Ohm's Law Self-Guided Lesson

Multiple Choice

What is the significance of Ohm's Law in understanding electrical circuits?

• It helps in calculating power consumption only.

• It is used to determine the relationship between resistance, voltage, and current.

• It is only applicable to alternating current circuits.

• It is not used in practical applications.

Open Ended

A 0.686 meter long wire has a cross sectional area of 8.23 x 10^-6 m^2 and a resistance of 0.125 ohm at 20°C. What could the wire be made of?

Fill in the Blanks

Do you have any questions about solving for resistance, voltage, or current using Ohm’s Law, or would you like to learn more about its applications?

Multiple Choice

In a simple electric circuit, a 110-volt electric heater draws 2.0 amperes of current. The resistance of the heater is

• 55 ohms
• 30 ohms
• 120 ohms

• 100 ohms

Multiple Choice

In a simple electric circuit, a 24-ohm resistor is connected across a 6.0-volt battery. What is the current in the circuit?

• 0.5 A
• 0.75 A
• 0.25 A
• 1.0 A

Multiple Choice

The current through a 10.-ohm resistor is 1.2 amperes. What is the potential difference across the resistor?

• 12 volts
• 10 volts
• 15 volts
• 8 volts

Open Ended

In a circuit, a 100.-ohm resistor and a 200.-ohm resistor are connected in parallel to a 10.0-volt battery. Calculate the current in the 200.-ohm resistor. [Show all work, including the equation and substitution with units.]

Multiple Choice

A potential difference of 60 volts is applied across a 15 ohm resistor. What is the power dissipated in the resistor?

• 240 watts
• 300 watts
• 180 watts
• 120 watts

Multiple Choice

A current of 0.40 amps is measured in a 150 ohm resistor. What is the total energy expended by the resistor in 30 seconds?

• 480 joules
• 720 joules
• 600 joules
• 360 joules

Multiple Choice

How much time is needed for an operating 100 watt incandescent lightbulb to dissipate 10 joules of electrical energy?

• 2 seconds
• 0.5 seconds
• 1 second
• 0.1 seconds