# Radar MCQ (Multiple Choice Questions)

1. What does RADAR stand for?
a) Rapid Deployment and Recognition
c) Radar is not an acronym
d) Remote Analysis and Display of Aerial Reconnaissance

Explanation: RADAR stands for Radio Detection and Ranging. It is a technology that uses radio waves to detect and determine the range, angle, or velocity of objects.

2. What is the purpose of a radar jammer?
c) Disrupt or deceive radar signals
d) Amplify target echoes

Explanation: A radar jammer is designed to disrupt or deceive radar signals, making it difficult for radar systems to accurately detect and track targets.

3. In order to obtain the radar receiver output, which filter is used to maximize the output signal-to-noise ratio?
a) Matched filter
b) High pass filter
c) Band reject filter
d) Doppler filter

Explanation: In order to increase the output SNR ratio, matched filter is the perfect choice which operates in the presence of additive stochastic noise. To put it simply, it maximizes the ratio of output peak power to mean noise power in frequency response.

4. Why is it necessary to maximize the signal to noise ratio at the output of IF amplifier?
a) To maintain uniformity of signal
b) To reduce the noise components
c) To maximize max power transfer
d) To maximize the video output

Explanation: The signal to noise ratio in the radar range equation is present at the output of the IF amplifier because maximizing the SNR at the output of the IF is equivalent to the video output where the threshold decision is made.

5. Why are pulse Doppler radars operated with a pulse repetition frequency (PRF)?
a) To reduce the existence of probability distribution function
b) To generate high duty cycle
c) To obtain range ambiguities
d) To generate false alarm

Explanation: Pulse Doppler radar are operated with a pulse repetition frequency since due to that range ambiguities can be generated in order to know if the transmitted pulses have exceeded the distance. Doppler radar makes use of range ambiguities in order to detect targets even in the presence of clutter.

6. Why was the MTI processor preceded by a large dynamic range receiver?
a) Avoid reduction in improvement factor
b) Avoid clutter noise
c) Avoid any range ambiguities
d) Avoid Doppler frequency

Explanation: One of the biggest limitation of an MTI processor is that it has a poor reduction factor because of limiting which is much better in a large dynamic range receiver. There when the output was transmitted to I and Q phase detectors, the analog to digital converters helped in changing the analog signals to digital words.

7. Which out of the following is not a limitation to MTI performance?
a) Limiting
b) Resistance
c) Internal fluctuation clutter
d) Antenna scanning modulation

Explanation: Resistance is not a limitation to MTI performance. The limitation of MTI performance causes the clutter spectrum to widen. More clutter energy is then passed by the Doppler filter, which lowers the improvement factor.

8. Which electromagnetic wave is commonly used in radar systems?
a) Microwaves
b) Ultraviolet
c) Infrared

Explanation: Radar systems commonly use radio waves, specifically microwaves, for their ability to travel long distances and penetrate various weather conditions.

9. What is the significant difference between MTI and pulse Doppler radar (PDR)?
a) MTI receives more clutter than PDR
b) PDR uses filter bank while MTI used analog delay line canceller
c) PDR receives more clutter than MTI
d) MTI uses high power whereas PDR uses low power amplifier

Explanation: The significant difference between MTI and pulse Doppler radar is that PDR generally receives much more clutter than an MTI radar because of the fold over in a range of clutter echoes when ambiguous PRFs are employed, so that the pulse Doppler radar requires a much greater improvement factor than does an MTI radar of comparable performance.

10. What is the purpose of Doppler filter in a simple CW Doppler radar?
a) Removes Doppler frequency from the signal
b) Passes signals with Doppler frequency within its pass band
c) Increases the strength of the clutter signal
d) Increases the strength of the Doppler frequency

Explanation: The Doppler filter passes signals with a Doppler frequency fd located within its pass band, but the sign of the Doppler is lost along with the direction of the target motion. It has a lower frequency cutoff to remove from the receiver output the transmitter leakage signal and clutter echoes.

