← 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 936 · 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.🧮 Resistors of 10 Ω and 47 Ω are joined in series. What is the total resistance (in ohms)?
  2. 2.True or false: on an LED, the longer leg is the cathode (−). (a) False (b) True
  3. 3.⚡ A device works on 3 V and takes 2 A. What is its power (in watts)? =
  4. 4.🔺 A current of 1.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
  5. 5.🔺 A current of 0.1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  6. 6.What does a transistor do? (a) boosts a small signal (b) stores a little charge (c) makes a beeping sound (d) has coloured bands
  7. 7.🔺 A current of 0.1 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  8. 8.📏 How many amperes (A) is 780 mA? =
  9. 9.⚡ A home appliance on the 230 V mains takes 8 A. What is its power (in watts)?
  10. 10.🧮 Four equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  11. 11.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  12. 12.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
  13. 13.What does an LED do? (a) blows if current is high (b) turns a fan or wheels (c) glows using little power (d) stores a little charge
  14. 14.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) smaller (c) bigger (d) zero
  15. 15.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) less than either one (c) always zero (d) their sum
  16. 16.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  17. 17.What does an LDR do? (a) blows if current is high (b) senses how bright it is (c) senses how hot it is (d) beeps for an alarm
  18. 18.🔺 A current of 1.5 A flows when 18 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔺 A current of 0.2 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  20. 20.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
  21. 21.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = I ÷ V (d) R = V + I
  22. 22.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  23. 23.🔺 A current of 40 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
  24. 24.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
  25. 25.🧮 Resistors of 10 Ω, 50 Ω and 100 Ω are joined in series. What is the total resistance (in ohms)?
  26. 26.🔺 A current of 50 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  27. 27.🌈 A resistor has the colour bands yellow, black, yellow. What is its value in kilo-ohms (kΩ)? =
  28. 28.🔺 A current of 20 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
  29. 29.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
  30. 30.What does a buzzer do? (a) senses how bright it is (b) stores a little charge (c) blows if current is high (d) makes a beeping sound
  31. 31.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) an LED lamp (c) a filament bulb (d) a candle
  32. 32.🌈 In the resistor colour code, which number does white stand for?
  33. 33.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to an 8 V supply. What current flows (in mA)?
  34. 34.📏 Which unit measures current? (a) watt (W) (b) ohm (Ω) (c) volt (V) (d) ampere (A)
  35. 35.🧾 A family uses 70 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  36. 36.🧩 Which component makes a beeping sound? (a) thermistor (b) motor (c) buzzer (d) diode
  37. 37.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  38. 38.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) stays the same (d) becomes zero
  39. 39.🔺 A current of 1 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
  40. 40.🔺 A 1.2 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =

Answer key

  1. 57
  2. False
  3. 6
  4. 12
  5. 1.5
  6. boosts a small signal
  7. 0.2
  8. 0.78
  9. 1840
  10. 50
  11. 204
  12. 5.5
  13. glows using little power
  14. bigger
  15. less than either one
  16. 1
  17. senses how bright it is
  18. 12
  19. 3
  20. cathode (−)
  21. R = V ÷ I
  22. 408
  23. 18.8
  24. energy used each second
  25. 160
  26. 25
  27. 400
  28. 8
  29. 115
  30. makes a beeping sound
  31. an LED lamp
  32. 9
  33. 20
  34. ampere (A)
  35. 350
  36. buzzer
  37. 25
  38. gets smaller
  39. 12
  40. 0.1

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