Introduction To Health Physics
5th Edition
ISBN: 9780071835275
Author: Johnson, Thomas E. (thomas Edward), Cember, Herman.
Publisher: Mcgraw-hill Education,
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Question
Chapter 2, Problem 2.29P
(a)
To determine
What is the amplitude of the magnetic field vector if the maximum amplitude of the electric vector in a plane wave in free space is 275 V/m?
(b)
To determine
What is the rms value of the electric vector?
(c)
To determine
What is the power density, in mW/cm2, in this
Expert Solution & Answer
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Students have asked these similar questions
(a)
The magnetic field intensity H of an electromagnetic wave propagating in
free space in the z-direction is described in phasor form by H = îH¸e¯i
where B is its phase constant. Determine the corresponding electric field from
Ampere's law.
A long straight wire in air carries a current of 5 A. What is the magnetic field
intensity H at a radial distance of 5 m from the wire?
(b)
A battery of open circuit voltage 2 V and internal resistance 50 2 is connected
via a rapid switch to a transmission line of characteristic impedance 50 N
terminated in a load of 100 N. Calculate the voltage and current on the line
just after the switch is closed, explaining your answer carefully.
(c)
The magnetic field in a plane electromagnetic wave is represented by the equation B = Bmax sin(ky - wt)î where Bmax = 2.94 x 10 T and k = 5.86 x 10' /m. (Assume a standard xyz right-handed coordinate system.)
(a) What is the magnitude and direction of the electric field at the instant the magnetic field is a maximum? (Express your answer in vector form.)
Emax - 88.2k
V/m
(b) What is the wavelength of the wave?
10.7
How is the wavelength of EM waves related to the wave number? nm
(c) What is the frequency of the wave?
2.80E-15
How is the frequency related to the wavelength? Hz
The general equation for the electric and the magnetic field as per the electromagnetic
theory is,
E= Emar, cos (kx –- ot)
B| = Bmar. Cos (kx – ox)
The energy per unit volume in an electric field is,
1
UE
The energy per unit volume in a magnetic field is,
1 B
UM
2 Ho
Also, the energy density and the total energy associated with the magnetic field and the
1
(E×B).
Ho
electric field are equal. The rate with the energy flows in an EM wave is S =-
In the positive x direction, a plane EM wave varies sinusoidally at 99 MHz and the peak
value of the electric field is 2 mV/m and it is moving in the ty direction. The wavelength
and period of the wave is,
(а) 3.03 m, 0.01 us
(b) 1.3 m, 0.01 s
(c) 2.1 m, 10s
(d) 1.11 m, 0.55 s
Chapter 2 Solutions
Introduction To Health Physics
Ch. 2 - Two blocks of mass 0.1 kg and 0.2 kg approch each...Ch. 2 - A bullet whose mass is 50 g travels at a velocity...Ch. 2 - Compute the mass of the Earth, assuming it to be a...Ch. 2 - An automobile weighing 2000 kg and going at a...Ch. 2 - A small electrically charged sphere of mass 0.1 g...Ch. 2 - A capacitor has a capacitance of 10F . How much...Ch. 2 - A small charged particle whose mass is 0.01 g...Ch. 2 - Prob. 2.8PCh. 2 - Prob. 2.9PCh. 2 - Prob. 2.10P
Ch. 2 - Prob. 2.11PCh. 2 - Prob. 2.12PCh. 2 - Prob. 2.13PCh. 2 - Prob. 2.14PCh. 2 - Prob. 2.15PCh. 2 - A current of 25 mA flows through a 25-gauge wire,...Ch. 2 - An electron starts at rest on the negative plate...Ch. 2 - Prob. 2.18PCh. 2 - Prob. 2.19PCh. 2 - Prob. 2.20PCh. 2 - Prob. 2.21PCh. 2 - Prob. 2.22PCh. 2 - Prob. 2.23PCh. 2 - (a) A 1000-MW(e) nuclear power plant operates at a...Ch. 2 - Prob. 2.25PCh. 2 - Prob. 2.26PCh. 2 - Prob. 2.27PCh. 2 - The specific heat of water in the English system...Ch. 2 - Prob. 2.29PCh. 2 - Prob. 2.30PCh. 2 - Prob. 2.31PCh. 2 - Prob. 2.32PCh. 2 - How many cubic meters of water must fall over a...Ch. 2 - (a) Calculate the speed of a 25-MeV proton. (b)...Ch. 2 - Prob. 2.35PCh. 2 - Prob. 2.36PCh. 2 - Calculate the speed of a (a) 0.5-MeV electron and...Ch. 2 - How much sub-butuminous coal (20,000 kJ/kg) would...Ch. 2 - Prob. 2.40PCh. 2 - How much oil (138,690 Btu/gal) would it take to...Ch. 2 - How much oil (138,690 Btu/gal) would it take to...Ch. 2 - Prob. 2.43PCh. 2 - Prob. 2.44PCh. 2 - Prob. 2.45PCh. 2 - Prob. 2.46PCh. 2 - Prob. 2.47PCh. 2 - Prob. 2.48PCh. 2 - Prob. 2.49P
Knowledge Booster
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- What is the maximum electric field strength in an electromagnetic wave that has a maximum magnetic field strength of 5.00104 (about 10 times Earth's magnetic field)?arrow_forwardThe electric field of an electromagnetic wave traveling in vacuum is described by the following wave function: E =(5.00V/m)cos[kx(6.00109s1)t+0.40] j where k is the wavenumber in rad/m, x is in m, t s in Find the following quantities: (a) amplitude (b) frequency (c) wavelength (d) the direction of the travel of the wave (e) the associated magnetic field wavearrow_forwardA radio station broadcasts at a frequency of 760 kHz. At a receiver some distance from the antenna, the maximum magnetic field of the electromagnetic wave detected is 2.151011T . (a) What is the maximum electric field? (b) What is the wavelength of the electromagnetic wave?arrow_forward
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