← 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 535 · 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 R? (a) R = I ÷ V (b) R = V × I (c) R = V + I (d) R = V ÷ I
  2. 2.🔺 A 15 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  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 current of 25 mA flows when 6.25 V is joined across a resistor. What is its resistance (in ohms)?
  5. 5.🔺 A current of 0.25 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  6. 6.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I × R (d) V = I ÷ R
  7. 7.🔺 A current of 2.5 A flows when 37.5 V is joined across a resistor. What is its resistance (in ohms)?
  8. 8.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) stays the same (d) gets smaller
  9. 9.🔺 A 1.5 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  10. 10.🔺 A current of 2.5 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 A 60 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  12. 12.🔺 A current of 2.5 A flows when 50 V is joined across a resistor. What is its resistance (in ohms)?
  13. 13.🔺 A current of 0.1 A flows when 0.6 V is joined across a resistor. What is its resistance (in ohms)?
  14. 14.🔺 An 18 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  15. 15.🔺 A 12.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  16. 16.🔺 A 3.75 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  17. 17.🔺 A current of 0.1 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
  18. 18.🔺 A current of 40 mA flows when 18.8 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔺 An 18 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  20. 20.🔺 A current of 0.2 A flows when 2.4 V is joined across a resistor. What is its resistance (in ohms)?
  21. 21.🔺 A 2 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  22. 22.🔺 A 16 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  23. 23.🔺 A current of 3 A flows when 60 V is joined across a resistor. What is its resistance (in ohms)?
  24. 24.🔺 A current of 40 mA flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
  25. 25.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  26. 26.🔺 A 0.8 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  27. 27.🔺 A current of 0.2 A flows when 0.4 V is joined across a resistor. What is its resistance (in ohms)?
  28. 28.🔺 A 0.4 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  29. 29.🔺 A current of 40 mA flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
  30. 30.🔺 A current of 0.1 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  31. 31.🔺 A 2 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  32. 32.🔺 A 6 V supply is joined across a 4 Ω resistor. What current flows (in amperes)? =
  33. 33.🔺 A current of 25 mA flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  34. 34.🔺 A 0.3 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  35. 35.🔺 A 2.4 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  36. 36.🔺 A 1.25 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  37. 37.🔺 A 7.5 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  38. 38.🔺 A 22.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  39. 39.🔺 A 3 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  40. 40.🔺 A 5 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =

Answer key

  1. R = V ÷ I
  2. 1
  3. I = V ÷ R
  4. 250
  5. 20
  6. V = I × R
  7. 15
  8. gets smaller
  9. 10
  10. 12
  11. 3
  12. 20
  13. 6
  14. 1.5
  15. 50
  16. 0.25
  17. 8
  18. 470
  19. 3
  20. 12
  21. 0.5
  22. 2
  23. 20
  24. 200
  25. 0.2
  26. 0.1
  27. 2
  28. 0.1
  29. 100
  30. 10
  31. 20
  32. 1.5
  33. 100
  34. 0.1
  35. 20
  36. 0.25
  37. 25
  38. 1.5
  39. 1.5
  40. 0.5

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