← 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 882 · 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.🔺 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
  2. 2.🔍 Which is the odd one out? (a) leave fridge door open (b) use LED lamps (c) leave the TV on standby (d) iron one shirt at a time
  3. 3.🧮 Resistors of 100 Ω, 100 Ω, 22 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
  4. 4.What does a resistor do? (a) limits the current (b) glows using little power (c) makes a beeping sound (d) turns a fan or wheels
  5. 5.🌈 A resistor has the colour bands grey, white, orange. What is its value (in ohms)?
  6. 6.🔺 A current of 3 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
  7. 7.⚡ A device works on 5 V and takes 3 A. What is its power (in watts)? =
  8. 8.🌈 In the resistor colour code, which number does white stand for?
  9. 9.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  10. 10.🔍 Which is the odd one out? (a) run fans in empty rooms (b) use daylight to read (c) leave the TV on standby (d) leave fridge door open
  11. 11.🧩 Which component senses how bright it is? (a) motor (b) thermistor (c) transistor (d) LDR
  12. 12.🌈 In the resistor colour code, which number does red stand for?
  13. 13.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  14. 14.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
  15. 15.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to change its colour (d) to limit the current
  16. 16.True or false: the ammeter measures voltage. (a) True (b) False
  17. 17.🔺 A 1.2 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  18. 18.🔺 A 4 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  19. 19.🌈 A resistor has the colour bands violet, grey, orange. What is its value in kilo-ohms (kΩ)? =
  20. 20.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) stay the same (c) bigger (d) zero
  21. 21.🔺 A current of 10 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  22. 22.🔺 A current of 50 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
  23. 23.🧮 Resistors of 47 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
  24. 24.🧾 A family uses 70 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  25. 25.True or false: voltage is measured in volts (V). (a) True (b) False
  26. 26.Which of these is measured in ohms (Ω)? (a) the flow of charge (b) current (c) energy used each second (d) resistance
  27. 27.📏 How many kilowatts (kW) is 3150 W? =
  28. 28.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  29. 29.📏 Which unit measures how much a part resists? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
  30. 30.🌈 A resistor has the colour bands red, green, orange. What is its value in kilo-ohms (kΩ)? =
  31. 31.📏 How many milliamperes (mA) is 1.13 A?
  32. 32.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 89000 Ω resistor? (a) grey-white-red (b) white-grey-orange (c) grey-white-orange (d) grey-white-yellow
  33. 33.📏 How many watts (W) is 1.8 kW?
  34. 34.🔺 A 0.6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  35. 35.🔺 A 1.2 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  36. 36.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  37. 37.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) a resistor (d) an LED
  38. 38.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
  39. 39.📏 Voltmeter or ammeter: which one measures current? (a) voltmeter (b) ammeter
  40. 40.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?

Answer key

  1. V = I × R
  2. use LED lamps
  3. 232
  4. limits the current
  5. 89000
  6. 60
  7. 15
  8. 9
  9. anode (+)
  10. use daylight to read
  11. LDR
  12. 2
  13. 165
  14. 1 kilowatt-hour (kWh)
  15. to limit the current
  16. False
  17. 10
  18. 20
  19. 78
  20. bigger
  21. 500
  22. 23.5
  23. 57
  24. 280
  25. True
  26. resistance
  27. 3.15
  28. 500
  29. ohm (Ω)
  30. 25
  31. 1130
  32. grey-white-orange
  33. 1800
  34. 0.2
  35. 0.2
  36. 5
  37. a motor
  38. 1840
  39. ammeter
  40. 240

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