Ohm's Law

Current 1 of 8.4 A runs for 240 seconds and then stops. Current 2 is 10.5 A. How long does current 2 have to run to deliver the same amount of charge as current 1?

192 s

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

192 Ω.

A wire delivers 12.0 C of charge in 4.0 s. What is the current in the wire?

3.0 A

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

4.8 A

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.

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.

Which equation relates charge, time, and current?

a

What is the unit for measuring electric current?

ampere

What is the tendency of a material to oppose the flow of charge?

resistance