Ohms Ohms Ohms

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

According to Ohm's Law, if you were to double the voltage and double the resistance, what would happen to the flow of current?

• It would stay the same

• It would increase 2x

• It would increase 4x

• It would decrease 2x

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

• 60Ω

• 120Ω

• 180Ω

• 240Ω

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

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

Calculate the current an electric clothes dryer draws when it is connected to a 230 V source and has a resistance

of 9.2 Ω.

• 5A

• 15A

• 25A

• 35A

A portable radio connected to a 9.0 V battery draws a current of 25 A. What is the resistance of the radio?

• 0.036Ω

• 0.36Ω

• 3.6Ω

• 36Ω

How much resistance does a heavy duty flashlight have if it has a current of 25 mA flowing through it and is being

powered by four 1.5 V cells?

• 0.15Ω

• 1.5Ω

• 15Ω

• 150Ω

If the voltage is 18 volts and the current is 6 amps, what is the resistance?

• 9 ohms

• 12 ohms

• 5 ohms

• 3 ohms