The radar component that produces the synchronizing signal and triggers the indicator sweep is which of the following?（）.

单项选择题The transmission time duration of a single pulse of radio-frequency energy is a function of the（）.

A.persistence
B.pulse repetition rate
C.pulse length
D.resolution

单项选择题You are using a radar in which your own ship is shown at the center，and the heading flash always points to 0°. If bearings are measured in relation to the flash，what type of bearings are produced?（）.

A.Relative
B.TRUE
C.Compass
D.Magnetic

单项选择题Compass deviation is caused by（）.

A.magnetism from the earth's magnetic field
B.misalignment of the compass
C.magnetism within the vessel
D.a dirty compass housing

单项选择题Compass error is equal to the（）.

A.deviation minus variation
B.variation plus compass course
C.combined variation and deviation
D.difference between true and magnetic heading

单项选择题Deviation in a compass is caused by the（）.

A.vessel's geographic position
B.vessel's heading
C.earth's magnetic field
D.influence of the magnetic materials of the vessel