1. What are the key points to Ohm’s Law?
2. A 15 ohm resistor is connected across a 3 V supply. What is the current?
3. Look at the voltage current graph:
Why does the line go through the origin?
What does the gradient tell us?
4. Why is the graph of a light bulb shaped like this?
5. A lamp takes a current of 0.3 A at a voltage of 6 V. What is its resistance? Some students measure the resistance of the lamp with an ohmmeter and find that the resistance is only 4 ohms. Explain why this happens.