← 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 611 · 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 2.5 V battery is joined to 6 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
  2. 2.📏 How many watts (W) is 2.1 kW?
  3. 3.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
  4. 4.🔺 A 10 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  5. 5.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 50 % (c) 0 % (d) 5 %
  6. 6.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
  7. 7.🔺 A current of 0.25 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  8. 8.True or false: a thermistor senses how hot it is. (a) False (b) True
  9. 9.🔺 A current of 0.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
  10. 10.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
  11. 11.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = V × I (d) R = I ÷ V
  12. 12.🔺 A current of 20 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
  13. 13.What does a fuse do? (a) makes things spin (b) makes a beeping sound (c) has coloured bands (d) blows if current is high
  14. 14.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  15. 15.🔺 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
  16. 16.🔺 A 2.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  17. 17.True or false: to use LED lamps wastes electricity. (a) True (b) False
  18. 18.🌈 A resistor has the colour bands grey, grey, black. What is its value (in ohms)?
  19. 19.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) energy used each second (d) the size of a cell
  20. 20.🧮 A 470 Ω resistor is joined in series with two equal 50 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  21. 21.💡 Why does an LED need a resistor in series? (a) to store charge (b) to limit the current (c) to change its colour (d) to make it brighter
  22. 22.💡 An LED is joined to a 6 V battery through a 330 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) does not light (c) lights up
  23. 23.🔺 A current of 0.25 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  24. 24.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
  25. 25.🔺 A current of 1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
  26. 26.🧩 Which part changes electrical energy into movement? (a) an LED (b) a resistor (c) a fuse (d) a motor
  27. 27.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = I ÷ V (c) P = V + I (d) P = V × I
  28. 28.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  29. 29.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) an oil lamp (d) a candle
  30. 30.🔺 A current of 2 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  31. 31.🧮 A 0.7 V battery is joined to 3 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
  32. 32.What does a diode do? (a) makes things spin (b) smooths a wobbly supply (c) lets current go one way (d) makes a beeping sound
  33. 33.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
  34. 34.🔺 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
  35. 35.True or false: the voltmeter is joined across a part. (a) True (b) False
  36. 36.🔺 A current of 10 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
  37. 37.🧮 A 10 Ω resistor is joined in series with two equal 470 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  38. 38.🧮 Two resistors in parallel give a total that is … (a) their sum (b) always zero (c) more than either one (d) less than either one
  39. 39.🔺 A current of 0.2 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  40. 40.📏 Which unit measures current? (a) watt (W) (b) ampere (A) (c) volt (V) (d) ohm (Ω)

Answer key

  1. 0.25
  2. 2100
  3. True
  4. 2
  5. 5 %
  6. 2.5
  7. 1
  8. True
  9. 4
  10. 1 kilowatt-hour (kWh)
  11. R = V ÷ I
  12. 8
  13. blows if current is high
  14. 1.5
  15. V = I × R
  16. 10
  17. False
  18. 88
  19. energy used each second
  20. 495
  21. to limit the current
  22. lights up
  23. 8
  24. 1
  25. 3
  26. a motor
  27. P = V × I
  28. saves electricity
  29. an LED lamp
  30. 10
  31. 0.1
  32. lets current go one way
  33. 2300
  34. I = V ÷ R
  35. True
  36. 2
  37. 245
  38. less than either one
  39. 3
  40. ampere (A)

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