大学MOOC Engineering Electromagnetics(Harbin Institute of Technology)1461269162 最新慕课完整章节测试答案

01_01 Quiz

1、单选题：

‍In Cartesian coordinate system,  refers to the vector from point (2,4,1) to point (0,2,0), then the unit vector of  is (   )

‌选项：
A:
B:
C:
D:
答案: 【 】

2、单选题：

​Known , , then  is (   )

‍选项：
A:
B: -2
C:
D: -12
答案: 【 -2】

3、单选题：

​Known , , then  is (   )

‏选项：
A:
B: -2
C:
D: -12
答案: 【 】

4、单选题：

‏Known  ,  , then vector  and  (   )

‎选项：
A: orthogonal
B: parallel
C: form an acute angle
D: form an obtuse angle
答案: 【 orthogonal】

5、单选题：

‎Known  and  is parallel everywhere, then (   )

‎选项：
A:
B:
C:
D:
答案: 【 】

01_02 Quiz

1、单选题：
‌The field that does not change with time is called (   )‏
选项：
A: Time-varying field
B: Dynamic field
C: Quasi-state field
D: Static field
答案: 【 Static field】

2、单选题：
‌In the scalar field, the surface composed of points with equal function value is called (   )​
选项：
A: Vector line
B: Isosurface
C: Equal format
D: Equal phase
答案: 【 Isosurface】

3、单选题：

​Given the scalar field  , the isosurface equation is (   )

‍选项：
A:
B: (where C is a constant)
C:
D: (where C is a constant)
答案: 【 (where C is a constant)】

4、单选题：
‎In the vector field, the vector line is such a curve where (   )‌
选项：
A: The tangent direction at each point on it is orthogonal to the direction of the vector field at that point.
B: The tangent direction at each point on it is parallel to the direction of the vector field at that point.
C: The value of each point on it is equal to the value of the vector field at that point.
D: The vector line is the geometric curve of the vector field function.
答案: 【 The tangent direction at each point on it is parallel to the direction of the vector field at that point.】

5、单选题：

‏The vector line equation of the vector field  is(    )

‎选项：
A:
B:
C:
D:
答案: 【 】

01_03 Quiz

1、单选题：

‍Regarding the directional derivative  , which of the following statements is wrong?

‌选项：
A: The changing rate of function  from point  to point  along  is called directional derivative.
B: When the directional derivative  , function  is increased along  .
C: When the directional derivative  , function  is increased along  .
D: The directional derivative of function at a given point is unique.
答案: 【 The directional derivative of function at a given point is unique.】

2、单选题：

‏Known a scalar function , vector  , then the directional derivative of the scalar function  at point (2,-1,1) along vector  is (     )

‏选项：
A: 1
B: -1
C:
D:
答案: 【 】

3、单选题：
‍Regarding the gradient, which of the following statements is wrong?‌
选项：
A: The gradient of a scalar field is a vector and a function of spatial coordinate points.
B: The magnitude of the gradient at a certain point is the maximum changing rate of the scalar function  at that point.
C: The direction of the gradient at a point is the normal vector of the isosurface which passing through the point.
D: The directional derivative of scalar function  along  is the projection of vector  on the gradient.
答案: 【 The directional derivative of scalar function  along  is the projection of vector  on the gradient.】

4、单选题：

‎Given  ,then  (    )

‌选项：
A:
B:
C:
D:
答案: 【 】

5、单选题：

‎Given the scalar field  ,  then the maximum directional derivative of  at point (2,1,3) is (   )

‎选项：
A: 8
B: 15
C:
D: 117
答案: 【 】

01_04 Quiz

1、单选题：
‏Regarding the Hamiltonian Operator, which of the following statement is wrong?‏
选项：
A: Hamiltonian Operatoris just a calculating sign and it has no meaning itself.
B: Hamiltonian Operatoronly effects on the quantity on the right, not the left.
C: Hamiltonian Operatoris a combination of derivative and vector, so it has both derivative properties and vector features.
D: The expression of the Hamiltonian Operatoris identical though in different coordinates.
答案: 【 The expression of the Hamiltonian Operatoris identical though in different coordinates.】

2、单选题：

‎For any scalar field ,(    )

‌选项：
A: Constantly equal to 0
B: Sometimes equal to 0
C: Has a singular result
D: The result cannot be determined, but it must be a finite value.
答案: 【 Constantly equal to 0】

3、单选题：

‎For any vector field,(    )

‏选项：
A: Constantly equal to 0
B: Sometimes equal to 0
C: Has a singular result
D: The result cannot be determined, but it must be a finite value.
答案: 【 Constantly equal to 0】

4、单选题：

​refers to the distance vector from source point to field point,then=(    )

‌选项：
A: 3
B: 0
C:
D:
答案: 【 0】

5、单选题：
‍Which of the following statements is wrong about the Laplace Operator?​
选项：
A:
B:
C:
D:
答案: 【 】

01_05 Quiz

1、单选题：

‏As shown in the picture, the flux of the uniform vector field passes through the hemisphere with radius R is (   )

‎

‏

‎选项：
A:
B:
C:
D:
答案: 【 】

2、单选题：
‏Which of the following statements is wrong about divergence?‍
选项：
A: The divergence of a vector field is a scalar and a function of the spatial coordinate points.
B: At point M in the field, if then it means that there is a positive source which emit flux lines at that point.
C: At point M in the field, ifthen it means that there is a negative source which collect flux lines at that point.
D: At point M in the field, ifthen it means that there is neither positive source nor negative source at that point. We call a passive field.
答案: 【 At point M in the field, ifthen it means that there is neither positive source nor negative source at that point. We call a passive field.】

