What is the resistance of a lamp that operates on 300 volts and draws 25 milliamps?

• A. 600 Ω
• B. 12,000 Ω
• C. 1,200 Ω
• D. 300 Ω

Answer: (B)

To determine the resistance of the lamp, Ohm's Law can be applied, which states that resistance (R) is equal to voltage (V) divided by current (I). In this case, the voltage is given as 300 volts, and the current is 25 milliamps.

First, we convert the current from milliamps to amps: 25 milliamps is equal to 0.025 amps (since 1 milliamp is 0.001 amps).

Now apply Ohm's Law:

[ R = \frac{V}{I} = \frac{300 \text{ volts}}{0.025 \text{ amps}} ]

Calculating this gives:

[ R = \frac{300}{0.025} = 12,000 \text{ ohms} ]

Therefore, the resistance of the lamp is 12,000 ohms. This calculation aligns with the laws of electrical engineering, demonstrating that the resistance increases as voltage increases or current decreases, according to the relationship defined by Ohm's Law.

This understanding is essential for anyone working in electrical fields, as it directly relates to how devices operate within safe electrical parameters. In this scenario, the conclusion that the resistance