Electronics Worksheet: Ohm’s Law – Find the Voltage
Remember (V on top): V = I × R (volts = amperes × ohms). Change mA to A first: 20 mA = 0.02 A. Example: 0.02 A × 220 Ω = 4.4 V.
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- 1.🔺 A current of 1.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
- 2.🔺 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
- 3.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) becomes zero (d) gets smaller
- 4.🔺 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
- 5.🔺 A current of 20 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
- 6.🔺 A current of 1.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
- 7.🔺 A current of 2.5 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
- 8.🔺 A current of 2.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
- 9.🔺 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
- 10.🔺 A current of 50 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
- 11.🔺 A current of 40 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
- 12.🔺 A current of 2 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
- 13.🔺 A current of 2 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
- 14.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
- 15.🔺 A current of 0.2 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
- 16.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
- 17.🔺 A current of 10 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
- 18.🔺 A current of 0.1 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
- 19.🔺 A current of 25 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
- 20.🔺 A current of 0.25 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
- 21.🔺 A current of 50 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
- 22.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
- 23.🔺 A current of 3 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
- 24.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
- 25.🔺 A current of 0.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
- 26.🔺 A current of 2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
- 27.🔺 A current of 2.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
- 28.🔺 A current of 25 mA flows through a 400 Ω resistor. What is the voltage across it (in volts)? =
- 29.🔺 A current of 20 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
- 30.🔺 A current of 3 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
- 31.🔺 A current of 0.2 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
- 32.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
- 33.🔺 A current of 50 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
- 34.🔺 A current of 20 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
- 35.🔺 A current of 0.2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
- 36.🔺 A current of 1.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
- 37.🔺 A current of 3 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
- 38.🔺 A current of 50 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
- 39.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
- 40.🔺 A current of 2.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
Answer key
- 22.5
- V = I × R
- gets smaller
- I = V ÷ R
- 4
- 18
- 25
- 37.5
- R = V ÷ I
- 12.5
- 4
- 4
- 6
- 5
- 1
- 6
- 2.2
- 0.3
- 3
- 1.5
- 15
- 2
- 30
- 10
- 7.5
- 8
- 30
- 10
- 10
- 45
- 0.6
- 2
- 10
- 9.4
- 4
- 30
- 18
- 25
- 3
- 12.5
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