Practice Ohm's Law in Physics

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

The fundamental relationship stating that the voltage (V) across an ohmic conductor equals the current (I) flowing through it multiplied by its resistance (R).

More push (voltage) means more flow (current). More resistance means less flow for the same push.

Example 1

easy
A 12 \text{ V} battery is connected to a 4 \text{ } \Omega resistor. What current flows?

Example 2

medium
A heater draws 5 \text{ A} from a 240 \text{ V} supply. What is its resistance, and how much power does it consume?

Example 3

medium
What voltage is needed to push 0.25 \text{ A} through a 100 \text{ } \Omega resistor?

Example 4

medium
A resistor in a circuit has a current of 0.5 \text{ A} flowing through it when connected to a 6 \text{ V} supply. (a) What is its resistance? (b) If the voltage is doubled to 12 \text{ V}, what is the new current (assuming constant resistance)?
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