← 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 971 · 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.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a resistor (c) a buzzer (d) a diode
  2. 2.📏 How many watts (W) is 0.8 kW?
  3. 3.🧩 Which component has coloured bands? (a) thermistor (b) resistor (c) LDR (d) diode
  4. 4.🔺 A current of 40 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
  5. 5.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
  6. 6.🔺 A current of 0.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
  7. 7.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
  8. 8.🧩 Which part changes electrical energy into movement? (a) an LED (b) a resistor (c) a fuse (d) a motor
  9. 9.🔺 A current of 0.1 A flows when 0.6 V is joined across a resistor. What is its resistance (in ohms)?
  10. 10.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) gets smaller (d) stays the same
  11. 11.🧮 A 2 V battery is joined to 2 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
  12. 12.🔺 A 12.5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  13. 13.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  14. 14.🔺 A current of 25 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.🧩 A capacitor in a circuit can … (a) spin a wheel (b) store charge briefly (c) measure heat (d) make light
  16. 16.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 41000 Ω resistor? (a) yellow-brown-yellow (b) yellow-brown-red (c) brown-yellow-orange (d) yellow-brown-orange
  17. 17.🔺 A current of 25 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
  18. 18.🧮 A 2 V battery is joined to 3 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
  19. 19.⚡ Which formula gives electric power? (a) P = V × I (b) P = I ÷ V (c) P = V ÷ I (d) P = V + I
  20. 20.🔺 A current of 0.25 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  21. 21.📏 Which unit measures how much a part resists? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
  22. 22.🧮 Resistors of 47 Ω, 20 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
  23. 23.💡 A red LED uses 2 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
  24. 24.🧾 A family uses 70 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  25. 25.🧮 A 68 Ω resistor is joined in series with two equal 1000 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  26. 26.🧮 Three equal 150 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  27. 27.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
  28. 28.🔺 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
  29. 29.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  30. 30.Which of these is measured in volts (V)? (a) power (b) current (c) the push of a cell (d) the flow of charge
  31. 31.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
  32. 32.🌈 In the resistor colour code, which number does white stand for?
  33. 33.⚡ A 1.2 W device works on 6 V. What current does it take (in amperes)? =
  34. 34.⚡ Power tells us … (a) the size of a cell (b) the colour of light (c) energy used each second (d) the length of a wire
  35. 35.🧮 Two resistors in parallel give a total that is … (a) their sum (b) more than either one (c) always zero (d) less than either one
  36. 36.⚡ A 12 W device works on 6 V. What current does it take (in amperes)? =
  37. 37.🌈 In the resistor colour code, which number does yellow stand for?
  38. 38.📏 Voltmeter or ammeter: which one is joined across a part? (a) voltmeter (b) ammeter
  39. 39.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
  40. 40.🔺 A current of 0.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =

Answer key

  1. a buzzer
  2. 800
  3. resistor
  4. 13.2
  5. 115
  6. 6
  7. 345
  8. a motor
  9. 6
  10. gets smaller
  11. 0.25
  12. 25
  13. 500
  14. 2.5
  15. store charge briefly
  16. yellow-brown-orange
  17. 11.75
  18. 0.25
  19. P = V × I
  20. 1
  21. ohm (Ω)
  22. 89
  23. 300
  24. 280
  25. 568
  26. 50
  27. 8.8
  28. V = I × R
  29. 25
  30. the push of a cell
  31. True
  32. 9
  33. 0.2
  34. energy used each second
  35. less than either one
  36. 2
  37. 4
  38. voltmeter
  39. 6
  40. 2.5

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