question_answer

The displacement y of a particle in a medium can be expressed as \[y={{10}^{-6}}\sin \left( 100t+20x+\frac{\pi }{4} \right)m\], where t is in second and \[x\]in metre. The speed of the wave is                                           [AIEEE 2004]

A) \[2000\,m/s\]                 

B) \[5\,\,m/s\]

C) \[20\,\,m/s\]                   

D) \[5\pi \,\,m/s\]

Correct Answer: B

Solution :

[b] As given

...(i)

Comparing it with

(ii)

We find,