大学MOOC Engineering Electromagnetics(Beijing Jiaotong University)1461338168 最新慕课完整章节测试答案
Ch 1 Fields
1.1 Quiz (Gradient of a Scalar Field)
1、单选题：
About gradient, which one is right?
选项：
A: Gradient of a scalar field is a scalar.
B: The magnitude of a gradient is the maximum change rate of the scalar function.
C: The direction of a gradient is the direction of the directional derivative.
D: The gradient of a constant is not certain.
答案: 【 The magnitude of a gradient is the maximum change rate of the scalar function.】
2、单选题：
About the relationship between gradient and directional derivative of a scalar field, which one is right?
选项：
A: The magnitude of a gradient is the maximum value of the scalar function at the point, and its direction is the direction in which the scalar function changes the most slowly.
B: The magnitude of a gradient is the minimum change rate of the scalar function at this point, and its direction is the reverse direction of the maximum change of the scalar function.
C: The magnitude of a gradient is the maximum change rate of the scalar function at this point, and its direction is the direction in which the scalar function is increasing the most rapidly.
D: The magnitude of a gradient is the minimum value of the scalar function at this point, and its direction is the direction in which the scalar function is increasing the most rapidly.
答案: 【 The magnitude of a gradient is the maximum change rate of the scalar function at this point, and its direction is the direction in which the scalar function is increasing the most rapidly.】
3、单选题：
About gradient and directional derivative, which one is false?
选项：
A: Along the direction of the gradient, change rate of the scalar is the maximum.
B: The directional derivative is the maximum in the direction of the gradient.
C: If the directional derivative is positive, the function increases in this direction.
D: The directional derivative of a scalar function at a given point is unique.
答案: 【 The directional derivative of a scalar function at a given point is unique.】
4、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
5、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
1.2 Quiz (Divergence of a Vector Field)
1、单选题：
Which one is false?
选项：
A: Divergence of a vector field is a scalar.
B: Divergence of a scalar field is a scalar.
C: If divergence of a vector field at one point is positive, there is a positive source at this point
D: If divergence of a vector field at one point is zero, there is no source at this point.
答案: 【 Divergence of a scalar field is a scalar.】
2、单选题：
选项：
A: 1
B: 2
C: 3
D: 4
答案: 【 2 】
3、单选题：
选项：
A: 10
B: 8
C: 12
D: 14
答案: 【 8】
4、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
1.3 Quiz (Curl of a Vector Field)
1、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
2、单选题：
When a vector field satisfies ( ), it can be expressed by the gradient of a scalar field.
选项：
A: 
B: 
C: 
D: 
答案: 【 】
3、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
Ch 2 Electrostatic Fields
2.1 Quiz (Electric Field Intensity of Electrostatic Field)
1、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
2、单选题：
A point charge q in vacuum is located at the coordinate origin. The electric field intensity at P (0, 2, 2) produced by the point charge is
选项：
A: 
B: 
C: 
D: 
答案: 【 】
3、单选题：
选项：
A: It is proportional to r.
B: It is inversely proportional to r.
C: 
D: It is independent of r.
答案: 【 】
4、单选题：
The radius of a uniformly charged conducting sphere is R and the charge quantity is Q. The electric field intensity inside the conductor is
选项：
A: 0
B: 
C: 
D: 
答案: 【 0】
2.10 Quiz(The Method of Electric Axes)
1、单选题：
选项：
A: The method of electric axes is applicable for the region inside and outside the conducting cylinders.
B: 
C: 
D: The essence of the method of electric axes is to replace the induced charge distribution on the conductor surfaces with the imaginary concentrated line charges outside the field boundary.
答案: 【 The essence of the method of electric axes is to replace the induced charge distribution on the conductor surfaces with the imaginary concentrated line charges outside the field boundary.】
2、单选题：
选项：
A: 
B: 
C: 
D: 
答案: 【 】
3、判断题：
We can use the Gauss’s law and superposition principle to calculate the electric field of two parallel infinite line charges.
选项：
A: 正确
B: 错误
答案: 【 正确】
4、判断题：
选项：
A: 正确
B: 错误
答案: 【 错误】
5、判断题：
The introduction of imaginary concentrated line charges must keep the original boundary conditions unchanged.
选项：
A: 正确
B: 错误
答案: 【 正确】
6、判断题：
The theoretical basis of the method of electric axes is the uniqueness theorem.
选项：
A: 正确
B: 错误
答案: 【 正确】
7、判断题：
The method of electric axes can be used to solve the external electric field of two long parallel charged conducting cylinders with different radii.
选项：
A: 正确
B: 错误
答案: 【 正确】
2.11 Quiz(Capacitance)
1、单选题：
The capacitance of a capacitor is related to
选项：
A: the voltage of the capacitor
B: the charge of the capacitor
C: the shape and dielectric of the capacitor
D: the electric field intensity of the capacitor
答案: 【 the shape and dielectric of the capacitor】
2、单选题：
About capacitance, which is false?
选项：
A: Capacitance is the ratio of the magnitude of the charge on either conductor to the magnitude of the potential difference between two conductors.
B: Capacitance is only related to the charge.
C: Capacitance is independent of the potential and total charge of the capacitor.
D: A capacitor is a device that stores electric energy, usually consisting of two conductors.
答案: 【 Capacitance is only related to the charge.】
3、单选题：