Physics 9702 · AS & A Level · Characteristics of alternating currents

Characteristics of alternating currents — practice question

(a(i))[1]

Information can be transferred through different communication channels. State one application, for each case, in which information is transferred by microwaves.

(a(ii))[1]

Information can be transferred through different communication channels. State one application, for each case, in which information is transferred by coaxial cables.

(a(iii))[1]

Information can be transferred through different communication channels. State one application, for each case, in which information is transferred by wire pairs.

(b(i))[2]

A station on Earth sends a signal with initial power $3.1\,\text{kW}$ to a geostationary satellite. The attenuation of the signal received by the satellite is $190\,\text{dB}$. Calculate the power of the signal received by the satellite.

(b(ii))[3]

Referring to your answer in (i), state and explain what changes are made to the signal before it is transmitted back to Earth.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: a communication-system example (for example, satellite or mobile phone)

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