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Electronics Worksheet: Ohm’s Law – Current and Resistance

Electronics lesson 13: Ohm’s law: find current and resistance · Set 634 · 40 questions
TalentJR

Remember (Cover what you want): I = V ÷ R (amperes = volts ÷ ohms). R = V ÷ I (ohms = volts ÷ amperes); use amperes, not mA, in the formula. Example: 5 V and 25 mA (0.025 A) → R = 5 ÷ 0.025 = 200 Ω.

NameDateTime takenScore ___ / 40
  1. 1.🔺 A current of 25 mA flows when 5.5 V is joined across a resistor. What is its resistance (in ohms)?
  2. 2.🔺 A current of 0.5 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  3. 3.🔺 A current of 3 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
  4. 4.🔺 A current of 2 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  5. 5.🔺 An 8.8 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
  6. 6.🔺 A current of 0.2 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
  7. 7.🔺 A 36 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  8. 8.🔺 A current of 50 mA flows when 11 V is joined across a resistor. What is its resistance (in ohms)?
  9. 9.🔺 A 12 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  10. 10.🔺 A current of 0.2 A flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 A current of 40 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  12. 12.🔺 A current of 40 mA flows when 18.8 V is joined across a resistor. What is its resistance (in ohms)?
  13. 13.🔺 A current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  14. 14.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I ÷ R (c) V = R ÷ I (d) V = I + R
  15. 15.🔺 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
  16. 16.🔺 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
  17. 17.🔺 A 13.2 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
  18. 18.🔺 A current of 50 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔺 A 0.8 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  20. 20.🔺 A 0.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  21. 21.🔺 A current of 1 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
  22. 22.🔺 A current of 3 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
  23. 23.🔺 A current of 0.1 A flows when 0.3 V is joined across a resistor. What is its resistance (in ohms)?
  24. 24.🔺 An 18 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  25. 25.🔺 A 3 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  26. 26.🔺 A current of 0.1 A flows when 0.5 V is joined across a resistor. What is its resistance (in ohms)?
  27. 27.🔺 A current of 40 mA flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
  28. 28.🔺 A current of 2.5 A flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
  29. 29.🔺 A current of 3 A flows when 24 V is joined across a resistor. What is its resistance (in ohms)?
  30. 30.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  31. 31.🔺 A current of 50 mA flows when 23.5 V is joined across a resistor. What is its resistance (in ohms)?
  32. 32.🔺 A 0.4 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  33. 33.🔺 A current of 50 mA flows when 16.5 V is joined across a resistor. What is its resistance (in ohms)?
  34. 34.🔺 A current of 2.5 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🔺 A 0.6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  36. 36.🔺 A current of 0.25 A flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 A 6 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  38. 38.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  39. 39.🔺 A current of 20 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  40. 40.🔺 A 20 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =

Answer key

  1. 220
  2. 2
  3. 4
  4. 5
  5. 40
  6. 4
  7. 3
  8. 220
  9. 1.5
  10. 20
  11. 500
  12. 470
  13. 20
  14. V = I × R
  15. I = V ÷ R
  16. R = V ÷ I
  17. 40
  18. 400
  19. 0.2
  20. 0.1
  21. 12
  22. 10
  23. 3
  24. 3
  25. 25
  26. 5
  27. 300
  28. 10
  29. 8
  30. 0.1
  31. 470
  32. 0.2
  33. 330
  34. 8
  35. 0.2
  36. 10
  37. 40
  38. 40
  39. 100
  40. 1

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