Explanation: In pulsed systems like radar, the duty cycle represents the fraction of time the transmitter is actively sending a pulse compared to the total cycle time. It's a key parameter in understanding average power output. The duty cycle is calculated by multiplying the pulse width (the duration of each pulse) by the pulse repetition frequency (PRF), which is the number of pulses transmitted per second. Duty Cycle = Pulse Width × PRF First, convert the pulse width from microseconds to seconds: 0.05 microseconds = 0.05 × 10$^{-6}$ seconds Now, calculate the duty cycle: Duty Cycle = (0.05 × 10$^{-6}$ s) × (2000 Hz) Duty Cycle = 100 × 10$^{-6}$ Duty Cycle = 0.0001 Therefore, the duty cycle is 0.0001. Options B, C, and D are incorrect calculations based on different magnitudes or unit errors.