Ohm's Law

Which changes would cause an increase in the resistance of a wire? Check all that apply.

* increasing its temperature * Using a longer wire * using a thinner wire

A circuit has a current of 3.6 A and a resistance of 5.0 Ω. What is the voltage applied to the circuit?

18V

A ceiling fan draws a current of 0.625 A and has a voltage of 120 V. The resistance of the ceiling fan, to the nearest whole number, is _____ Ω.

192

A circuit has a resistance of 2.5 Ω and is powered by a 12.0 V battery. The current in the circuit, to the nearest tenth, is _____ A.

4.8

In 12 s, a wire delivers 96 C of charge. The current in the wire, to the nearest whole number, is _____ A.

8

Which equation relates charge, time, and current?

I = Δq/t

Cici uses a long extension cord to plug a lamp into a wall outlet in the next room. What effect will the extension cord have on the circuit?

It will increase the resistance in the circuit.

What is the unit for resistance?

Ohm (Ω)

For a constant voltage, how is the resistance related to the current?

Resistance is inversely proportional to current, so when the resistance doubles, the current is cut in half.

Jason sees a news report about a traffic jam caused by a truckload of tires that spilled across the road. The next day in class, he uses the traffic jam as an analogy to explain electric circuits to his friend. Which is most likely the analogy that Jason used?

The cars represent moving charges, and the spilled tires represent an increased resistance that causes the current to decrease.