/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q40P Consider the resonant cavity pro... [FREE SOLUTION] | 91影视

91影视

Consider the resonant cavity produced by closing off the two ends of a rectangular wave guide, at z=0and at z=d, making a perfectly conducting empty box. Show that the resonant frequencies for both TE and TM modes are given by

role="math" localid="1657446745988" lmn=c(ld)2+(ma)2+(nb)2(9.204)

For integers l, m, and n. Find the associated electric and magnetic fields

Short Answer

Expert verified

The resonant frequencies for both TE and TM modes are

=cma2+nb2+ld2,the associated electric field is

Ex=Bcoskxxsinkzzx^+Dsinkxxcoskyysinkzzy^+Fsinkxxsinkyycoskzzz^, and the

associated magnetic field isB=-iFky-Dkzsinkxxcoskyycoskzzx^-iBkz-Fkxcoskxxsinkyycoskzzy^-iDkx-Bkycoskxxcoskyysinkzzz^.

Step by step solution

01

Expression for the resonant frequencies for both TE and TM mode:

Write the expression for the resonant frequencies for both TE and TM mode.

2=c2(kx2+ky2+kz2) 鈥︹ (1)

Here, c is the speed of light and k is the wave number

Here, the value of kx, kyand kzare given as:

role="math" localid="1657449389970" kx=maky=nbkz=Id

02

Prove the expression for resonant frequencies for both TE and TM mode:

Substitutekx=ma,ky=nband kz=ldin equation (1).

localid="1657450941973" 2=c2ma2+nb2+ld2

=cma2+nb2+ld2

03

Determine the associated electric field:

Write the expression for the x, y, and z components of an electric field.

Ex(x,y,z)=Asinkxx+BcoskxxsinkxysinkzzEy(x,y,z)=sinkxxCsinkyy+DcoskyysinkzzEz(x,y,z)=sinkxxsinkyyEsinkzz+Fcoskzz

Hence, the associated electric field will be,

Ex=Bcoskxxsinkzzx^+Dsinkxxcoskyysinkzzy^+Fsinkxxsinkyycoskzzz^

04

Determine the associated magnetic field:

Write the expression for the x component of a magnetic field.

Bx=-iEzy-Eyz

Substitute the value of and in the above expression.

Bx=-iFkysinkxxcoskyycoskzz-Dkzsinkxxcoskyycoskzz

Write the expression for the y component of a magnetic field.

By=-iExz-Ezx

Substitute the value of Exand Ezin the above expression.

By=-iBkzcoskxxsinkyycoskzz-Fkxcoskxxsinkyycoskzz

Write the expression for the z component of a magnetic field.

Bz=-iEyx-Exy

Substitute the value of Eyand Ezin the above expression.

Bz=-iDkxcoskxxcoskyysinkzz-Bkycoskxxcoskyysinkzz

Hence, the associated magnetic field will be,

B=-iFky-Dkzsinkxxcoskyycoskzzx^-iBkz-Fkxcoskxxsinkyycoskzzy^-iDkx-Bkycoskxxcoskyysinkzzz^

Therefore, the resonant frequencies for both TE and TM modes are

=cma2+nb2+ld2,the associated electric field is

Ex=Bcoskxxsinkzzx^+Dsinkxxcoskyysinkzzy^+Fsinkxxsinkyycoskzzz^,and the associated magnetic field isB=-iFky-Dkzsinkxxcoskyycoskzzx^-iBkz-Fkxcoskxxsinkyycoskzzy^-iDkx-Bkycoskxxcoskyysinkzzz^

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

(a) Shallow water is non-dispersive; waves travel at a speed that is proportional to the square root of the depth. In deep water, however, the waves can鈥檛 鈥渇eel鈥 all the way down to the bottom鈥攖hey behave as though the depth were proportional to 位. (Actually, the distinction between 鈥渟hallow鈥 and 鈥渄eep鈥 itself depends on the wavelength: If the depth is less than 位, the water is 鈥渟hallow鈥; if it is substantially greater than 位, the water is 鈥渄eep.鈥) Show that the wave velocity of deep water waves is twice the group velocity.

(b) In quantum mechanics, a free particle of mass m traveling in the x direction is described by the wave function

(x,t)=Aei(px-Et)

wherep is the momentum, and E=p2/2mis the kinetic energy. Calculate the group velocity and the wave velocity. Which one corresponds to the classical speed of the particle? Note that the wave velocity is half the group velocity.

A microwave antenna radiating at 10GHzis to be protected from the environment by a plastic shield of dielectric constant2.5. . What is the minimum thickness of this shielding that will allow perfect transmission (assuming normal incidence)? [Hint: Use Eq. 9.199.]

Show that the modeTE00 cannot occur in a rectangular wave guide. [Hint: In this casec=k , so Eqs. 9.180 are indeterminate, and you must go back to Eq. 9.179. Show that is a constant, and hence鈥攁pplying Faraday鈥檚 law in integral form to a cross section鈥攖hatBz=0 , so this would be a TEM mode.]

If you take the model in Ex. 4.1 at face value, what natural frequency do you get? Put in the actual numbers. Where, in the electromagnetic spectrum, does this lie, assuming the radius of the atom is 0.5 脜? Find the coefficients of refraction and dispersion, and compare them with the measured values for hydrogen at 0Cand atmospheric pressure:A=1.3610-4,B=7.710-15m2 .

(a) Suppose you imbedded some free charge in a piece of glass. About how long would it take for the charge to flow to the surface?

(b) Silver is an excellent conductor, but it鈥檚 expensive. Suppose you were designing a microwave experiment to operate at a frequency of1010Hz. How thick would you make the silver coatings?

(c) Find the wavelength and propagation speed in copper for radio waves at role="math" localid="1655716459863" 1MHz. Compare the corresponding values in air (or vacuum).

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.