Ham Amateur Radio Technician Practice Exam 2026 – The Complete All-in-One Guide to Exam Success

To find the RMS voltage across a 50-ohm dummy load that is dissipating 1200 watts, we can use the formula that relates power, voltage, and resistance:

Power (P) is given by the formula:

\[ P = \frac{V^2}{R} \]

Where:

- \( P \) is the power in watts,

- \( V \) is the RMS voltage in volts,

- \( R \) is the resistance in ohms.

In this case, we have:

- \( P = 1200 \) watts,

- \( R = 50 \) ohms.

Rearranging the formula to solve for \( V \) gives us:

\[ V = \sqrt{P \times R} \]

Now we can substitute the known values:

\[ V = \sqrt{1200 \, \text{W} \times 50 \, \Omega} \]

Calculating the multiplication gives:

\[ V = \sqrt{60000} \]

Calculating the square root of 60000 results in:

\[ V \approx 244.94 \, \text{volts} \]

Rounding this to a more typical value gives us approximately 245 volts.