Electromagnetic Waves

A plane electromagnetic wave of frequency 20 MHz travels in free space along the +x direction. At a particular point in space and time, the electric field vector of the wave is Ey=9.3 V m-1. Then, the magnetic field vector of the wave at that point is

1. Bz=1.55 10-8 T
2. Bz=6.2 10-8 T
3. Bz=3.1 10-8 T
4. Bz=9.3 10-8 T

A time varying potential difference is applied between the plates of a parallel plate capacitor of capacitance 2.5 . The dielectric constant of the medium between the capacitor plates is 1 . It produces an instantaneous displacement current of 0.25 mA in the intervening space between the capacitor plates, the magnitude of the rate of change of the potential difference will be V s-1.

A parallel plate capacitor of area A=16 cm2 and separation between the plates 10 cm , is charged by a DC current. Consider a hypothetical plane surface of area A0=3.2 cm2 inside the capacitor and parallel to the plates. At an instant, the current through the circuit is 6A. At the same instant the displacement current through A0 is mA .