38. A 50-Ω transmission line is connected to a load of impedance Z_L = 35 + j80Ω. Find the position d and length  of a short-circuited stub required for impedance matching, as shown in the Fig. 4.

(A)d= 0.016λ,= 0.076
(B)
(C)d= 0.266λ,= 0.0761；
(D)
(E) It is impossible to match the load using the single-stub matching circuit.

34. If the load is a scries resistor R = Zo and inductor L, which statement is WRONG? (A) The current at the load should be continuous versus t, due to the presence of L. (B) The inductor is initially open, hence the voltage at the load will be Vo at  t =T+. (C) The reflected wave will be of positive voltage for t> T. (D)The voltage at the load will be zero as t tends to infinity.

35. If the load is a pure capacitor C, which statement is WRONG? (A) The voltage at the load should be continuous versus t, due to the presence of C. (B) The capacitor is initially short, hence the voltage at the load will be O at t=T+. (C) The reflected wave will be of positive voltage for t much larger than T. (D)The voltage at the load will be zero as t tends to infinity.

36. If the load is a shunt connection of capacitor C and resistor R =Zo, which statement is WRONG? (A)The voltage at the load should be continuous versus t, due to the presence of C. (B) The capacitor is initially short, hence the voltage at the load will be zero at t=T. (C) The reflected wave will be of positive voltage for t much larger than T. (D) The voltage at the load will be Vo/2 as t tends to infinity.

37. Design a transmission line of characteristic impedance Zo and length , as shown in the Fig. 3, to match a resistive load RI = 300 Ω to a lossless transmission line of characteristic impedance Zo = 75 Ω (A)Z1= 150Ω,=λ/8 (B) Z1= 187.5Ω,=λ/8 (C) Z1= 150Ω,=λ/4 (D) Z1= 187.5Ω,=λ/4 (E)Z1= 150Ω, =λ/2

39. Figure 5 shows a power divider of power ratio PL1/PL2 =1, where PL1 and PL2 are the power delivered to the loads Rei and Riz, respectively. The loads have resistance RiI = 750 and RL2 = 300 , and the characteristic impedance of the transmission line is Z0 = 50 Ω . Find the characteristic impedances Z1 and Z2 of the quarter-wavelength transmission linesso that the impedance is matched from the source. (A) Z1=61.2Ω,Z2 = 122.5Q； (B)Z1= 122.5Ω, Z2=61.2Ω； (C)Z1=86.62Ω,Z2=173.2Ω； (D) Z1= 173.2Ω,Z2 =86.6Ω； (E) It is impossible to match the loads by using the quarter-wavelength transformers.

40. A 50-Ω transmission line is connected to a load of impedance ZL = 35 + j80Ω. Design a double-stub matching circuit shown in the Fig. 6. Short-circuited stubs are used and the position of the second stub is d =λ/8. (A) (B)(C)(D)(E) It is impossible to match the load using the double-stub matching circuit.

1. 「對權貴逢迎巴結，是小人的行徑，為正人君子所不□。」缺空處 宜填入： (A)禠(B)齒(C)恥(D)侈。

2. 下列成語，意思相近的是： (A)「異口同聲」與「眾說紛紜」(B)「未雨綢繆」與「亡羊補 牢」(C)「期期艾艾」與「口若懸河」(D)「反掌折枝」與「探 囊取物」。

3. 「這位青年作家由於才思敏捷，得到王老作家的激賞，兩人於是結 為□□□□。」缺空處宜填入： (A)刎頸之交(B)八拜之交(C)忘年之交(D)管鮑之交。

4. 「創業的人都會自然而然的想到上天」。與此句意旨相同的是： (A)人在做，天在看(B)一根草，一點露，天無絕人之路(C)食 碗內，說碗外(D)食米飯拜田頭。