3、单选题：

‍Known vector ,then (     )

‎选项：
A:
B:
C:
D:
答案: 【 】

4、单选题：

‌The divergence of the gradient field of the scalar field is(     )

‍选项：
A:
B:
C:
D: 0
答案: 【 】

5、单选题：

‌As shown in the picture, the divergence of  point  is(     )

​

‌

​选项：
A: Above 0
B: Below 0
C: Equal to 0
D: Not able to decide positive or negative
答案: 【 Above 0】

01_06 Quiz

1、单选题：
‏Which of the following statements is wrong about curl?​
选项：
A: The curl of a vector field is a scalar and a function of the spatial coordinate points.
B: At a certain point M in the field, means that the vector line of this point is spinning.
C: At a certain point M in the field, means that the vector line of this point is spinless.
D: Curl have the dimension of circumferential area density.
答案: 【 The curl of a vector field is a scalar and a function of the spatial coordinate points.】

2、单选题：
‏Which of the following statements is wrong?‌
选项：
A: At a point M in the field, it can be determined whether there is a vortex source in the closed curve according to the magnitude of the circulation at point M.
B: At a point M in the field, the circumferential surface density reflects the strength of the vector rotating around the specified direction at point M.
C: At a point M in the field, the circumferential surface density at point M is unique.
D: At a point M in the field, the circumferential surface density in any direction passing through the point M can be obtained by the projection of the curl in that direction.
答案: 【 At a point M in the field, the circumferential surface density at point M is unique.】

3、单选题：

‌Known vector   , the curl of   at point  is (     )

​选项：
A:
B:
C:
D:
答案: 【 】

4、单选题：

‏Known vector   , the circumferential density at point  along  is (     )

​选项：
A:
B:
C:
D:
答案: 【 】

5、单选题：

‎As shown in the picture, which of the description about point M is right?

‏

‎

‏选项：
A: , 
B: , 
C:  , 
D:  , 
答案: 【  , 】

01_07 Quiz

1、单选题：

‏Helmholtz theorem shows that, in a vector field  in a single connected region  V  in a finite space, which of the following statements is right?

‍选项：
A: The vector field  is uniquely determined by its divergence and rotation
B: The vector field  is uniquely determined by its divergence and the boundary conditions
C: The vector field  is uniquely determined by its curl and the boundary conditions
D: The vector field  is uniquely determined by its divergence, curl and boundary conditions
答案: 【 The vector field  is uniquely determined by its divergence, curl and boundary conditions】

2、单选题：

‎Helmholtz theorem shows that, in a vector field  in a single connected region V  in a finite space, which of the following statements is right?

‏选项：
A: The vector field  can be expressed as the sum of the gradient of a scalar function and a vector function
B: The vector field  can be expressed as the sum of the gradient of a scalar function and the divergence of a vector function
C: The vector field  can be expressed as the sum of the gradient of a scalar function and the curl of a vector function
D: The vector field  can be expressed as the sum of an irrotational field and a scattered field
答案: 【 The vector field  can be expressed as the sum of an irrotational field and a scattered field】

Chapter01 Test

1、单选题：

​Given the scalar field  , the isosurface equation through point M(1,0,1) is (     )

‎选项：
A:
B:
C:
D:
答案: 【 】

2、单选题：

‏Vector line equation of vector field  passing through point M(1,2,3) (    )

‌选项：
A:
B:
C:
D:
答案: 【 】

3、单选题：

​The velocity field of liquid is known as , then there is （   ） at point M(1,2,3)

‎选项：
A: no way to judge whether there is a source
B: no source
C: a negative source
D: a positive source
答案: 【 a positive source】

4、单选题：

‎As shown in the picture, which of the description about point M is right?

‌

‎

‌选项：
A:
B:
C:
D:
答案: 【 】

5、单选题：

‎Known  ,  , then (     )

‏选项：
A:
B:  ( is the angle between and )
C:
D:
答案: 【 】

6、单选题：

​Known  ,  , then (     )

‎选项：
A:
B:
C:
D:
答案: 【 】

7、单选题：

​Given the scalar field , when the point satisfies , the point and direction where has the maximum changing rate are(     )

‎选项：
A: The point where  has the maximum changing rate is (0,1) , and the direction is 
B: The point where  has the maximum changing rate is (1,0) , and the direction is 
C: The point where  has the maximum changing rate is (1,0) , and the direction is  , or the point where  has the maximum changing rate is (-1,0) , and the direction is 
D: The point where  has the maximum changing rate is (0,1) , and the direction is  , or the point where  has the maximum changing rate is (0,-1) , and the direction is 
答案: 【 The point where  has the maximum changing rate is (1,0) , and the direction is  , or the point where  has the maximum changing rate is (-1,0) , and the direction is 】

8、单选题：

‌The divergence of the gradient field of the scalar field  is (     )

‏选项：
A:
B:
C:
D:
答案: 【 】

9、单选题：
​which of the following statements is right?(     )‏
选项：
A: The divergence of a vector field is a vector field
B: The gradient of a scalar field is a scalar field
C: The gradient of a scalar field is a vector field
D: The curl of a vector field is a scalar field
答案: 【 The gradient of a scalar field is a vector field】

10、单选题：
‌The expression of divergence theorem is (     )‏
选项：
A:
B:
C:
D:
答案: 【 】

11、单选题：

‏Given scalar field , the gradient of at point (-1,3,-2) is (    )

‍选项：
A:
B: