← 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 884 · 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.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) becomes zero (d) gets bigger
  2. 2.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
  3. 3.🌈 A resistor has the colour bands red, black, orange. What is its value in kilo-ohms (kΩ)? =
  4. 4.🧮 Five equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  5. 5.⚡ A device works on 6 V and takes 3 A. What is its power (in watts)? =
  6. 6.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) a candle (c) an oil lamp (d) an LED lamp
  7. 7.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) set the AC to 24 °C (d) leave fridge door open
  8. 8.🌈 A resistor has the colour bands yellow, red, black. What is its value (in ohms)?
  9. 9.📏 How many kilowatts (kW) is 3600 W? =
  10. 10.🧮 Resistors of 33 Ω, 47 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
  11. 11.Which of these wastes electricity? (a) unplug idle chargers (b) set the AC to 24 °C (c) use daylight to read (d) leave the TV on standby
  12. 12.🧩 Which component makes things spin? (a) LED (b) resistor (c) motor (d) LDR
  13. 13.📏 How many amperes (A) is 590 mA? =
  14. 14.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  15. 15.📏 How many milliamperes (mA) make 1 ampere? (a) 60 (b) 1000 (c) 100 (d) 10
  16. 16.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?
  17. 17.True or false: a diode lets current go one way. (a) True (b) False
  18. 18.🧩 Which component lets current go one way? (a) diode (b) transistor (c) buzzer (d) LDR
  19. 19.🌈 A resistor has the colour bands orange, black, brown. What is its value (in ohms)?
  20. 20.🧮 A 2.8 V battery is joined to 2 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
  21. 21.📏 How many kilo-ohms (kΩ) is 6300 Ω? =
  22. 22.🔺 A current of 0.2 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
  23. 23.What does a capacitor do? (a) smooths a wobbly supply (b) blows if current is high (c) glows using little power (d) boosts a small signal
  24. 24.🧮 Resistors of 470 Ω, 47 Ω, 22 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
  25. 25.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 2.5 V supply. What current flows (in mA)?
  26. 26.🌈 Which band is read first on a resistor? (a) the widest gap (b) the gold band (c) the one nearest an end (d) any band
  27. 27.Which of these wastes electricity? (a) leave fridge door open (b) unplug idle chargers (c) set the AC to 24 °C (d) use LED lamps
  28. 28.🔺 A current of 0.2 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
  29. 29.🧩 Which component makes a beeping sound? (a) transistor (b) buzzer (c) diode (d) LED
  30. 30.True or false: the ammeter is joined in series. (a) False (b) True
  31. 31.True or false: a buzzer makes a beeping sound. (a) False (b) True
  32. 32.📏 Which unit measures power? (a) ohm (Ω) (b) ampere (A) (c) volt (V) (d) watt (W)
  33. 33.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a resistor (d) a diode
  34. 34.⚡ A device works on 24 V and takes 3 A. What is its power (in watts)? =
  35. 35.🧩 Which component turns a fan or wheels? (a) LDR (b) resistor (c) motor (d) LED
  36. 36.🔺 A current of 50 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = V × R (d) I = R ÷ V
  38. 38.🧮 Resistors of 22 Ω and 33 Ω are joined in series. What is the total resistance (in ohms)?
  39. 39.🧩 Which component smooths a wobbly supply? (a) transistor (b) LDR (c) capacitor (d) LED
  40. 40.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = R ÷ I (d) V = I × R

Answer key

  1. gets smaller
  2. 460
  3. 20
  4. 20
  5. 18
  6. an LED lamp
  7. set the AC to 24 °C
  8. 42
  9. 3.6
  10. 148
  11. leave the TV on standby
  12. motor
  13. 0.59
  14. cathode (−)
  15. 1000
  16. 5
  17. True
  18. diode
  19. 300
  20. 0.2
  21. 6.3
  22. 2
  23. smooths a wobbly supply
  24. 559
  25. 5
  26. the one nearest an end
  27. leave fridge door open
  28. 15
  29. buzzer
  30. True
  31. True
  32. watt (W)
  33. a buzzer
  34. 72
  35. motor
  36. 150
  37. I = V ÷ R
  38. 55
  39. capacitor
  40. V = I × R

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