110年 - 110 國立臺灣科技大學_碩士班招生試題_電子工程系(丙組)：電磁學#112842

科目：研究所、轉學考(插大)◆電磁學 | 年份：110年 | 選擇題數：0 | 申論題數：15

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 (15)

(1)Determine the mutual inductance between the conducting rectangula and a very long straight wire as shown below (10%)

(2)Determine the force acting on the loop with current I₁ on the current I₂ on the very long straight wire? (10%)

(1)Find the electric field at a point located at the center a semicircle n linear charge density p and with a radius R as shown below.(10%)

(2)Find the electric potential of that point, assuming the potential at infi distance is zero.(10%)

3. (10%)Please write down the divergence (∇ㆍ ) of a vector field A in spherical coordinate. (10%)

(1). Please define the critical angle. (5%)

(2). When does the total reflection exist at an interface of two nonmagnetic media with μ₁ = μ₂ = μ₀?(5%)

(1). Please find the value of ε₂ for which the Brewster's angle=60°. (5%)

(2). Please find the value of ε₂ for which the critical angle for the total internal reflection =60°. (5%)

(1). What is the frequency fof this infrared light? (5%)

(2). What is the propagation constant (i.e. phase constant) β(rad/m) of this electromagnetic wave? (5%)

(3). If the magnitude of the wave's electric field intensity doubles, how should the power flow density change? (5%)

(1). What is the physical meaning of the "skin depth"? (5%)

(2). What is the ratio of the "skin depth" in copper at f= 1 MHz to that at f = 100 MHz? (5%)

(3). For underwater communication, which frequency band would be better, higher band or lower one? Why? (5%)