← 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 953 · 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 current of 1.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
  2. 2.True or false: the ammeter measures current. (a) False (b) True
  3. 3.🔺 A 10 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  4. 4.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 ampere
  5. 5.🔺 A current of 0.2 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
  6. 6.Which of these wastes electricity? (a) use LED lamps (b) leave the TV on standby (c) switch off empty rooms (d) close the fridge quickly
  7. 7.True or false: an LDR makes a beeping sound. (a) True (b) False
  8. 8.🧮 Three equal 300 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  9. 9.🧮 Resistors of 20 Ω, 50 Ω, 33 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
  10. 10.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
  11. 11.💡 A red LED uses 2 V and should get 10 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
  12. 12.🔺 A current of 0.1 A flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
  13. 13.Which of these is measured in volts (V)? (a) current (b) voltage (c) power (d) how much a part resists
  14. 14.🔺 A 15 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  15. 15.📏 In the water-pipe picture of a circuit, voltage is like … (a) the tap handle (b) the water pressure (c) the pipe colour (d) the water tank lid
  16. 16.🔺 A 1 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  17. 17.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  18. 18.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =
  19. 19.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) the widest gap (d) any band
  20. 20.⚡ A device works on 24 V and takes 0.25 A. What is its power (in watts)? =
  21. 21.🔍 Which is the odd one out? (a) leave fridge door open (b) close the fridge quickly (c) unplug idle chargers (d) use LED lamps
  22. 22.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  23. 23.🔺 A current of 0.1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  24. 24.⚡ A device works on 1.5 V and takes 0.25 A. What is its power (in watts)? =
  25. 25.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) bigger (c) stay the same (d) smaller
  26. 26.📏 How many milliamperes (mA) is 2.23 A?
  27. 27.🧩 Which part changes electrical energy into movement? (a) an LED (b) a resistor (c) a motor (d) a fuse
  28. 28.🔺 A current of 50 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  29. 29.What does a transistor do? (a) is a resistance knob (b) senses how hot it is (c) boosts a small signal (d) glows using little power
  30. 30.🔺 A current of 40 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
  31. 31.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  32. 32.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = I ÷ V (c) R = V ÷ I (d) R = V × I
  33. 33.True or false: an LED glows using little power. (a) False (b) True
  34. 34.True or false: a motor turns a fan or wheels. (a) False (b) True
  35. 35.🧮 Two resistors in parallel give a total that is … (a) always zero (b) more than either one (c) less than either one (d) their sum
  36. 36.💡 An LED is joined to a 5 V battery with no resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) lights up (c) may burn out
  37. 37.🧾 A family uses 160 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  38. 38.True or false: the ammeter is joined across a part. (a) True (b) False
  39. 39.True or false: current is measured in ohms (Ω). (a) True (b) False
  40. 40.⚡ A device works on 3 V and takes 0.5 A. What is its power (in watts)? =

Answer key

  1. 18
  2. True
  3. 40
  4. 1 kilowatt-hour (kWh)
  5. 2
  6. leave the TV on standby
  7. False
  8. 100
  9. 203
  10. 0.1
  11. 700
  12. 12
  13. voltage
  14. 1
  15. the water pressure
  16. 0.2
  17. 10
  18. 0.6
  19. the one nearest an end
  20. 6
  21. leave fridge door open
  22. 7.5
  23. 0.2
  24. 0.375
  25. bigger
  26. 2230
  27. a motor
  28. 200
  29. boosts a small signal
  30. 12
  31. cathode (−)
  32. R = V ÷ I
  33. True
  34. True
  35. less than either one
  36. may burn out
  37. 1120
  38. False
  39. False
  40. 1.5

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