Question

A microwave source produces pulses of 25.0 GHz radiation, with each pulse lasting 1.00 ns. A parabolic reflector with a face area of radius R = 7.00 cm is used to focus the microwaves into a parallel beam of radiation, as shown in the figure below. The average power during each pulse is 20.0 kW.

A parabolic reflector is represented as a paraboloid with its concave side facing the right. Four wavy parallel lines of equal frequency and wavelength extend from the concave side of the reflector toward the right. Arrows on the wavy lines indicate the waves are traveling to the right.

(a) What is the wavelength of these microwaves?
cm
(b) What is the total energy contained in each pulse?
µJ
(c) Compute the average energy density inside each pulse.
mJ/m³
(d) Determine the amplitude of the electric field and magnetic field in these microwaves.
E_max =  kV/m
B_max =  µT
(e) Compute the force exerted on the surface during the 1.00 ns duration of each pulse. Assume this pulsed beam strikes an absorbing surface.
µN

Answer 1