← 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 145 · 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 colour bands (1st digit, 2nd digit, multiplier) mark an 840 Ω resistor? (a) grey-yellow-brown (b) grey-yellow-black (c) yellow-grey-brown (d) grey-yellow-red
  2. 2.🔺 A current of 25 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  3. 3.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 4 V supply. What current flows (in mA)?
  4. 4.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  5. 5.🧩 Which component makes a beeping sound? (a) resistor (b) motor (c) buzzer (d) LDR
  6. 6.🔺 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
  7. 7.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
  8. 8.Which of these is measured in amperes (A)? (a) the flow of charge (b) voltage (c) the push of a cell (d) how much a part resists
  9. 9.🔺 A 2.5 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  10. 10.🌈 A resistor has the colour bands red, red, black. What is its value (in ohms)?
  11. 11.⚡ A 0.5 W device works on 5 V. What current does it take (in amperes)? =
  12. 12.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a buzzer (d) a resistor
  13. 13.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  14. 14.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  15. 15.⚡ Power tells us … (a) the length of a wire (b) energy used each second (c) the size of a cell (d) the colour of light
  16. 16.🧮 Five equal 250 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  17. 17.🧩 A capacitor in a circuit can … (a) measure heat (b) spin a wheel (c) store charge briefly (d) make light
  18. 18.🧾 A family uses 180 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  19. 19.🧾 A family uses 30 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  20. 20.💡 An LED is joined to a 6 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) may burn out (c) lights up
  21. 21.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
  22. 22.🌈 In the resistor colour code, which number does black stand for?
  23. 23.🧮 A 2.4 V battery is joined to 12 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
  24. 24.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
  25. 25.📏 How many kilo-ohms (kΩ) is 9600 Ω? =
  26. 26.🔺 A current of 50 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  27. 27.⚡ A 6 W device works on 12 V. What current does it take (in amperes)? =
  28. 28.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  29. 29.🔺 A 4 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
  30. 30.🧮 A 220 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
  31. 31.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water pressure (b) the water tank lid (c) the tap handle (d) the pipe colour
  32. 32.📏 How many ohms (Ω) is 0.1 kΩ?
  33. 33.🌈 A resistor has the colour bands orange, orange, orange. What is its value (in ohms)?
  34. 34.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 25 % (c) 5 % (d) 50 %
  35. 35.💡 What happens if an LED is put in backwards? (a) it changes colour (b) it makes a sound (c) it does not light (d) it lights brighter
  36. 36.🔺 A current of 3 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  37. 37.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
  38. 38.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 570 Ω resistor? (a) green-violet-red (b) green-violet-black (c) violet-green-brown (d) green-violet-brown
  39. 39.Which of these saves electricity? (a) leave the TV on standby (b) set the AC to 24 °C (c) use old filament bulbs (d) iron one shirt at a time
  40. 40.Which of these is measured in amperes (A)? (a) current (b) voltage (c) power (d) resistance

Answer key

  1. grey-yellow-brown
  2. 12.5
  3. 10
  4. 4
  5. buzzer
  6. V = I × R
  7. False
  8. the flow of charge
  9. 0.25
  10. 22
  11. 0.1
  12. a buzzer
  13. 2
  14. 110
  15. energy used each second
  16. 50
  17. store charge briefly
  18. 1260
  19. 120
  20. may burn out
  21. 1150
  22. 0
  23. 0.1
  24. 450
  25. 9.6
  26. 100
  27. 0.5
  28. saves electricity
  29. 10
  30. 225
  31. the water pressure
  32. 100
  33. 33000
  34. 5 %
  35. it does not light
  36. 18
  37. False
  38. green-violet-brown
  39. set the AC to 24 °C
  40. current

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