92年 - 92 淡江大學轉學考電磁學#56058

科目：研究所、轉學考(插大)◆電磁學 | 年份：92年 | 選擇題數：0 | 申論題數：10

試卷資訊

所屬科目：研究所、轉學考(插大)◆電磁學

選擇題 (0)

申論題 (10)

【已刪除】 (a) Find the electric field

and potential (V) as a function of the radial distance (r) from the center of the sphere.

(b) Calculate the electrostatic energy of the system. (20%)

【已刪除】2. Assume that a static charge distribution (ρ) produces an electric potential V

， where A and a are positive constants,

is the position vector, r = |

|. Now, it is given that ▽²(1 /r) = -4πδ(

). Find the electric field

and the total charge Q. (20%)

【已刪除】3. Jusitify that the vector potential of a uniform magnetic field

may be expressed as

(10 %)

(a) Justify that the magnetic field (whenever nonzero) is in the z-direction.

【已刪除】(b)Show that

(the magnetic flux through a surface enclosed by a closed path C), c where

is the vector potential.

(c) Find the magnetic field intensity (H) and vector potential throughout the space. (20%)

(a) Write down the corresponding integral form for each of the four Maxwell’s equations, and specify the physical meaning for each of them.

【已刪除】(b) Show that the free charge density and free current density satisfy the continuity quation:

(Hint: Two of the Maxwell equations may be useful).

(c) Show that the tangential component of the electric field must be continuous across any boundary surface. (30 %)