DTVT2.Nhom3.Bai6 Radio Task : Television Task : Frequencies (tần số) Travels (đường truyền) Range (khoảng cách) Difficulties (khó khăn) Surface wave Low frequency (long waves) Along the ground About 1500km Absorbed by the ground Task : Sky wave Space wave Frequencies (tần số) below 300MHz VHF, UHF Skywards and returned to earth by the ionosphere Travels (đường truyền) line of sight transmission Range (khoảng cách) Hàng nghìn km 150km Difficulties (khó khăn) attenuated by refraction hills, buildings, or trees Task : A Transmitting aerial E Surfaca wave D Space wave C Sky wave B Receiving aerial Task : When the switch is closed, current flows through the primary of the transformer On being reflected, the radar signal trikes a plane When a cell discharges quickly, it may become hot On following your instructions, the TV receives signal from the remote control On being compared with the transmitted signal, the radar receiver receives the reflected signal When choosing a course in electronics, you think carefully about your future On being deflected, microwave signals strike a high building When making a recording, you should ensure the recording levels are satisfactory On triggering an audible warning, the alarm detects an intruder 10 When the remote control button is pressed, the television set changes channel Task : Verb Absorb Attenuate Communicate Conduct Induct Modulate Reflect Resist Task 9: AF- Audio frequency RF- Radio frequency AM- Amplitude modulated FM- Frequency modulated Task 10: a b c d Task 11: Noun (component) Absorber Attenuator Communicator Conductor Inductor Modulator Reflector Resistor RF carrier AF signal AM carrier FM carrier Noun (property) Absorption Attenuation Communication Conductivity Induction Modulation Reflection Resistance