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Electronics Worksheet: Components and Ohm’s Law Test

Electronics lesson 20: Part 2 test: components and Ohm’s law · Set 471 · 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.🌈 Which band is read first on a resistor? (a) the widest gap (b) the gold band (c) any band (d) the one nearest an end
  2. 2.🔺 A 2.4 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  3. 3.🔺 A current of 40 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
  4. 4.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
  5. 5.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  6. 6.🌈 A resistor has the colour bands yellow, yellow, yellow. What is its value in kilo-ohms (kΩ)? =
  7. 7.🔺 A current of 0.1 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
  8. 8.⚡ Power tells us … (a) the size of a cell (b) the length of a wire (c) energy used each second (d) the colour of light
  9. 9.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)
  10. 10.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 0 % (c) 50 % (d) 25 %
  11. 11.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it does not light (c) it changes colour (d) it makes a sound
  12. 12.📏 Which unit measures power? (a) ampere (A) (b) watt (W) (c) volt (V) (d) ohm (Ω)
  13. 13.🔺 A 2 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  14. 14.🌈 A resistor has the colour bands yellow, red, brown. What is its value (in ohms)?
  15. 15.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 17 Ω resistor? (a) red-violet-black (b) brown-violet-brown (c) violet-brown-black (d) brown-violet-black
  16. 16.🔺 A 7.5 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  17. 17.🔺 A current of 3 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
  18. 18.🧩 Which component blows if current is high? (a) resistor (b) fuse (c) thermistor (d) capacitor
  19. 19.📏 How many watts (W) is 2.2 kW?
  20. 20.True or false: a buzzer beeps for an alarm. (a) True (b) False
  21. 21.🔍 Which is the odd one out? (a) leave the TV on standby (b) use old filament bulbs (c) leave fridge door open (d) use LED lamps
  22. 22.🔺 A current of 1.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  23. 23.🔺 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
  24. 24.🧮 Five equal 500 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  25. 25.Which of these saves electricity? (a) run fans in empty rooms (b) use old filament bulbs (c) leave fridge door open (d) switch off empty rooms
  26. 26.🧾 A family uses 30 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  27. 27.🧩 Which component has coloured bands? (a) motor (b) potentiometer (c) resistor (d) capacitor
  28. 28.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = V + R (c) I = V ÷ R (d) I = R ÷ V
  29. 29.🔺 A 5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  30. 30.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
  31. 31.🔺 A current of 0.2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
  32. 32.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 100 (b) 10 (c) 1024 (d) 1000
  33. 33.🧾 A family uses 160 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  34. 34.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
  35. 35.🔺 A current of 1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
  36. 36.⚡ A device works on 5 V and takes 1.5 A. What is its power (in watts)? =
  37. 37.🔺 A current of 0.5 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
  38. 38.🔺 A 45 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  39. 39.📏 Voltmeter or ammeter: which one is joined in series? (a) ammeter (b) voltmeter
  40. 40.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) bigger (d) stay the same

Answer key

  1. the one nearest an end
  2. 0.2
  3. 13.2
  4. True
  5. anode (+)
  6. 440
  7. 0.6
  8. energy used each second
  9. 1 kilowatt-hour (kWh)
  10. 5 %
  11. it does not light
  12. watt (W)
  13. 0.25
  14. 420
  15. brown-violet-black
  16. 50
  17. 24
  18. fuse
  19. 2200
  20. True
  21. use LED lamps
  22. 3
  23. V = I × R
  24. 100
  25. switch off empty rooms
  26. 270
  27. resistor
  28. I = V ÷ R
  29. 10
  30. cathode (−)
  31. 0.4
  32. 1000
  33. 1440
  34. 20
  35. 10
  36. 7.5
  37. 1.5
  38. 3
  39. ammeter
  40. bigger

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