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Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 332 · 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.

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  1. 1.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) becomes zero (d) stays the same
  2. 2.🌈 Which band is read first on a resistor? (a) the one nearest an end (b) any band (c) the gold band (d) the widest gap
  3. 3.🌈 In the resistor colour code, which number does black stand for?
  4. 4.⚡ A device works on 5 V and takes 0.1 A. What is its power (in watts)? =
  5. 5.⚡ A device works on 12 V and takes 0.25 A. What is its power (in watts)? =
  6. 6.🔺 A current of 3 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
  7. 7.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) use daylight to read (c) switch off empty rooms (d) use old filament bulbs
  8. 8.🌈 A resistor has the colour bands yellow, green, yellow. What is its value in kilo-ohms (kΩ)? =
  9. 9.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V × I (c) R = V + I (d) R = V ÷ I
  10. 10.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 3600 Ω resistor? (a) orange-blue-brown (b) orange-blue-orange (c) orange-blue-red (d) blue-orange-red
  11. 11.Which of these is measured in ohms (Ω)? (a) the flow of charge (b) current (c) resistance (d) power
  12. 12.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 380 Ω resistor? (a) grey-orange-brown (b) orange-grey-brown (c) orange-grey-black (d) orange-grey-red
  13. 13.🔺 A current of 0.1 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
  14. 14.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) True (b) False
  15. 15.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =
  16. 16.🧾 A family uses 30 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  17. 17.🔺 A current of 25 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
  18. 18.🧮 A 1.6 V battery is joined to 5 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
  19. 19.🔺 A current of 10 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  20. 20.Which of these wastes electricity? (a) close the fridge quickly (b) use LED lamps (c) use old filament bulbs (d) use daylight to read
  21. 21.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 1600 Ω resistor? (a) brown-blue-red (b) blue-brown-red (c) brown-blue-brown (d) brown-blue-orange
  22. 22.📏 How many watts (W) is 1.1 kW?
  23. 23.🔺 A current of 50 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  24. 24.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) more than either one (d) less than either one
  25. 25.🌈 In the resistor colour code, which number does violet stand for?
  26. 26.🧩 Which part changes electrical energy into movement? (a) an LED (b) a resistor (c) a fuse (d) a motor
  27. 27.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 50000 Ω resistor? (a) green-black-yellow (b) green-black-red (c) blue-green-orange (d) green-black-orange
  28. 28.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
  29. 29.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
  30. 30.🌈 A resistor has the colour bands grey, blue, yellow. What is its value in kilo-ohms (kΩ)? =
  31. 31.True or false: a potentiometer has coloured bands. (a) False (b) True
  32. 32.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
  33. 33.🔺 A current of 10 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
  34. 34.🌈 In the resistor colour code, which number does orange stand for?
  35. 35.🔍 Which is the odd one out? (a) use old filament bulbs (b) iron one shirt at a time (c) set the AC to 24 °C (d) leave the TV on standby
  36. 36.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  37. 37.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
  38. 38.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) use LED lamps (d) iron one shirt at a time
  39. 39.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 5 % (d) 50 %
  40. 40.🌈 A resistor has the colour bands red, white, black. What is its value (in ohms)?

Answer key

  1. gets smaller
  2. the one nearest an end
  3. 0
  4. 0.5
  5. 3
  6. 12
  7. use old filament bulbs
  8. 450
  9. R = V ÷ I
  10. orange-blue-red
  11. resistance
  12. orange-grey-brown
  13. 1.5
  14. True
  15. 0.3
  16. 180
  17. 2.5
  18. 0.2
  19. 500
  20. use old filament bulbs
  21. brown-blue-red
  22. 1100
  23. 7.5
  24. less than either one
  25. 7
  26. a motor
  27. green-black-orange
  28. True
  29. 100
  30. 860
  31. False
  32. 3
  33. 5
  34. 3
  35. set the AC to 24 °C
  36. saves electricity
  37. saves electricity
  38. use LED lamps
  39. 5 %
  40. 29

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