← 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 105 · 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 0.4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  2. 2.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V × R (c) I = R ÷ V (d) I = V ÷ R
  3. 3.🔺 A current of 25 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  4. 4.🔺 A 24 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  5. 5.🔺 A current of 0.25 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  6. 6.🔺 A current of 10 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  7. 7.🔺 A 45 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  8. 8.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets bigger (d) gets smaller
  9. 9.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = R ÷ I (c) V = I + R (d) V = I ÷ R
  10. 10.🔺 A current of 40 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 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
  12. 12.🔺 A current of 0.25 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  13. 13.🔺 A current of 0.5 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  14. 14.🔺 A 30 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  15. 15.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  16. 16.🔺 A 1.25 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  17. 17.🔺 An 11 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
  18. 18.🔺 A current of 50 mA flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔺 A current of 2.5 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  20. 20.🔺 A 0.8 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  21. 21.🔺 A 1 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  22. 22.🔺 A 12 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  23. 23.🔺 A 2.5 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  24. 24.🔺 A 2 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  25. 25.🔺 A current of 25 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  26. 26.🔺 A 2.4 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  27. 27.🔺 A 5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  28. 28.🔺 A 3 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  29. 29.🔺 A 25 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
  30. 30.🔺 A 2.4 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  31. 31.🔺 A current of 1.5 A flows when 4.5 V is joined across a resistor. What is its resistance (in ohms)?
  32. 32.🔺 A 4 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  33. 33.🔺 A current of 40 mA flows when 8.8 V is joined across a resistor. What is its resistance (in ohms)?
  34. 34.🔺 A 0.2 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  35. 35.🔺 A current of 1 A flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
  36. 36.🔺 A current of 0.2 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 A current of 25 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  38. 38.🔺 A current of 3 A flows when 18 V is joined across a resistor. What is its resistance (in ohms)?
  39. 39.🔺 A 10 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  40. 40.🔺 A current of 50 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?

Answer key

  1. 0.1
  2. I = V ÷ R
  3. 300
  4. 2
  5. 8
  6. 200
  7. 3
  8. gets smaller
  9. V = I × R
  10. 150
  11. R = V ÷ I
  12. 20
  13. 2
  14. 2.5
  15. 0.2
  16. 0.25
  17. 50
  18. 500
  19. 8
  20. 0.2
  21. 10
  22. 2
  23. 0.25
  24. 20
  25. 400
  26. 20
  27. 20
  28. 10
  29. 50
  30. 0.2
  31. 3
  32. 20
  33. 220
  34. 0.1
  35. 3
  36. 2
  37. 200
  38. 6
  39. 50
  40. 120

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