Wave Mechanics Question 625
Question: A plane progressive simple harmonic sound wave of angular frequency $ 680rad/s $ moves with speed 340 m/s in the direction which makes equal angle with each x, y and z-axis. The phase difference ( $ {\phi _{1}}-{\phi _{2}} $ ) between the oscillations of the particle in the medium located at the positions $ (\sqrt{3,}\sqrt{3,}\sqrt{3}) $ and $ (2\sqrt{3,},2\sqrt{3,},2\sqrt{3}) $ is (assume $ \cos \theta >0 $ )
Options:
A) 2 radian
B) 3 radian
C) 4 radian
D) 6 radian
Show Answer
Answer:
Correct Answer: D
Solution:
[d] $ y(\overset{\to }{\mathop{r}},,t)=A,\sin (\omega t-\overset{\to }{\mathop{k}},.\overset{\to }{\mathop{r}},) $
$ \hat{k}=\frac{2\pi }{\lambda }(\cos \alpha \hat{i}+\cos \beta \hat{j}+\cos \gamma \hat{k})=\frac{k}{\sqrt{3}}(\hat{i}+\hat{j}+\hat{k}) $
$ {\phi _{1}}-{\phi _{2}}=2(3)=6,rad. $
BETA
