Test for chapter 14%2615

Test for chapter 14 and 15

1. There two parallel conducting plates at y = 0 and y = 磨具制造b. Between the two plates, if the electric field is E=i Ex(y) ei(kz-t), the function of Ex(y) must be in the form of ____.

A) 自动涂装线E0 sin(ny/b) B) E0 cos(ny/b) C) E0 D) E0 sinh(ny/b)

2. Between two parallel conducting plates, if the electric field is E板栗割口机=i Ex(z) ei(ky-t), the function of the magnetic field must be in the form of

A) B = (j By+z Bz) ei(ky-t) B) B = j By ei(ky-t)软件自动化测试技术

C) B = (j By+i Bz) ei(ky-t) D) B = i Bx ei(ky-t)

3. In a rectangular wave guide with cross-section a = 4 cm and b = 6 cm, the lowest cut-off frequency is ____.

A) 5 GHz B) 7.5 GHz C) 15 GHz D) 1.5 GHz

4. In a rectangular wave guide with cross-section a = 4 cm and b = 6 cm, the frequency of the input wave is 8.5 GHz. With what kinds of TE modes the wave can propagate?

A) (0, 1), (1, 0) B) (0, 1), (1, 0), (1, 1) C) (0, 1) D) (1, 0)

5. In a rectangular wave guide with cross-section a = 10 cm and b = 6 cm, the group velocity of a wave of frequency 10 GHz in the TE(1, 0) mode is _____.

A) 0.95 c* B) 4.17 c C) 0.24 c D) c

6. The retarded potential tz15V(x, t) in (15.19) is the solution of the equation

A) 2V+(2V)/( c2t2) = /0 B) 2V = /0

C) A = (V)/( c2t) D) E = /0

7. For an electric dipole p = Q0d eitz, where z is the unit vector of the z axis, Jd3x’ = _____.

A) iQ0 d eitz B) ip C) iQ0 d eit D) Q0 d eitz

8. For an electric dipole p = Q0d pds虹吸排水系统eitz, where z is the unit vector of the z axis, the potential (15.34) is obtained under the approximations of _____.

A) d << r, and d << B) d << r C) d << D) p it

9) If the vector potential A of the radiation of an electric dipole has been obtained, with what equation can you get the scalar potential V?