Explanation: The average power output of a pulsed transmitter, like a RADAR, is determined by its peak power multiplied by its duty cycle. The duty cycle (DC) is the fraction of time the transmitter is actually emitting a pulse. It's calculated as: DC = Pulse Width (τ) × Pulse Repetition Frequency (PRF) Given: * PRF = 900 Hz * Pulse Width (τ) = 0.5 microseconds = 0.5 × 10⁻⁶ seconds * Peak Power (P_peak) = 15 kilowatts = 15,000 watts First, calculate the duty cycle: DC = (0.5 × 10⁻⁶ s) × 900 Hz = 0.00045 Next, calculate the average power (P_avg): P_avg = P_peak × DC P_avg = 15,000 watts × 0.00045 = 6.75 watts Option A is incorrect because 15 kilowatts is the *peak* power, not the average power. For a pulsed system, average power is always significantly lower than peak power because the transmitter is off for most of the time. Options B and D are incorrect based on the calculation.