Subelement G: Transmitters— Topic 55: SSB Transmitters
Question 3-55G6
Element 3 (GROL)What would be the voltage across a 50-ohm dummy load dissipating 1,200 watts?
Explanation
To determine the voltage across the dummy load, we use the fundamental electrical power formula that relates power (P), voltage (V), and resistance (R):
P = V²/R
To find the voltage (V), we rearrange the formula:
V = sqrt(P * R)
Given:
Power (P) = 1,200 watts
Resistance (R) = 50 ohms
Substitute the values into the formula:
V = sqrt(1,200 watts * 50 ohms)
V = sqrt(60,000)
V ≈ 244.95 volts
Rounding to the nearest whole number, the voltage is 245 volts.
Options B, C, and D are incorrect because they result from misapplying the power formula, such as incorrectly dividing instead of multiplying, or taking the square root of only part of the equation.
Related Questions
3-55G4 What is the approximate ratio of peak envelope power to average power during normal voice modulation peak in a single-sideband phone signal?3-55G5 What is the output peak envelope power from a transmitter as measured on an oscilloscope showing 200 volts peak-to-peak across a 50-ohm load resistor?3-56G1 How can intermodulation interference between two transmitters in close proximity often be reduced or eliminated?3-56G2 How can parasitic oscillations be eliminated in a power amplifier?3-56G3 What is the name of the condition that occurs when the signals of two transmitters in close proximity mix together in one or both of their final amplifiers, and unwanted signals at the sum and difference frequencies of the original transmissions are generated?