Ham Radio General Class Practice Test

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Boost your ham radio knowledge with our engaging questions and detailed explanations. Prepare effectively with our diverse study resources. Ready to ace the General Class exam?

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

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How many watts of electrical power are used if 400 VDC is supplied to an 800-ohm load?

0.5 watts
200 watts
400 watts
3200 watts

The correct answer is: 200 watts

To determine the power used by an electrical load, we can use the formula that relates voltage (V), current (I), and resistance (R): Power (P) can be calculated using the formula: \[ P = \frac{V^2}{R} \] In this scenario, we are given a voltage of 400 VDC and a resistance of 800 ohms. Plugging these values into the formula provides the calculation: \[ P = \frac{(400 \, \text{V})^2}{800 \, \Omega} \] \[ P = \frac{160000 \, \text{V}^2}{800 \, \Omega} \] \[ P = 200 \, \text{W} \] This calculation shows that the power consumed by the load is 200 watts. Understanding power calculations is essential in ham radio and electrical engineering, as it helps ensure that equipment operates efficiently and within its specified power ratings. Here, the other options do not align with the calculated power based on the given voltage and resistance; hence, they do not correctly represent the situation.