A lamp has a source voltage of 110 volts and a current of 0.9 amps. What is the resistance of the lamp?

To determine the resistance of the lamp, Ohm's Law is used, which states that resistance (R) is equal to voltage (V) divided by current (I). In this scenario, the voltage provided is 110 volts, and the current is 0.9 amps.

Using the formula R = V / I:

1. Substitute the known values: R = 110 volts / 0.9 amps.

2. Perform the division: R = 122.22 ohms.

This calculation shows that the resistance of the lamp is 122.22 ohms, which aligns with the correct answer choice. Understanding this calculation is vital because it lays the foundation for many applications in electrical engineering and everyday electronics, emphasizing how voltage and current relate to resistance in circuits.