← 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 480 · 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 0.7 V battery is joined to 4 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
  2. 2.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V × R (c) I = R ÷ V (d) I = V + R
  3. 3.🧮 Resistors of 50 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
  4. 4.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
  5. 5.⚡ Power tells us … (a) energy used each second (b) the size of a cell (c) the colour of light (d) the length of a wire
  6. 6.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a capacitor (d) a buzzer
  7. 7.🔺 A current of 0.1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  8. 8.🔺 A current of 20 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
  9. 9.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = R ÷ I (c) V = I + R (d) V = I × R
  10. 10.🧩 Which component lets current go one way? (a) diode (b) transistor (c) resistor (d) fuse
  11. 11.🔺 A current of 25 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
  12. 12.🔺 A current of 40 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  13. 13.📏 How many milliamperes (mA) is 2.59 A?
  14. 14.🔺 A current of 40 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.🔺 A current of 0.2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  16. 16.Which of these is measured in watts (W)? (a) power (b) the flow of charge (c) current (d) the push of a cell
  17. 17.🔺 A current of 1 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  18. 18.🔺 A current of 0.1 A flows when 0.2 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  20. 20.🔺 A current of 0.2 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
  21. 21.🔺 A 25 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  22. 22.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 10 (b) 1000 (c) 100 (d) 1024
  23. 23.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V + I (c) P = V ÷ I (d) P = V × I
  24. 24.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  25. 25.🧮 Two equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  26. 26.🔺 A current of 50 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
  27. 27.📏 How many kilowatts (kW) is 2300 W? =
  28. 28.🔺 A current of 20 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  29. 29.🧮 A 5 V battery is joined to 4 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
  30. 30.Which of these wastes electricity? (a) unplug idle chargers (b) switch off empty rooms (c) leave the TV on standby (d) use LED lamps
  31. 31.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets bigger (c) gets smaller (d) stays the same
  32. 32.🌈 Which band is read first on a resistor? (a) the widest gap (b) any band (c) the one nearest an end (d) the gold band
  33. 33.🧩 Which component makes a beeping sound? (a) buzzer (b) motor (c) transistor (d) resistor
  34. 34.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  35. 35.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
  36. 36.🌈 A resistor has the colour bands brown, blue, red. What is its value (in ohms)?
  37. 37.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) use LED lamps (d) iron one shirt at a time
  38. 38.🔺 A 1.5 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  39. 39.🔺 A current of 0.2 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
  40. 40.🧩 A capacitor in a circuit can … (a) make light (b) store charge briefly (c) measure heat (d) spin a wheel

Answer key

  1. 0.1
  2. I = V ÷ R
  3. 83
  4. 1
  5. energy used each second
  6. a buzzer
  7. 0.4
  8. 4.4
  9. V = I × R
  10. diode
  11. 2.5
  12. 20
  13. 2590
  14. 13.2
  15. 0.8
  16. power
  17. 10
  18. 2
  19. 126
  20. 4
  21. 50
  22. 1000
  23. P = V × I
  24. 189
  25. 100
  26. 12.5
  27. 2.3
  28. 10
  29. 0.5
  30. leave the TV on standby
  31. gets smaller
  32. the one nearest an end
  33. buzzer
  34. cathode (−)
  35. 115
  36. 1600
  37. use LED lamps
  38. 10
  39. 1.6
  40. store charge briefly

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