← 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 991 · 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 current of 0.2 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  2. 2.True or false: on an LED, the round-side leg is the anode (+). (a) True (b) False
  3. 3.🧮 Five equal 250 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 78000 Ω resistor? (a) violet-grey-red (b) grey-violet-orange (c) violet-grey-orange (d) violet-grey-yellow
  5. 5.🌈 In the resistor colour code, which number does brown stand for?
  6. 6.🔺 A current of 0.2 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  7. 7.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V ÷ I (d) R = V + I
  8. 8.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
  9. 9.🔺 A 40 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  10. 10.🔺 A 10 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  11. 11.🔺 A current of 3 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
  12. 12.🌈 In the resistor colour code, which number does blue stand for?
  13. 13.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
  14. 14.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.True or false: to use LED lamps wastes electricity. (a) True (b) False
  16. 16.💡 An LED is joined to a 3 V battery through a 330 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) does not light (c) may burn out
  17. 17.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
  18. 18.📏 How many milliamperes (mA) make 1 ampere? (a) 60 (b) 100 (c) 10 (d) 1000
  19. 19.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  20. 20.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 29 Ω resistor? (a) orange-white-black (b) red-white-brown (c) white-red-black (d) red-white-black
  21. 21.True or false: the voltmeter is joined in series. (a) False (b) True
  22. 22.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V + I (d) P = V × I
  23. 23.🌈 A resistor has the colour bands yellow, white, brown. What is its value (in ohms)?
  24. 24.🧩 Which component boosts a small signal? (a) diode (b) transistor (c) buzzer (d) LDR
  25. 25.🔺 A current of 40 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
  26. 26.🧩 Which component makes a beeping sound? (a) potentiometer (b) transistor (c) buzzer (d) resistor
  27. 27.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 71000 Ω resistor? (a) violet-brown-yellow (b) brown-violet-orange (c) violet-brown-red (d) violet-brown-orange
  28. 28.True or false: a thermistor makes things spin. (a) False (b) True
  29. 29.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
  30. 30.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
  31. 31.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  32. 32.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) more than either one (d) less than either one
  33. 33.🌈 In the resistor colour code, which number does yellow stand for?
  34. 34.📏 In the water-pipe picture of a circuit, current is like … (a) a narrow pipe (b) the pipe colour (c) the water pressure (d) the flow of water
  35. 35.🧮 Four equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  36. 36.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  37. 37.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  38. 38.💡 Why does an LED need a resistor in series? (a) to store charge (b) to limit the current (c) to make it brighter (d) to change its colour
  39. 39.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  40. 40.🔺 A current of 10 mA flows when 3.3 V is joined across a resistor. What is its resistance (in ohms)?

Answer key

  1. 1.2
  2. True
  3. 50
  4. violet-grey-orange
  5. 1
  6. 3
  7. R = V ÷ I
  8. 1840
  9. 2
  10. 1
  11. 2
  12. 6
  13. 3.3
  14. 1.2
  15. False
  16. lights up
  17. 8.8
  18. 1000
  19. cathode (−)
  20. red-white-black
  21. False
  22. P = V × I
  23. 490
  24. transistor
  25. 18.8
  26. buzzer
  27. violet-brown-orange
  28. False
  29. 1150
  30. False
  31. 500
  32. less than either one
  33. 4
  34. the flow of water
  35. 50
  36. anode (+)
  37. saves electricity
  38. to limit the current
  39. 500
  40. 330

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