MOOC 信号与系统（英文）(北京交通大学)1206630834 最新慕课完整章节测试答案
CHAPTER I - Course Overview
文章目录
Test on Chapter 1
1、单选题：
Which of the below deterministic signals is a continuous-time energy signal: ( ).
选项：
A: 
B: 
C: 
D: 
答案: 【 】
2、单选题：
Given a periodic continuous-time signal 
, what is the signal's period 
and the average power 
? ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
3、单选题：
Given the below relationships between the voltage and the current, please pick the system that is time-variant ( ).
选项：
A: 
B: 
C: 
D: 
答案: 【 】
4、单选题：
Below are four discrete-time system and the relationship between the input, 
, the output, 
, and the initial state, 
is given for each of the systems. Which is not a linear system? ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
5、单选题：
Given the relationship between the input 
, the output 
, and the initial state 
, which of the systems is a linear system? ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
6、单选题：
Which of the below system is a time-invariant system? Given that 
or 
is the input of the system and 
or 
is the output. ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
7、单选题：
Given the difference equation of a discrete-time system is 
, then the system is ( ).
选项：
A: Causal and linear time-invariant.
B: Causal and linear time-varient.
C: Non-causal and linear time-invariant.
D: Non-causal and linear time-variant.
答案: 【 Causal and linear time-invariant.】
8、单选题：
For a linear continuous-time system, when the initial state is 
and the input signal is 
, the output is 
, 
; when the initial state is 
and the input signal is , the output is 
, 
. Then, what is the output when the initial state is and the input signal is 
? ( )
选项：
A: 
B: 
, 
C: 
, 
D: 
, 
答案: 【 , 】
CHAPTER II - Signal Analysis in the Time Domain
Test on Chapter 2
1、单选题：
A sinusoidal signal 
can be represented by using imaginary exponential signal 
as ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
2、单选题：
Which one of the below descriptions of the imaginary exponential signal 
is NOT CORRECT ( )
选项：
A: Both the imaginary exponential siganl and sine signal 
are periodic signals with the fundamental peroid of 
.
B: The imaginary exponential signal can be represented as 
C: Both the imaginary exponential siganl and sine signal can be linearly represented by the other signal, and thus, they have the same properties.
D: The greater the 
, the higher the oscillation frequency of the real and imaginary parts of the imaginary exponential signal .
答案: 【 The imaginary exponential signal can be represented as 】
3、单选题：
Given the waveform of a signal 
, as shown below, it can be represented as ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
4、单选题：
= ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
5、单选题：
The value of the integral 
is ( )
选项：
A: 0
B: 4
C: -4
D: 2
答案: 【 0】
6、单选题：
Which one of the below relations is WRONG ( ) ?
选项：
A: 
B: 
C: 
D: 
答案: 【 】
7、单选题：
Which one of the below descriptions of the imaginary exponential sequence 
is WRONG ( )?
选项：
A: The imaginary exponential sequence is not necessarily periodic.
B: The imaginary exponential sequence and sinusoidal sequences can represent each other using the Euler's relation.
C: The imaginary sequence can be obtained by sampling from the continuous-time signal 
, therefore, they should have the same period.
D: The amplitude of the imaginary exponential sequence may not increase as the angular frequency increases.
答案: 【 The imaginary sequence can be obtained by sampling from the continuous-time signal , therefore, they should have the same period.】
8、单选题：
Which one of the below relations is WRONG ( ) ?
选项：
A: 
B: 
C: 
D: 
答案: 【 】
9、单选题：
Given the waveform of a signal 
shown below, the signal can be represented by using 
and 
as ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
10、单选题：
Given the waveform of a signal 
shown below, the waveform of 
should be ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
11、单选题：
The waveform of a signal is shown below. What is the waveform of 
( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
12、单选题：
If 
, then 
=( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
13、单选题：
Given the waveform of the signal shown below, which one of the representation of is WRONG ( )
选项：
A: 
B: 
C: 
D: 
答案: 【 】
14、单选题：
If a dicrete-time sequence 
, then which of the four expressions is NOT the even component of （ ）
选项：
A: 
B: 
C: 
D: 
答案: 【 】
CHAPTER III - System Analysis in the Time Domain
Test on Chapter 3
1、单选题：
The waveform of a continuous-time signal is shown below. What frequency components does the signal have?
选项：
A: Cosine components for all harmonics
B: Sine components for all harmonics
C: Sine components for odd harmonics
D: Cosine components for odd harmonics
答案: 【 Sine components for odd harmonics】
2、单选题：
Given the spectrum 
of a continuous-time signal is shown below, then, the periodic signal signal 
选项：
A: 
B: 
C: 
D: 
答案: 【 】
3、单选题：
For a periodic signal 
shown below, the DC component is
选项：
A: 0
B: 2
C: 2.5
D: 4
答案: 【 2.5】
4、单选题：
The average power of the periodic continuous-time signal 
is
选项：
A: 6
B: 6.5
C: 8
D: 8.5
答案: 【 6.5】
5、单选题：
The spectrum of a non-periodic continuous-time signal is
选项：
A: continuous and non-periodic
B: continuous and periodic
C: discrete and non-periodic
D: discrete and perodic
答案: 【 continuous and non-periodic】
6、单选题：
The Fourier transform of signal 
is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
7、单选题：
Given a signal
, the value of the spectrum 
at 
, 
is
选项：
A: 0
B: 4
C: 8
D: 16
答案: 【 8】
8、单选题：
If the bandwidth of a band-limited signal 
is 
, then the bandwidth of the signal 
is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
9、单选题：
The highest angular frequency of the spectrum 
of one signal 
is 
, and the highest angular frequency of the spectrum 
of a second signal 
is 
. Then, the highest angular frequency of the signal 
is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
10、单选题：
A signal 
is shown below. The spectrum 
of the signal is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
11、单选题：
If the highest frequency of a real signal 
is 100Hz, then the highest frequency of the signal 
is
选项：
A: 100Hz
B: 150Hz
C: 200Hz
D: 400Hz
答案: 【 150Hz】
12、单选题：
The energy of the signal 
is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
13、单选题：
If the Fourier transform of the signal 
shown in Figure (a) is 
. Then the Fourier transform of the signal 
in Figure (b) is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
14、单选题：
The spectrum of the signal 
is 
. Then the spectrum of the signal 
is 
选项：
A: 
B: 
C: 
D: