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Electronics Worksheet: Ohm’s Law – Current and Resistance

Electronics lesson 13: Ohm’s law: find current and resistance · Set 324 · 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.

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  1. 1.🔺 A current of 0.25 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  2. 2.🔺 A 30 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  3. 3.🔺 A 4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  4. 4.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V + R (c) I = V × R (d) I = V ÷ R
  5. 5.🔺 A 0.6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  6. 6.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  7. 7.🔺 A 1 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  8. 8.🔺 A current of 10 mA flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  9. 9.🔺 A 0.5 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  10. 10.🔺 A current of 40 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 A current of 10 mA flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
  12. 12.🔺 A current of 25 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  13. 13.🔺 A 6.25 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  14. 14.🔺 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
  15. 15.🔺 A 2 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  16. 16.🔺 A 2.5 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  17. 17.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  18. 18.🔺 A 7.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  19. 19.🔺 A 25 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  20. 20.🔺 A 1.5 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  21. 21.🔺 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
  22. 22.🔺 A current of 25 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  23. 23.🔺 A 5 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  24. 24.🔺 A 0.4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  25. 25.🔺 A current of 40 mA flows when 18.8 V is joined across a resistor. What is its resistance (in ohms)?
  26. 26.🔺 A current of 10 mA flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
  27. 27.🔺 A current of 20 mA flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
  28. 28.🔺 A 1.2 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  29. 29.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  30. 30.🔺 A 0.8 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  31. 31.🔺 A 12 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  32. 32.🔺 A 3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  33. 33.🔺 A 30 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  34. 34.🔺 A current of 10 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🔺 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
  36. 36.🔺 A current of 0.2 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 A current of 40 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
  38. 38.🔺 A current of 2.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  39. 39.🔺 A current of 50 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  40. 40.🔺 A 6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =

Answer key

  1. 8
  2. 2
  3. 1
  4. I = V ÷ R
  5. 0.1
  6. 500
  7. 0.1
  8. 100
  9. 0.25
  10. 100
  11. 150
  12. 300
  13. 25
  14. gets smaller
  15. 20
  16. 0.25
  17. 0.1
  18. 0.5
  19. 50
  20. 0.25
  21. V = I × R
  22. 100
  23. 50
  24. 0.1
  25. 470
  26. 120
  27. 400
  28. 10
  29. 20
  30. 0.2
  31. 2
  32. 1
  33. 1.5
  34. 300
  35. R = V ÷ I
  36. 4
  37. 150
  38. 3
  39. 100
  40. 2

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