更多"[单选题] The radio waves used for rada"的相关试题:
[单选题] The radar control used to reduce sea return at close ranges is the ______.
A.Gain control
B.Sensitivity time control
C.Fast time constant
D.Pulse length control
[单选题] ______ is not used in modern radar.
A.EBL
B.VRM
C.CRT
D.Grease pencil
[单选题] Which general statement concerning radar is FALSE ________.
A.Raising the antenna height increases the radar range
B.The ability of radar to detect objects is unaffected by weather conditions
C.Radar bearings are less accurate than radar ranges
D.Radar should be checked regularly during clear weather to ensure that it is operating properly
[单选题] Radar makes the most accurate determination of the ______.
A. direction of target
B. distance of target
C. size of a target
D. shape of a target
[判断题]等径弯头的曲率半径有1.5DN (通称长半径弯头)和 1.0DN(通称短半径弯头 Short Radius Elbow)两种。
A.正确
B.错误
[单选题] Which condition indicates that your radar needs maintenance ________.
A.Serrated range rings
B.Indirect echoes
C.Multiple echoes
D.Blind sector
[单选题] The radar control that reduces weak echoes out to a limited distance from the ship is the ______.
A.sensitivity time control(sea-clutter control)
B.receiver gain control
C.brilliance control
D.fast time constant(differentiator)
[单选题] In fog you observe your radar and determine that risk of collision exists with a vessel which is 2 miles off your port bow.You should ______.
A.stop your engines
B.sound the danger signal at two-minute intervals
C.hold course and speed until the other vessel is sighted
D.take avoiding action as soon as possible
[单选题] SWEEP INT on radar panel is the abbreviation of ______.
A.sweep introduction
B.sweep interest
C.sweep intention
D.sweep intensity
[单选题] Without doubt the radar is a highly important navigation aid. But duty officer shall aware that_____when using it.
A.Its range reading is more accurate than its bearing reading
B.A low-lying coastline with a long, flat beach will show up properly on the radar
C.Radar is only aimed at collision avoidance.
D.The use of radar is necessary only when visibility is restricted.
[单选题] A line of position derived by radar range from an identified point on a coast will be a(n)______.
A.Straight line
B.Arc
C.Parabola
D.Line parallel to the coast
[单选题] There is something wrong with our radar.All kinds of objects can't be clearly ______ within the definite range.
A.Shown
B.Expressed
C.Appeared
D.Displayed
[单选题] Radar makes it possible and much safer for us to sail ______.
A.In dense fog
B.In boisterous weather
C.In the open sea
D.In rivers
[单选题] What is the purpose of the radar reflector?
A. Making objects less visible
B. Making echoes weaker on the radar
C. Making large echoes smailer
D. Making small objects better visible
[单选题] What type of radar can activate a racon?
A. X-band radar
B. S-band radar
C. C-band radar
D. No radar can
[单选题] A radar display in which North is always at the top of the screen is a(n)______.
A. Unstabilized display
B. Stabilized display
C. Composition display
D. Relative display