← Ohm’s law: find current and resistance lesson New set →

Electronics Worksheet: Ohm’s Law – Current and Resistance

Electronics lesson 13: Ohm’s law: find current and resistance · Set 685 · 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.🔺 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
  2. 2.🔺 A current of 0.5 A flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
  3. 3.🔺 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
  4. 4.🔺 A 5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  5. 5.🔺 A 7.5 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  6. 6.🔺 A current of 20 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  7. 7.🔺 A current of 2 A flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
  8. 8.🔺 A current of 3 A flows when 9 V is joined across a resistor. What is its resistance (in ohms)?
  9. 9.🔺 A current of 3 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
  10. 10.🔺 A 0.6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  11. 11.🔺 A 5.5 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
  12. 12.🔺 A 0.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  13. 13.🔺 A current of 20 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  14. 14.🔺 A current of 1.5 A flows when 4.5 V is joined across a resistor. What is its resistance (in ohms)?
  15. 15.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets smaller (d) gets bigger
  16. 16.🔺 A 15 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  17. 17.🔺 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
  18. 18.🔺 A current of 0.2 A flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔺 A 5 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  20. 20.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  21. 21.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  22. 22.🔺 A 6.25 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  23. 23.🔺 A 12 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  24. 24.🔺 A current of 20 mA flows when 4.4 V is joined across a resistor. What is its resistance (in ohms)?
  25. 25.🔺 A current of 0.25 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  26. 26.🔺 A 4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  27. 27.🔺 A 60 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  28. 28.🔺 A 5 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  29. 29.🔺 A 3 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  30. 30.🔺 A 23.5 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
  31. 31.🔺 A current of 40 mA flows when 18.8 V is joined across a resistor. What is its resistance (in ohms)?
  32. 32.🔺 A current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  33. 33.🔺 A 15 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  34. 34.🔺 A current of 10 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🔺 A current of 2.5 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  36. 36.🔺 A current of 20 mA flows when 6.6 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 A current of 50 mA flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
  38. 38.🔺 A 25 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  39. 39.🔺 A current of 40 mA flows when 13.2 V is joined across a resistor. What is its resistance (in ohms)?
  40. 40.🔺 A current of 10 mA flows when 1 V is joined across a resistor. What is its resistance (in ohms)?

Answer key

  1. V = I × R
  2. 3
  3. I = V ÷ R
  4. 20
  5. 25
  6. 250
  7. 2
  8. 3
  9. 2
  10. 0.1
  11. 25
  12. 0.1
  13. 100
  14. 3
  15. gets smaller
  16. 2.5
  17. R = V ÷ I
  18. 20
  19. 2.5
  20. 0.1
  21. 20
  22. 25
  23. 3
  24. 220
  25. 8
  26. 1
  27. 3
  28. 10
  29. 1.5
  30. 50
  31. 470
  32. 20
  33. 3
  34. 500
  35. 2
  36. 330
  37. 250
  38. 50
  39. 330
  40. 100

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids