Final answer:
To increase the energy carried by an electromagnetic wave, one can either increase the amplitude (E) while keeping frequency (w) constant, or increase the frequency while keeping amplitude constant. Both actions will result in increased energy, making option C the correct choice. Option C. Both of the above will increase the energy is the correct answer.
Explanation:
When considering the energy carried by an electromagnetic wave, several factors are involved, including the amplitude (E) of the electric and magnetic fields and the frequency (w) of the wave. According to the principles of electromagnetism, the energy conveyed by an electromagnetic wave is directly proportional to the amplitude squared and the frequency of the wave. Increasing the amplitude of the wave (option A) while keeping the frequency constant will result in a proportional increase in the wave's energy because energy is proportional to the amplitude squared, as exemplified in figures 24.24 and 16.10. On the other hand, increasing the frequency (option B) also increases the energy, as energy and frequency are directly related, where higher frequency photons carry more energy than lower frequency ones.
Based on this understanding, both an increase in amplitude, keeping frequency constant, and an increase in frequency, keeping amplitude constant, will lead to an increase in the energy carried by an electromagnetic wave. Therefore, the correct option for the student's question is option C. Both of the above will increase the energy.