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Electronics Worksheet: Ohm’s Law – Current and Resistance

Electronics lesson 13: Ohm’s law: find current and resistance · Set 177 · 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 10 mA flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
  2. 2.🔺 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
  3. 3.🔺 A current of 0.1 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
  4. 4.🔺 A current of 0.5 A flows when 2.5 V is joined across a resistor. What is its resistance (in ohms)?
  5. 5.🔺 A 10 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
  6. 6.🔺 A 7.5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  7. 7.🔺 A 1.6 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
  8. 8.🔺 A 1.25 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  9. 9.🔺 A 25 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  10. 10.🔺 A current of 0.1 A flows when 0.8 V is joined across a resistor. What is its resistance (in ohms)?
  11. 11.🔺 A current of 20 mA flows when 2.4 V is joined across a resistor. What is its resistance (in ohms)?
  12. 12.🔺 A 0.2 V supply is joined across a 2 Ω resistor. What current flows (in amperes)? =
  13. 13.🔺 A current of 10 mA flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
  14. 14.🔺 A 3.75 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  15. 15.🔺 A 10 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  16. 16.🔺 A 12 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
  17. 17.🔺 A current of 10 mA flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
  18. 18.🔺 A 16 V supply is joined across a 400 Ω resistor. What current flows (in milliamperes, mA)?
  19. 19.🔺 A 1.5 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  20. 20.🔺 A 6 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
  21. 21.🔺 A 5 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
  22. 22.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets smaller (d) gets bigger
  23. 23.🔺 A current of 50 mA flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
  24. 24.🔺 A 0.6 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
  25. 25.🔺 A 3 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
  26. 26.🔺 A 4.7 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
  27. 27.🔺 A 5 V supply is joined across a 5 Ω resistor. What current flows (in amperes)? =
  28. 28.🔺 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
  29. 29.🔺 A 2.5 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
  30. 30.🔺 A 12.5 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?
  31. 31.🔺 A 5 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
  32. 32.🔺 A current of 0.2 A flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
  33. 33.🔺 A current of 2 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  34. 34.🔺 A current of 50 mA flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  35. 35.🔺 A current of 1 A flows when 20 V is joined across a resistor. What is its resistance (in ohms)?
  36. 36.🔺 A current of 3 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
  37. 37.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = V + I (d) R = I ÷ V
  38. 38.🔺 A current of 10 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
  39. 39.🔺 A 4 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
  40. 40.🔺 A current of 0.1 A flows when 0.3 V is joined across a resistor. What is its resistance (in ohms)?

Answer key

  1. 200
  2. V = I × R
  3. 10
  4. 5
  5. 25
  6. 1.5
  7. 0.2
  8. 0.25
  9. 2.5
  10. 8
  11. 120
  12. 0.1
  13. 150
  14. 25
  15. 50
  16. 40
  17. 120
  18. 40
  19. 0.1
  20. 40
  21. 0.25
  22. gets smaller
  23. 500
  24. 0.1
  25. 0.2
  26. 10
  27. 1
  28. I = V ÷ R
  29. 0.25
  30. 50
  31. 50
  32. 6
  33. 10
  34. 400
  35. 20
  36. 4
  37. R = V ÷ I
  38. 500
  39. 20
  40. 3

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