4-22. An increase in refraction of a sonar sound beam has what effect, if any, on the range of the sonar? 1. Increases range only 2. Decreases range only 3. Increases range initially, then decreases it 4. None 4-23. Relative to propagation of sound in the ocean, which of the following statements is correct? 1. Speed is affected by salinity, pressure, and temperature 2. The higher the temperature, the lower the speed 3. Refraction increases effective range 4. Sound bends toward higher temperature 4-24. What is the density of seawater per cubic foot? 1. 6.24 lb 2. 6.40 lb 3. 62.40 lb 4. 64.00 lb 4-25. The effect of pressure on a  sound wave in the ocean tends to bend the wave in what direction? 1. Upward only 2. Downward only 3. Upward or downward IN ANSWERING QUESTIONS 4-26 through 4-28, SELECT  THE TEMPERATURE  CONDITION FROM COLUMN B THAT IS MOST CLOSELY RELATED TO EACH OF THE OPERATING CONDITIONS LISTED IN COLUMN A. NOT ALL RESPONSES IN COLUMN B ARE USED. A. OPERATING CONDITIONS 4-26. Unusual condition that results in upward refraction 4-21. Sound refracted downward because temperature decreases with depth 4-28. Even-temperature water throughout operating area B. TEMPERATURE CONDITIONS 1. Positive thermal gradient 2. Thermocline 3. Isothermal 4. Negative gradient IN ANSWERING QUESTION 4-29, REFER TO FIGURE 4-29. 4-30. 4-4 IN THE TEXTBOOK. The isothermal and cool water conditions shown in the figure have what effect, if any, on the sound beam?. 1. Causes the beam to bend upward only 2. Causes the beam to converge on the target 3. Causes the beam to split, bending part upward and part downward 4. None The definition for layer depth is the depth from the ocean 1. surface to the top of a  sharp positive gradient‘ 2. surface to the top of a  sharp negative gradient 3. bottom to the top of a  sharp positive gradient 4. bottom to the top of a  sharp negative gradient 26