Physics 9702 · AS & A Level · Characteristics of alternating currents
Characteristics of alternating currents — practice question
Long-distance radio communication using ionospheric reflection has, to a large extent, been superseded by satellite communication.
(a)[4]
State and explain two reasons why this change has taken place.
(b)[2]
The radio link between a geostationary satellite and Earth may suffer attenuation of as much as $190\,\text{dB}$. Suggest why this means the uplink and downlink frequencies must be different.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Communication was unreliable because the ionospheric layers kept changing” …