Shown below are pictorial and mathematical representations of an electromagnetic

Question

Shown below are pictorial and mathematical representations of an electromagnetic plane wave propagating through empty space. The electric field is parallel to the z-axis; the magnetic field is parallel to the y-axis. A long, thin conducting wire (see figure at right) is placed in the path of a radio wave that can be represented as in section I. Suppose that the wire were oriented parallel to the z-axis. As the wave moves past the wire, would the electric field due to the radio wave cause the charges in the wire to move? If so, would the charges move in a direction along the length of the wire? Explain. As the wave moves past the wire, would the magnetic field due to the wave cause the charges in the wire to move in a direction along the length of the wire? Explain.

Explanation / Answer

ITEM#1: If wire is oriented parallel to "z" axis, thewire will be parallel to the oscillating E field when wave moves across the wire. This E field will exert a force on wire electrons which causes them to oscillate with the E field. Since this force is parallel to the E field,which in turn is parallel to the wire's length, wire electrons will oscillate along the wire's length. If wire isoriented parallel to "z" axis, the wire will be perpendicular to the oscillating magnetic field when wave moves across the wire. By Faraday's Law, the changing magnetic flux will induce circular current loops which cancel each other over the wire's length. Hence, the wave's oscillating magnetic field will NOTcause electrons to oscillate along the wire's length. .

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.