Question 1
Describe the three characteriscs of a sine wave. 描述正弦波的三个特性。
Answer: phase, amplitude, frequency
Question 20 Single-Choice
A periodic signal complete one cycle in 0.001 s. What is the frequency? 一个周期函数在0.001秒内完成一个周期。问它的频率是多少？
A. 1 Hz B. 100 Hz C. 1 KHz D. 1 MHz
Answer:C.1KHz
Question 79 Exercise
The attenuation of a signal is -10 dB. What is the final signal power if it was originally 5 W? 已知信号的衰减是-10分贝。如果信号原来是5瓦，求最后的信号功率。
Answer:
P0=Pi*A
A = -10dB=0.1
P0=0.5W
