Tổng quan hệ thống GMDSS phục vụ TKCN. Năm 1979,Tổ chức Hàng Hải quốc tế (International Maritime Organization IMO) đã tổ chức hội nghị về vấn đề tìm kiếm và cứu nạn trên biển. ... Hệ thống mới được tự động hóa và sử dụng sóng vô tuyến trái đất và vệ tinh cho báo động cấp cứu và các thông tin theo sa
Trang 1Cau hoi 1 An Inmarsat-B installation uses a
B omnidirectional antenna
Cau hoi 2 As a safety precaution when working aloft near a transmitter antenna, ensure that the
A antenna insulators are clean and transmitter switched of
B transmitter switched of main fuses removed and connect antenna to earth
C transmitter is switched to the standby condition
D antenna is disconnected from the transmitter and main fuses removed
Cau hoi The safety loops on a long wire antenna
A allows the antenna to resonate on several diferent bands
B allows leakage of excess electromagnetic energy to earth
C support the antenna should increased tension cause the antenna to snap
D prevent electric shock to those working on deck
Cau hoi A safety precaution when working aloft near a transmitter antenna, is to
A disable the transmitter by removing the supply fuses
B lock the frequency on 2182 kHz with transmitter on low power and J3E
C ensure the transmitter is in the standby position only
D ensure the transmission mode is at H3E
Cau hoi The weak link is included on a safety loop to provide a
A low breaking strain in event of collision/grounding etc
B high breaking strain in event of collision/grounding etc
C high resistance path to electromagnetic energy
D low resistance path to electromagnetic energy
Cau hoi Insulators are included in an antenna system to provide a
A high resistance path to earth
B low resistance path to earth
C high breaking strain
D low breaking strain
Cau hoi Safety loops are fitted to wire transmitting antennas to
A isolate the antenna from earth
B prevents the antenna falling in case of increased tension
C act as an essential radiation element of the antenna
D prevent excessive electromagnetic leakage
Cau hoi A small omnidirectional antenna is used with
Trang 2D Inmarsat-C
Cau hoi A safety precaution when working aloft is to ensure the transmitter is safe by
A switching to the standby position and earthing the antenna
B switching to the standby position and selecting low power
C connect the antenna and switch to low power
D removing fuses and connecting the antenna to earth
Cau hoi Insulators on a ship’s antenna system are used to
A ofer a high resistance path to earth for electromagnetic energy
B prevent electric shock to those working on deck
C allow the antenna to be tuned to several frequencies
D ofer a low resistance path to earth for electromagnetic energy
Cau hoi An Inmarsat-C installation uses a
B parabolic dish antenna
C directional antenna
D omnidirectional antenna
Cau hoi A safety precaution when working aloft near a transmitter antenna, the antenna should be
switched to
A the transmitter on standby for testing
B earth as a safety precaution and remove transmitter supply fuses
C the transmitter (low power) and tuned to 2182 kHz
D the transmitter (low power) and tuned to 2187.5 kHz
Cau hoi Inmarsat Fleet 77 uses a
A directional antenna
C omnidirectional antenna
Cau hoi A safety precaution when working aloft is to
A lock the frequency on 2182 kHz with transmitter on low power and H3E
B ensure the transmission mode is at H3E
C ensure the transmitter is in the standby position only
D disable the transmitter by removing the supply fuses
Cau hoi The antenna used by an Inmarsat F 77 is
Cau hoi Inmarsat-C satellite equipment should be fitted with a
Trang 3A 1 to 1.5 metre dipole antenna
B unidirectional antenna within a protective dome
C 6 to 9 metre whip antenna
D omnidirectional antenna within a protective dome