11. Which of the following is a four port device that provides at its two output ports the sum and difference of the signals that are at its two input ports?
a) Local oscillator
b) Amplitude detector
c) Hybrid junction
d) Phase sensitive detector

Explanation: The hybrid junction is a four port device that provides at its two output ports the sum and difference of the signals that are at its two input ports. For monopulse radar, they are usually constructed from waveguide, but they can also be in coax or stripline. The hybrid junction is known as the magic-T consists of an E-plane T-junction and an H-plane T-junction.

12. What is the method for broadbanding of a multi-cavity klystron?
a) Collector tuning
b) Power tuning
c) Peak tuning
d) Stagger tuning

Explanation: Broadbanding of a multi-cavity klystron can be accomplished by stagger tuning the cavities, similar to the method for broadbanding a conventional multistage IF amplifier. Stagger tuning a klystron is not precisely analogous to stagger tuning an IF amplifier because of interactions among the cavities that can cause the tuning of one cavity to affect the tuning of the others.

13. Which radar parameter determines the ability to separate two closely spaced targets?
a) Pulse repetition frequency
b) Pulse width
c) Pulse compression
d) Pulse duration

Explanation: Pulse compression enhances the ability to separate closely spaced targets by using coded pulses.

14. What is the full form of RAMP?

Explanation: The RAMP (Radar Modernization Project) radar system was an L-band (1250 to 1350 MHz) air traffic control Primary Surveillance Radar (PSR) located at major airports across Canada. It was developed by Raytheon Canada and had a range of 80 nmi and an altitude coverage of 23,000 ft against a 2 m2 aircraft target with 80 percent probability of detection.

15. What does MTI stand for in radar technology?
a) Magnetic Target Interceptor
b) Mobile Tracking Instrument
c) Moving Target Indicator
d) Multi-Target Identification

Explanation: MTI, or Moving Target Indicator, is a radar system feature that helps distinguish between stationary and moving targets.

16. Which one out of the following is a UHF radar developed by Raytheon that was the first all solid state active aperture electronically steered phased array radar?
a) RP-21 Sapfir
b) AN/FPS-115

Explanation: AN/FPS-115 is a UHF radar developed by Raytheon that was the first all solid state active aperture electronically steered phased array radar. Its function was to detect and warn of sea-launched ballistic missiles fired at the United States. It operated from 420 to 450 MHz with a peak power of 600 kW and an average power of 150 kW, which corresponds to a duty cycle of 0.25.

17. What is the primary purpose of a monopulse radar system?
a) Simultaneous multiple target tracking
b) High-resolution imaging
c) Long-range detection
d) Low probability of intercept

Explanation: Monopulse radar systems are known for their ability to simultaneously track multiple targets with high precision.

## Chapterwise Multiple Choice Questions on Radar

Our MCQs focus on all topics of the Radar subject, covering all topics. This will help you to prepare for exams, contests, online tests, quizzes, viva-voce, interviews, and certifications. You can practice these MCQs chapter by chapter starting from the 1st chapter or you can jump to any chapter of your choice.

## 1. MCQ on Radar Equation

The section contains multiple choice questions and answers on essential radar concepts, including the radar equation, receiver noise, SNR ratio, probability density functions, probabilities of detection and false alarm, integration of radar pulses, types of targets, radar cross-section fluctuations, pulse repetition frequency, antenna parameters, and system losses.

## 2. MTI and Pulse Doppler Radar

The section covers questions and answers on Doppler radar, MTI radar, delay line cancelers, staggered pulse repetition frequency, Doppler filter banks, digital MTI processing, moving target detector, limitations to MTI performance, and pulse Doppler radar.

The section contains MCQs on tracking radar, limitations to tracking accuracy, and low-angle tracking.

The section contains multiple choice questions and answers on radar transmitters, solid-state RF power sources, and magnetron and crossed field amplifiers.

If you would like to learn "Radar" thoroughly, you should attempt to work on the complete set of 1000+ MCQs - multiple choice questions and answers mentioned above. It will immensely help anyone trying to crack an exam or an interview.

Wish you the best in your endeavor to learn and master Radar!

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