ASVAB (Armed Services Vocational Aptitude Battery)Paragraph Comprehension (PC)Medium
Read the following passage: "The development of radar technology during World War II was a pivotal moment in military history. Initially conceived for detecting enemy aircraft and ships, its capabilities quickly expanded to include navigation and weather forecasting. Early radar systems operated by emitting radio waves and detecting the reflections, or 'echoes,' off distant objects. The time it took for an echo to return, combined with the direction from which it came, allowed operators to determine an object's range and bearing. This innovation dramatically altered battlefield awareness and defense strategies, leading to significant advantages for the Allied forces." Which of the following can be inferred about early radar systems?
- AThey primarily used sound waves to detect objects.
- BThey were only effective in clear weather conditions.
- CThey provided information about an object's location.
- DThey were too complex for widespread military use.
Show answer & explanationAnswer & explanation
Correct answer: C. They provided information about an object's location.
The passage states that 'The time it took for an echo to return, combined with the direction from which it came, allowed operators to determine an object's range and bearing.' Range and bearing are components of an object's location.
Why the other options are wrong
- A. The passage clearly states radar used 'radio waves,' not sound waves.
- B. The passage mentions weather forecasting as an expanded capability, implying it could operate in various weather, and does not state it was limited to clear conditions for detection.
- D. The passage indicates widespread use, stating it 'dramatically altered battlefield awareness and defense strategies.'
Radar Principles
Radar (Radio Detection and Ranging) uses radio waves to detect objects and determine their range, angle, or velocity.
- Emits radio waves and detects echoes.
- Time delay of echo determines range.
- Direction of echo determines bearing.
Memory trick: Radar's Radio Waves Reveal Range and Bearing.