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

Characteristics of alternating currents — practice question

(a)[3]

In present-day communication systems, most data is sent in digital form instead of analogue form. Suggest three advantages of transmitting data in digital form.

(b(i).1)[1]

Suggest the effect on the quality of the recording of sampling at a high frequency rather than a lower frequency.

(b(i).2)[1]

Suggest the effect on the quality of the recording of using a long word length rather than a shorter word length.

(b(ii))[2]

A recording lasts for a total of $5$ minutes $40$ seconds. Calculate the number of bits produced during the recording. The music is sampled at $44.1\,\text{kHz}$ and each sample has a $16$-bit word.

(b(i)1)[1]

Suggest the effect on the quality of the recording of sampling at a high frequency rather than a lower frequency.

(b(i)2)[1]

Suggest the effect on the quality of the recording of using a long word length rather than a shorter word length.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Noise can be removed by filtering, or the signal can be regenerated

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