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?

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