SOLUTION: Ohms law worksheet 1 - Studypool - Free Printable

Absolutely! Let’s solve each problem step-by-step using Ohm’s Law, which states:

> V = I × R
> Where:
> - V = Voltage (in volts, V)
> - I = Current (in amperes, A)
> - R = Resistance (in ohms, Ω)

We can rearrange this formula as needed:
- I = V / R
- R = V / I

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🔹 Problem 1:

An alarm clock draws 0.5 A of current when connected to a 120 volt circuit. Calculate its resistance.

✔ Given:
V = 120 V
I = 0.5 A

Use: R = V / I
→ R = 120 / 0.5 = 240 Ω

✔ Answer: 240 ohms

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🔹 Problem 2:

If a toaster produces 12 ohms of resistance in a 120-volt circuit, what is the amount of current in the circuit?

✔ Given:
V = 120 V
R = 12 Ω

Use: I = V / R
→ I = 120 / 12 = 10 A

✔ Answer: 10 amps

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🔹 Problem 3:

A subwoofer needs a household voltage of 110 V to push a current of 5.5 A through its coil. What is the resistance of the subwoofer?

✔ Given:
V = 110 V
I = 5.5 A

Use: R = V / I
→ R = 110 / 5.5 = 20 Ω

✔ Answer: 20 ohms

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🔹 Problem 4:

A 12 Volt car battery pushes charge through the headlight circuit resistance of 10 ohms. How much current is passing through the circuit?

✔ Given:
V = 12 V
R = 10 Ω

Use: I = V / R
→ I = 12 / 10 = 1.2 A

✔ Answer: 1.2 amps

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🔹 Problem 5:

A walkman uses a standard 1.5 V battery. How much resistance is in the circuit if it uses a current of 0.01 A?

✔ Given:
V = 1.5 V
I = 0.01 A

Use: R = V / I
→ R = 1.5 / 0.01 = 150 Ω

✔ Answer: 150 ohms

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🔹 Problem 6:

How much voltage would be necessary to generate 10 amps of current in a circuit that has 5 ohms of resistance?

✔ Given:
I = 10 A
R = 5 Ω

Use: V = I × R
→ V = 10 × 5 = 50 V

✔ Answer: 50 volts

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🔹 Problem 7:

A circuit contains a 1.5 volt battery and a bulb with a resistance of 3 ohms. Calculate the current.

✔ Given:
V = 1.5 V
R = 3 Ω

Use: I = V / R
→ I = 1.5 / 3 = 0.5 A

✔ Answer: 0.5 amps

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🔹 Problem 8:

An electric heater works by passing a current of 100 A though a coiled metal wire, making it red hot. If the resistance of the wire is 1.1 ohms, what voltage must be applied to it?

✔ Given:
I = 100 A
R = 1.1 Ω

Use: V = I × R
→ V = 100 × 1.1 = 110 V

✔ Answer: 110 volts

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🔹 Problem 9:

What current flows through a hair dryer plugged into a 120 volt circuit if it has a resistance of 25 ohms?

✔ Given:
V = 120 V
R = 25 Ω

Use: I = V / R
→ I = 120 / 25 = 4.8 A

✔ Answer: 4.8 amps

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🔹 Problem 10:

A light bulb has a resistance of 5 ohms and a maximum current of 10 A. How much voltage can be applied before the bulb will break?

✔ Given:
R = 5 Ω
I_max = 10 A

Use: V = I × R
→ V = 10 × 5 = 50 V

✔ Answer: 50 volts (beyond this, the bulb may break)

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🔹 Problem 11:

What happens to the current in a circuit if a 1.5-volt battery is removed and is replaced by a 3-volt battery?
*(Assume resistance stays the same.)*

✔ Ohm’s Law: I = V / R

If V doubles (from 1.5V to 3V) and R is constant, then I also doubles.

✔ Answer: The current doubles.

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🔹 Problem 12:

What happens to the current in a circuit if a 100-ohm resistor is removed and replaced by a 200-ohm resistor?
*(Assume voltage stays the same.)*

✔ Ohm’s Law: I = V / R

If R doubles (from 100Ω to 200Ω) and V is constant, then I halves.

✔ Answer: The current is halved.

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## ✔ Final Summary of Answers:

| Problem | Answer |
|--------|--------|
| 1 | 240 Ω |
| 2 | 10 A |
| 3 | 20 Ω |
| 4 | 1.2 A |
| 5 | 150 Ω |
| 6 | 50 V |
| 7 | 0.5 A |
| 8 | 110 V |
| 9 | 4.8 A |
| 10 | 50 V |
| 11 | Current doubles |
| 12 | Current halves |

Let me know if you’d like these explained visually or with diagrams! 😊