Using Ohm’s law for a filament lamp: estimate the filament resistance when the bulb operates from a 110 V source drawing approximately 0.6 A of current.

Introduction / Context:Lamp filaments can be modeled as resistive loads for approximate calculations. Ohm’s law provides a quick way to estimate resistance given operating voltage and current. This is useful for sanity checks and rough power calculations in household or lab settings.

Given Data / Assumptions:

• Supply voltage V = 110 V.
• Operating current I ≈ 0.6 A.
• Treat the filament as a resistor (temperature effects ignored for this estimate).

Concept / Approach:

Use the rearranged Ohm’s law: R = V / I. Keep units consistent, compute the ratio, and round sensibly to match the options. Recognize that a real tungsten filament’s resistance varies with temperature, but the question seeks a steady-state approximate value.

Step-by-Step Solution:

Verification / Alternative check:

Power check: P = V * I = 110 * 0.6 = 66 W (a plausible bulb rating), consistent with a filament around a few hundred ohms at operating temperature.

Why Other Options Are Wrong:

18.3 Ω or 6.6 Ω would imply extremely high current. 66 Ω would imply I ≈ 1.67 A at 110 V (far larger than stated).

Common Pitfalls:

Confusing hot and cold resistance; misplacing the decimal when dividing volts by amps.

Final Answer:

183 Ω