← 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 7 · 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 I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V × R (d) I = V + R
  2. 2.🔺 A current of 0.5 A flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  3. 3.🔺 A 7.5 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  4. 4.🔺 A 7.5 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
  5. 5.🔺 A 20 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  6. 6.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = I ÷ V (c) R = V + I (d) R = V × I
  7. 7.🔺 A 3 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
  8. 8.🔺 A 5 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  9. 9.🔺 A current of 3 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
  10. 10.🔺 A current of 2.5 A flows when 37.5 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 A current of 0.5 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  12. 12.🔺 A current of 50 mA flows when 11 V is joined across a resistor. What is its resistance (in ohms)?
  13. 13.🔺 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
  14. 14.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) gets smaller (d) stays the same
  15. 15.🔺 A current of 10 mA flows when 3.3 V is joined across a resistor. What is its resistance (in ohms)?
  16. 16.🔺 A 6 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  17. 17.🔺 A current of 3 A flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
  18. 18.🔺 A current of 40 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
  19. 19.🔺 A current of 2 A flows when 8 V is joined across a resistor. What is its resistance (in ohms)?
  20. 20.🔺 A 16 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  21. 21.🔺 A 1 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  22. 22.🔺 A current of 10 mA flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  23. 23.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  24. 24.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
  25. 25.🔺 A 15 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  26. 26.🔺 A current of 1.5 A flows when 22.5 V is joined across a resistor. What is its resistance (in ohms)?
  27. 27.🔺 A current of 0.2 A flows when 0.6 V is joined across a resistor. What is its resistance (in ohms)?
  28. 28.🔺 A 6 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  29. 29.🔺 A current of 50 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  30. 30.🔺 A 3.3 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
  31. 31.🔺 A current of 2.5 A flows when 15 V is joined across a resistor. What is its resistance (in ohms)?
  32. 32.🔺 A 1.5 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  33. 33.🔺 A current of 2 A flows when 4 V is joined across a resistor. What is its resistance (in ohms)?
  34. 34.🔺 A current of 25 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  36. 36.🔺 A current of 3 A flows when 36 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 A current of 1.5 A flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
  38. 38.🔺 A 3 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  39. 39.🔺 A 3 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
  40. 40.🔺 A 36 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =

Answer key

  1. I = V ÷ R
  2. 5
  3. 25
  4. 2.5
  5. 2
  6. R = V ÷ I
  7. 0.25
  8. 0.25
  9. 4
  10. 15
  11. 4
  12. 220
  13. V = I × R
  14. gets smaller
  15. 330
  16. 40
  17. 2
  18. 150
  19. 4
  20. 2
  21. 0.5
  22. 100
  23. 40
  24. 500
  25. 2.5
  26. 15
  27. 3
  28. 3
  29. 150
  30. 10
  31. 6
  32. 0.25
  33. 2
  34. 120
  35. 20
  36. 12
  37. 5
  38. 20
  39. 25
  40. 3

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