摘要:

The author offers, for those newly entering laboratory society, a simple guide to the proprieties and niceties of conduct therein. Customs dealt with include: making an entry to the laboratory; its arrangement and the nature of the tasks it provides; the proper manner of discovering the nature of those tasks; the fashion after which it is appropriate to regard the manuscript provided; correct behavior in the conduct of the experiment, and the necessities to be observed in recording its outcome; all this, together with more general advice about comportment in the laboratory and the benefits which may be obtained from it. [Editor’snote: The editors have already drafted a letter of response for correspondents who will take this article seriously—and another for those who do not!]

ISSN:0002-9505    

DOI:10.1119/1.10320

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

We describe the construction of simple microwave sources of centimeter wavelength with bulk‐effect diodes and accessory equipment for experiments and demonstrations in physical optics. A peculiar advantage of 1‐cm wavelengths over the longer wavelengths is the high directivity of hand‐sized parabolic reflectors. Thus we emphasize Fraunhofer diffraction. The collimator and telescope of a student spectrometer for light are replaced by a collimator and telescope for centimeter waves. We describe the construction of equipment for demonstrations with centimeter wavelengths on an overhead projector.

ISSN:0002-9505    

DOI:10.1119/1.10321

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The coherence and directional properties of stimulated and spontaneous emission can be understood without a knowledge of quantum electrodynamics. This paper presents a semiclassical description of the interaction between a free atom and a weak optical field under conditions of either a stimulated emission or a stimulated absorption resonance. It is shown that, under certain conditions, the stimulated or spontaneous radiation fields emitted from a sample of atoms will propagate in the same direction as the incident beam, will be coherent with the incident beam, and will have the correct phase to provide amplification or attenuation.

ISSN:0002-9505    

DOI:10.1119/1.10322

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The analog between an optical waveguide coupler and the quantum‐mechanical double‐well problem is established. Well‐known results of the quantum‐mechanical system are applied to the waveguide system. This way of thinking of the waveguide system provides a quick understanding of the coupling mechanism and provides new interpretations of results obtained from Maxwell’s equations. Just as ray opticals give insight into certain types of optics problems, we believe that the tunneling interpretation will give new insight into the field of guided light waves.

ISSN:0002-9505    

DOI:10.1119/1.10323

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The history of the so‐calledopticaltheoremin scattering theory is traced from its beginning over 100 years ago to recent applications of its generalizations.

ISSN:0002-9505    

DOI:10.1119/1.10324

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

A quantum‐mechanical theory using a density matrix for electrical conductivity in the presence of a magnetic field is described. The conventional methods using the Boltzmann transport equation are not satisfactory because the magnetic field introduces a curvature in the free path of an electron. The expectation value of the current density and the components of the conductivity tensor in a magnetic field are obtained. The advantages of the density matrix in electric transport problems with a magnetic field are discussed.

ISSN:0002-9505    

DOI:10.1119/1.10325

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

Electric and magnetic fields induced inside rotating superconductors are explained in terms of the familiar centrifugal and Coriolis forces.

ISSN:0002-9505    

DOI:10.1119/1.10326

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

A simple experiment using an inexpensive RCA 931A photomultiplier is described. This experiment is performed in an elementary physics laboratory and makes a measurement of the secondary electron emission coefficient at the last dynode.

ISSN:0002-9505    

DOI:10.1119/1.10327

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

The employment of a co‐teaching approach in the calculus‐based, first‐year, elementary physics courses has caused many favorable comments by both faculty and students. Student questionnaire responses are presented along with a discussion of the techniques, pitfalls, and advantages of this method of classroom instruction.

ISSN:0002-9505    

DOI:10.1119/1.10328

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP

摘要:

Commercially available permanent magnets have been incorporated in a compact and inexpensive structure providing both field sweep and modulation suitable for electron spin resonance at microwave frequencies.

ISSN:0002-9505    

DOI:10.1119/1.10329

出版商:American Association of Physics Teachers    

年代:1976

数据来源: AIP