🔍 Key Concepts

• PPI radar display and what a range ring represents • Relationship between range ring spacing (in nautical miles), pulse repetition frequency (PRF), and the time it takes a pulse to travel to that range and back • Speed of radio waves (radar pulses) is approximately the speed of light

💭 Think About

• First, think about how long it takes a radar pulse to travel out to 10 NM and back. What time does that correspond to? • Once you have the round‑trip time for 10 NM, ask: if one cycle of the oscillator corresponds to that time, what frequency in kHz does that equal? • Compare your calculated frequency to the answer choices and see which one most closely matches your computed value.

✅ Before You Answer

• Convert nautical miles to meters correctly before using the speed of light. Double‑check this conversion. • Remember that frequency = 1 / period, and express the result in kilohertz (kHz), not hertz. • Verify that you used the round-trip distance (out and back) for the radar pulse, not just the one‑way distance.