The input impedance of a 31-cm-long lossless transmission line The input impedance of a 31-cm-long lossless transmission line of unknown characteristic impedance was measured at 1 MHz. With the line terminated in a short circuit, the measurement yielded an input impedance equivalent to an inductor with inductance of 0.064 ÂľH, and when the line was […]
The electric field radiated by a short dipole antenna is The electric field radiated by a short dipole antenna is given in spherical coordinates by Find H (R = ďą; t)
The electric field phasor of a uniform plane wave is given by The electric field phasor of a uniform plane wave is given by E = y10ej0.2z (V/m). If the phase velocity of the wave is 1.5 x 108 m/s and the relative permeability of the medium is Âľr = 2 4, find (a) The […]
The height of an ocean wave is described by the function The height of an ocean wave is described by the function y(x, t) = 1.5 sin (0.5t -0.6x) (m). Determine the phase velocity and the wavelength and then sketch y(x, t) at t = 2s over the range from x = 0 to x […]
The electric field of an electromagnetic wave propagating in air The electric field of an electromagnetic wave propagating in air is given by Find the associated magnetic field H (z. t)
The figure depicts a half-wave dipole connected to a generator The figure depicts a half-wave dipole connected to a generator through a matched transmission line. The directivity of the dipole can be modified by placing a reflecting rod a distance d behind the dipole. What would its reflectivity in the forward direction be if: (a) […]
Determine the room temperature heat capacities at constant (a) Determine the room temperature heat capacities at constant pressure for the following materials: aluminum, silver, tungsten, and 70Cu-30Zn brass. (b) How do these values compare with one another? How do you explain this?
(a) Explain why no hole is generated by the electron (a) Explain why no hole is generated by the electron excitation involving a donor impurity atom. (b) Explain why no free electron is generated by the electron excitation involving an acceptor impurity atom.
From the galvanic series (Table 17.2), cite three metals (a) From the galvanic series (Table 17.2), cite three metals or alloys that may be used to galvanically protect 304 stainless steel in the active state. (b) As Concept Check 17.4(b) notes, galvanic corrosion is prevented by making an electrical contact between the two metals in […]
(a) In your own words describe briefly the phenomenon (a) In your own words describe briefly the phenomenon of luminescence. (b) What is the distinction between fluorescence and phosphorescence?