Aviation Electronics Technician 1 - Historic Naval Ships Association

ASSIGNMENT 4Textbook Assignment: “Antisubmarine Warfare,” chapter 4, pages 4-1 through 4-17.4-1. Sonar is an acronym derived fromusing the first letters of whatterms?1. Sound, Navy, return2. Sound, naval, rate3. Sound, navigation, ranging4. Sound, NAVAIR, range4-2. Echo-ranging sonar relies on thereception of an echo to determinewhat information about a target?1. Range only2. Bearing only3. Range and bearing only4. Range, bearing, and frequency4-3. What type of sonar does NOTtransmit sound, but functions byreceiving sound from the target?1. Active2. Passive3. Reverberation4. Return4-4. A high-pressure area occurs in thewater next to a hydrophone eachtime the hydrophone moves in whatdirection?1. Inward only2. Outward only3. Upward only4. Downward only4-5. The high-pressure area in a soundwave is known as a4-7.4-8.4-9.4-10.4-11.The wavelength of a sound wave isequal to the distance between twosuccessive1. rarefactions only2. compressions only3. rarefactions or compressions4. diaphragm vibrationsThe frequency of a sound wave isdefined as the number of which ofthe following item that occurs in1 second?1. Wavelengths2. Compressions3. Rarefactions4. DepressionsAbsorption of sound waves in theocean is least during which of thefollowing water conditions?1. White-capped waves2. Smooth sea surface3. Ship’s wake4. RiptidesAbsorption of sound waves in theocean is greatest during which ofthe following transmissions?1. Low frequency2. High frequency3. Low amplitude4. High amplitudeForeign matter in seawater includeswhich of the following items?4-6.1. depression2. rarefaction3. compression4. wavelengthThe low-pressurewave is known as1. depression2. rarefaction3. compression4. wavelengtharea in a sounda1. Silt and animal life only2. Animal life and seaweed only3. Silt and seaweed only4. Silt, animal life, seaweed, andair bubbles23