Chapter 28, Problem 1CQ

To determine

The effect to their energy when two light waves interfere destructively.

Answer to Problem 1CQ

There is no energy at a point where destructive interference is complete. The total energy is in the system is unchanged because those regions with constructive interference have increased amount of energy.

Explanation of Solution

When two light waves interfere destructively, then the net energy of the resultant wave is less than the sum of the energies of the individual light waves while come to constructive interference, the net energy of the resultant wave is greater than the sum of the energies of the individual light waves.

The energy of the individual waves transferred from one place to another place where these waves behave constructively. Basically, the energy tends to zero at a place of destructive interference and at a place of constructive interference, the energy is greater than the sum of the energies of the individual light waves.

So, their energy is distributed again and again from destructive interference to the constructive interference when two light waves interfere destructively. Thus, there is no energy at a point where destructive interference is complete. The total energy is in the system is unchanged because those regions with constructive interference have increased amount of energy.

Conclusion:

Therefore, there is no energy at a point where destructive interference is complete. The total energy is in the system is unchanged because those regions with constructive interference have increased amount of energy.