Question

When two waves with same frequency and constant phase difference interfere,

• A. there is a gain of energy
  
• B. the energy is redistributed and the distribution changes with time
  
• C. the energy is redistributed, and the distribution remains constant in time.
  
• D. there is a loss of energy
  

Answer 1

The correct option is C the energy is redistributed, and the distribution remains constant in time.


As intensity is given by $I=\frac{\left(\frac{E}{t}\right)}{A}$
Where
$E=$ energy transported by the wave in
$t$ seconds
$A=$Area
And $I=I_1+I_2+2\sqrt{I_1.I_2}\cos \varphi$
As phase is constant, so the resultant intensity will not vary with time. So, we can say that when two waves of same frequency and constant phase difference interfere, the energy is redistributed, and distribution remains constant in time.
Final answer: $\left(d\right)$