The \"normal modes\" of a cavity are the set of standing waves which have a cert

Question

The "normal modes" of a cavity are the set of standing waves which have a certain relation between the wavelength and the length of the cavity. Consider a one dimensional cavity of length L = 10 cm formed in the x direction between two perfect conductor plates that are placed at x = 0 and x = L, respectively. Answer the following questions (take the speed of light as c = 3.0x10s m/s): Calculate the smallest possible frequency of the standing wave that can exist in this cavity. Suppose that the second normal mode is present inside the cavity. At a particular time, the magnetic field inside the cavity is known to be zero everywhere. After how many seconds will the electric field be equal to zero everywhere for the first time? Suppose that only the second normal mode is present inside the cavity. Plot the amplitude of the magnetic field component of the standing wave as function of x at a time when the electric field is equal to zero everywhere inside the cavity.

Explanation / Answer

a)f = v/(2*L) = 3*10^8/(2*0.1) = 1.5*10^9 HZ

b)f2 = 3*10^9 HZ

T = 1/f2 = 3.33*10^-10 s

after T/2 seconds.....so after 1.67*10^-10 s


c) Y = A*sin(kx-wt)

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.