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Electronics Worksheet: Ohm’s Law – Current and Resistance

Electronics lesson 13: Ohm’s law: find current and resistance · Set 677 · 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.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
  2. 2.🔺 A 2.5 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  3. 3.🔺 A 30 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  4. 4.🔺 A current of 25 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  5. 5.🔺 A 10 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  6. 6.🔺 A 2.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  7. 7.🔺 A current of 3 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
  8. 8.🔺 A 3 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  9. 9.🔺 An 8 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  10. 10.🔺 A current of 20 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 A 3.75 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  12. 12.🔺 A 3 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  13. 13.🔺 A 50 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  14. 14.🔺 In the V-I-R triangle, how do we find V? (a) V = I ÷ R (b) V = I + R (c) V = I × R (d) V = R ÷ I
  15. 15.🔺 A 15 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  16. 16.🔺 A 3 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  17. 17.🔺 A 60 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  18. 18.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = V ÷ I (c) R = V × I (d) R = I ÷ V
  19. 19.🔺 A 0.4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  20. 20.🔺 A current of 0.2 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  21. 21.🔺 A current of 50 mA flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
  22. 22.🔺 A 4.4 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
  23. 23.🔺 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
  24. 24.🔺 A current of 25 mA flows when 3.75 V is joined across a resistor. What is its resistance (in ohms)?
  25. 25.🔺 A 22.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  26. 26.🔺 A current of 10 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  27. 27.🔺 A current of 50 mA flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
  28. 28.🔺 A 5 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  29. 29.🔺 A 1.5 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  30. 30.🔺 A 4.8 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  31. 31.🔺 A current of 10 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  32. 32.🔺 A current of 1 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  33. 33.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  34. 34.🔺 A current of 0.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🔺 A 1 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  36. 36.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 A 1 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  38. 38.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  39. 39.🔺 A 4 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  40. 40.🔺 A 9 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =

Answer key

  1. gets smaller
  2. 25
  3. 2
  4. 300
  5. 0.5
  6. 0.5
  7. 5
  8. 0.2
  9. 2
  10. 100
  11. 0.25
  12. 0.5
  13. 2.5
  14. V = I × R
  15. 50
  16. 0.25
  17. 3
  18. R = V ÷ I
  19. 0.1
  20. 5
  21. 250
  22. 20
  23. I = V ÷ R
  24. 150
  25. 1.5
  26. 200
  27. 500
  28. 25
  29. 10
  30. 40
  31. 250
  32. 10
  33. 20
  34. 15
  35. 10
  36. 500
  37. 0.2
  38. 0.2
  39. 20
  40. 3

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