Electric Current and Ohm's Law

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

• 60Ω

• 120Ω

• 180Ω

• 240Ω

Speakers need a household voltage of 110 V to push a current of 5.5 A through them. What is the resistance of the speakers?

• 10Ω

• 20Ω

• 30Ω

• 40Ω

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

• 50Ω

• 100Ω

• 150Ω

• 200Ω

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

• 0.5A

• 1A

• 1.5A

• 2A

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

• 2.4A

• 3.6A

• 4.8A

• 6A

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

circuit?

• 5A

• 10A

• 15A

• 20A

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

is passing through the circuit?

• 1A

• 1.2A

• 1.4A

• 1.6A

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?

• 70V

• 90V

• 110V

• 130V

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?

• 5V

• 10V

• 25V

• 50V

What is the potential difference across an electrical load that has a resistance of 4 Ω and a current of 3 A flowing through it?

• 4V

• 8V

• 12V

• 16V