# Is it necessary for coherent waves to have same frequency?

• khurram usman
In summary, the conversation discusses the concept of coherent waves and whether it is necessary for them to have the same frequency. The speaker argues that while constant phase difference is important, the frequencies can be different as long as they are whole multiples of each other. The topic of amplitude is also briefly mentioned.
khurram usman
i mean what more are coherent waves except 'having constant phase differnce'?i mean it is nt necessay for them to be in phase .they can be out of phase but must have a cnsstant phase diff. say pie/2 radian
so what i mean to ask is that is it necessary for coherent waves to be of same frequency. can't they be of differnt frewuency? bcoz even if they are of differnt frequency like say one is a multiple of other like twice of it even then the condition of CONSTANT PHASE DIFFERENCE be satisfied?
so shortly is it necessary that the coherent waves have same frequency or can they have frequencies dat are whole multiples of each other(256 , 512)?
also what abt their amplitude?

See here: http://en.wikipedia.org/wiki/Coherence_(physics )

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## 1. What are coherent waves?

Coherent waves are waves that have a constant phase difference and the same frequency. This means that the peaks and troughs of the waves are aligned and they vibrate at the same rate.

## 2. Why is it important for coherent waves to have the same frequency?

Having the same frequency allows the waves to maintain a constant phase difference, which is necessary for constructive interference and the formation of a stable interference pattern.

## 3. Can coherent waves have different amplitudes?

Yes, coherent waves can have different amplitudes. The amplitude of a wave refers to its maximum displacement from the equilibrium position, and it does not affect the frequency or phase difference of the wave.

## 4. What happens when coherent waves with different frequencies are combined?

When coherent waves with different frequencies are combined, they will no longer maintain a constant phase difference. This will result in destructive interference and the formation of an unstable interference pattern.

## 5. How are coherent waves used in practical applications?

Coherent waves are used in various applications such as lasers, holography, and radio communication. They allow for precise and controlled interference patterns, which can be used for measurements, data transmission, and image formation.

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