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.True or false: the voltmeter measures current. (a) True (b) False
  2. 2.🔺 A 25 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  3. 3.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = I ÷ V (d) P = V + I
  4. 4.🔺 A current of 0.1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
  5. 5.💡 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?
  6. 6.💡 An LED is joined to a 5 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) lights up (c) may burn out
  7. 7.🔺 A 3 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  8. 8.True or false: a diode has coloured bands. (a) False (b) True
  9. 9.True or false: on an LED, the longer leg is the anode (+). (a) False (b) True
  10. 10.True or false: the voltmeter is joined across a part. (a) False (b) True
  11. 11.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
  12. 12.🧮 Three equal 300 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) bigger (b) zero (c) smaller (d) stay the same
  14. 14.🌈 In the resistor colour code, which number does yellow stand for?
  15. 15.True or false: how much a part resists is measured in watts (W). (a) False (b) True
  16. 16.🌈 In the resistor colour code, which number does brown stand for?
  17. 17.🌈 In the resistor colour code, which number does green stand for?
  18. 18.True or false: a buzzer has coloured bands. (a) True (b) False
  19. 19.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) more than either one (c) always zero (d) their sum
  20. 20.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  21. 21.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  22. 22.🧩 Which component glows using little power? (a) LDR (b) potentiometer (c) LED (d) transistor
  23. 23.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  24. 24.🔺 A 0.5 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  25. 25.🌈 A resistor has the colour bands green, yellow, red. What is its value (in ohms)?
  26. 26.🔺 A current of 0.5 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
  27. 27.🧩 Which component limits the current? (a) LED (b) capacitor (c) potentiometer (d) resistor
  28. 28.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  29. 29.🔺 A current of 3 A flows when 60 V is joined across a resistor. What is its resistance (in ohms)?
  30. 30.Which of these is measured in amperes (A)? (a) how much a part resists (b) the push of a cell (c) current (d) resistance
  31. 31.🔺 A current of 2.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
  32. 32.🧾 A family uses 100 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  33. 33.🔺 A current of 10 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  34. 34.🔺 A current of 10 mA flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🧾 A family uses 170 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  36. 36.True or false: the push of a cell is measured in ohms (Ω). (a) True (b) False
  37. 37.🧩 Which component blows if current is high? (a) buzzer (b) thermistor (c) LED (d) fuse
  38. 38.🔺 A current of 1.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
  39. 39.📏 In the water-pipe picture of a circuit, resistance is like … (a) the water pressure (b) the flow of water (c) a bigger tank (d) a narrow pipe
  40. 40.🔺 A current of 10 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?

Answer key

  1. False
  2. 2.5
  3. P = V × I
  4. 0.3
  5. 400
  6. may burn out
  7. 0.5
  8. False
  9. True
  10. True
  11. voltmeter
  12. 100
  13. bigger
  14. 4
  15. False
  16. 1
  17. 5
  18. False
  19. less than either one
  20. 500
  21. 5
  22. LED
  23. anode (+)
  24. 0.25
  25. 5400
  26. 6
  27. resistor
  28. saves electricity
  29. 20
  30. current
  31. 12.5
  32. 400
  33. 1.5
  34. 100
  35. 1530
  36. False
  37. fuse
  38. 30
  39. a narrow pipe
  40. 300

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