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Producing Radio Waves at a Set Frequency
Some medical scanners produce radio waves at a specific frequency.
Explain how radio waves are produced at a specific frequency.
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Marking points
- 1 States that oscillations in a circuit, alternating current or oscillating electrons produce the radio waves.
- 2 States that the wave frequency equals the oscillation frequency.
Full-mark answer
An alternating current makes charges oscillate in the scanner's electrical circuit or aerial. The radio waves produced have the same frequency as those electrical oscillations.
Why this answer loses marks
The scanner chooses the frequency after the waves are emitted.
The frequency is set by the oscillating charge or alternating current that produces the waves.