Key Topic 4: Power, Pulse Width, PRR

Question 1

8-4A1: A pulse RADAR has a pulse repetition frequency (PRF) of 400 Hz, a pulse width of 1 microsecond, and a peak power of 100 kilowatts. The average power of the RADAR transmitter is:

A. 25 watts.
B. 40 watts.
C. 250 watts.
D. 400 watts.

Answer 1

B. 40 watts.

Question 2

8-4A2: A shipboard RADAR transmitter has a pulse repetition frequency (PRF) of 1,000 Hz, a pulse width of 0.5 microseconds, peak power of 150 kW, and a minimum range of 75 meters. Its duty cycle is:

A. 0.5
B. 0.05
C. 0.005
D. 0.0005

Answer 2

D. 0.0005

Question 3

8-4A3: A pulse RADAR transmits a 0.5 microsecond RF pulse with a peak power of 100 kilowatts every 1600 microseconds. This RADAR has:

A. An average power of 31.25 watts.
B. A PRF of 3,200.
C. A maximum range of 480 kilometers.
D. A duty cycle of 3.125 percent.

Answer 3

A. An average power of 31.25 watts.

Question 4

8-4A4: If a RADAR transmitter has a pulse repetition frequency (PRF) of 900 Hz, a pulse width of 0.5 microseconds, and a peak power of 15 kilowatts, what is its average power output?

A. 15 kilowatts.
B. 13.5 watts.
C. 6.75 watts.
D. 166.67 watts.

Answer 4

C. 6.75 watts.

Question 5

8-4A5: What is the average power if the RADAR set has a PRF of 1000 Hz, a pulse width of 1 microsecond, and a peak power rating of 100 kilowatts?

A. 10 watts.
B. 100 watts.
C. 1,000 watts.
D. None of these.

Answer 5

B. 100 watts.

Question 6

8-4A6: A search RADAR has a pulse width of 1.0 microsecond, a pulse repetition frequency (PRF) of 900 Hz, and an average power of 18 watts. The unit’s peak power is:

A. 200 kilowatts.
B. 180 kilowatts.
C. 20 kilowatts.
D. 2 kilowatts.

Answer 6

C. 20 kilowatts.