Figure 31.26 is attached for question 6

1. Write down the four Maxwell's equations and label each of them with their names. 2. Write down the Lorentz force law, which combines both electric and magnetic forces. 3. Use the values of \\epsilon_0 and \\mu_0 to calculate the speed of light. 4. Write down the five properties of electromagnetic waves described in the text. 5. What is the Poynting vector and what are its two important properties? 6. An electromagnetic wave is created by an antenna much like the one in Fig. 31.26, oriented vertically (up-down). In what direction does the electric field oscillate? What direction does the magnetic field oscillate? What direction is the polarization of the resulting electromagnetic wave?FIGURE 31.26 An antenna generates a self-sustaining electromagnetic wave. switching position at frequency f, then E would oscillate in a vertical plane. The changing E would then create an induced magnetic field B, which could then create an E, which An oscillating voltage causes the dipole to oscillate. could then create a B.. . . , and an electromagnetic wave at frequency f would radiate out into space. This is exactly what an antenna does. FIGURE 31.26 shows two metal wires attached to the terminals of an oscillating voltage source. The figure shows an instant when the top wire is negative and the bottom is positive, but these will reverse in half a cycle. The wire is basically an oscillating dipole, and it creates an oscillating electric field. O The oscillating E induces an oscillating B, and they take off as an electromagnetic wave at speed Vem = c. The wave does need oscillating charges as a wave source, but once created it is self-sustaining and independent of the source. The antenna might be + + destroyed, but the wave could travel billions of light years across the universe, bearing Antenna The oscillating dipole causes an the legacy of James Clerk Maxwell. wire electromagnetic wave to move away from the antenna at speed Vem = C