| English | Frequency |
|---|---|
| Bahasa Melayu | Frekuensi |
| 中文 | 频率 |
Definition
The number of complete oscillations or waves produced in one second; measured in hertz (Hz).
In exam terms
Frequency is the number of complete oscillations or waves produced in one second. Its symbol is f and its unit is the hertz (Hz), where 1 Hz = 1 oscillation per second (s⁻¹).
Frequency is the reciprocal of the period: f = 1 ÷ T, with T in seconds. For example, if one complete wave takes 0.02 s, then f = 1 ÷ 0.02 s = 50 Hz.
Frequency also appears in the wave equation v = fλ. A source of high frequency produces more waves each second, so for a fixed speed the wavelength is shorter.
Do not confuse it with period
Frequency counts waves per second (Hz), while period is the time for one wave (s). They are reciprocals: f = 1 ÷ T. A frequent slip is quoting a period in hertz or a frequency in seconds, which loses marks.
In Paper 2 you may be asked to state what frequency means or to calculate it using f = 1 ÷ T or f = v ÷ λ. Give the answer in hertz, and remember that when a wave crosses into a new medium during refraction the frequency stays the same.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)