← 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 147 · 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.What does a resistor do? (a) stores a little charge (b) beeps for an alarm (c) makes a beeping sound (d) limits the current
  2. 2.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) smaller (d) zero
  3. 3.🧩 Which component limits the current? (a) potentiometer (b) motor (c) fuse (d) resistor
  4. 4.🧮 A 4 V battery is joined to 8 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
  5. 5.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 ampere (d) 1 volt
  6. 6.📏 Which unit measures the push of a cell? (a) watt (W) (b) volt (V) (c) ohm (Ω) (d) ampere (A)
  7. 7.⚡ A 0.6 W device works on 6 V. What current does it take (in amperes)? =
  8. 8.🧩 Which component has coloured bands? (a) transistor (b) resistor (c) fuse (d) thermistor
  9. 9.💡 An LED is joined to a 3 V battery through a 220 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) does not light (b) lights up (c) may burn out
  10. 10.True or false: a diode beeps for an alarm. (a) True (b) False
  11. 11.🔺 A 45 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  12. 12.🔺 A current of 10 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
  13. 13.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 5 V supply. What current flows (in mA)?
  14. 14.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a buzzer (d) a resistor
  15. 15.🧮 Three equal 150 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  16. 16.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
  17. 17.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water tank lid (b) the water pressure (c) the tap handle (d) the pipe colour
  18. 18.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) gets bigger (d) becomes zero
  19. 19.📏 How many watts (W) is 0.3 kW?
  20. 20.What does a capacitor do? (a) makes things spin (b) has coloured bands (c) beeps for an alarm (d) stores a little charge
  21. 21.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I ÷ R (c) V = I × R (d) V = I + R
  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 device works on 3 V and takes 2 A. What is its power (in watts)? =
  24. 24.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 25 % (c) 5 % (d) 50 %
  25. 25.💡 What does LED stand for? (a) low energy device (b) light energy dial (c) light-emitting diode (d) large electric dial
  26. 26.🧮 A 20 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  27. 27.💡 An LED is joined to a 5 V battery through a 220 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) may burn out (b) lights up (c) does not light
  28. 28.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 71 Ω resistor? (a) violet-brown-black (b) grey-brown-black (c) brown-violet-black (d) violet-brown-brown
  29. 29.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
  30. 30.⚡ A 6 W device works on 6 V. What current does it take (in amperes)? =
  31. 31.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  32. 32.Which of these is measured in watts (W)? (a) resistance (b) the flow of charge (c) energy used each second (d) voltage
  33. 33.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  34. 34.⚡ A 27 W device works on 9 V. What current does it take (in amperes)? =
  35. 35.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
  36. 36.Which of these saves electricity? (a) leave the TV on standby (b) set the AC to 24 °C (c) use old filament bulbs (d) iron one shirt at a time
  37. 37.🔺 A current of 0.25 A flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  38. 38.🌈 A resistor has the colour bands brown, blue, yellow. What is its value in kilo-ohms (kΩ)? =
  39. 39.📏 How many amperes (A) is 1870 mA? =
  40. 40.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =

Answer key

  1. limits the current
  2. bigger
  3. resistor
  4. 0.25
  5. 1 kilowatt-hour (kWh)
  6. volt (V)
  7. 0.1
  8. resistor
  9. lights up
  10. False
  11. 3
  12. 4
  13. 15
  14. a buzzer
  15. 50
  16. 0.1
  17. the water pressure
  18. gets smaller
  19. 300
  20. stores a little charge
  21. V = I × R
  22. P = V × I
  23. 6
  24. 5 %
  25. light-emitting diode
  26. 185
  27. does not light
  28. violet-brown-black
  29. voltmeter
  30. 1
  31. saves electricity
  32. energy used each second
  33. 25
  34. 3
  35. 1
  36. set the AC to 24 °C
  37. 10
  38. 160
  39. 1.87
  40. 1

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