Frequency is a measure of repetition of a quantity over a specific time interval. S (Second) cannot be used for representing frequency. Hz or hertz is the SI unit representation of frequency, other units are Beats per minute (BPM) and Rotation per minute (RPM).

Audible frequency range means, frequency of the sound signal that can hear by humans. Audible frequency range of human is recognized as between 20Hz and 20 KHz.

Frequency is the ratio of angular frequency and 2Ï€. Here angular frequency is 4Ï€.

Angular frequency is the product of the frequency of a system and 2Ï€. Frequency is represented in Hertz and angular frequency is represented in rad/sec.

All waves in electromagnetic spectrum has the same speed in vacuum and their speed will be equal to speed of light c. Hence wavelength can be represented as inversely proportional to frequency.

Speed of light is independent on any factors only in vacuum, in a dispersive medium it may vary according to wavelength of light. Hence the inverse proportionality may not be always correct here.

In vacuum product of wavelength and frequency of light can be equated to speed of light, that is wavelength and frequency are inversely proportional.

Stroboscope is a frequency measuring instrument which uses another reference signal with a known frequency. Voltmeter is used for measuring voltage and Ammeter is used for measuring current.

Colors of rainbow lies in the frequency range 4 – 8×1014Hz, in which 4×1014Hz represents frequency of red light.

Frequency is the number of occurrence of an event in a given time interval. That is for 35 events in 7 seconds frequency is 35÷7=5Hz.