Square Van Atta Reflector with Conducting Mounting Plane
... of the reflector in thexz plane (& = 0") , when the incident EtotaliR,0:4i= EPlate(R,f',4) RrefIcctor(R,O,d).('30) plane wave is polarized parallel to t,he dipoles. From the reportmade by Sharp,thecurvedenoted"array"in When describingreradiation or scatt.eringproperties, patt,ern 1 has been redrawn ...
... of the reflector in thexz plane (& = 0") , when the incident EtotaliR,0:4i= EPlate(R,f',4) RrefIcctor(R,O,d).('30) plane wave is polarized parallel to t,he dipoles. From the reportmade by Sharp,thecurvedenoted"array"in When describingreradiation or scatt.eringproperties, patt,ern 1 has been redrawn ...
Ans - WordPress.com
... 67. Explain the failure of classical mechanics. Ans: Classical mechanics failed to explain the following 1) The stability of the atom 2) The spectrum of hydrogen atom 3) Thermal radiation of heated bodies 4) Constancy of light velocity and 5) The origin of photoelectric effect. 68. What is Planck’s ...
... 67. Explain the failure of classical mechanics. Ans: Classical mechanics failed to explain the following 1) The stability of the atom 2) The spectrum of hydrogen atom 3) Thermal radiation of heated bodies 4) Constancy of light velocity and 5) The origin of photoelectric effect. 68. What is Planck’s ...
1 B ⋅ − − = uuua 2 A β
... Among many remarkable qualities of graphene, its electronic properties attract particular interest due to a massless chiral character of charge carriers, which leads to such unusual phenomena as metallic conductivity in the limit of no carriers and the half-integer quantum Hall effect (QHE) observab ...
... Among many remarkable qualities of graphene, its electronic properties attract particular interest due to a massless chiral character of charge carriers, which leads to such unusual phenomena as metallic conductivity in the limit of no carriers and the half-integer quantum Hall effect (QHE) observab ...
+ • C - Purdue Physics
... c) For a 40 kg rider, what is magnitude of centripetal force to keep him moving in a circle? Is his weight large enough to provide this centripetal force at the top of the cycle? d) What is the magnitude of the normal force exerted by the seat on the rider at the top? e) What would happen if the Fer ...
... c) For a 40 kg rider, what is magnitude of centripetal force to keep him moving in a circle? Is his weight large enough to provide this centripetal force at the top of the cycle? d) What is the magnitude of the normal force exerted by the seat on the rider at the top? e) What would happen if the Fer ...
AP Physics 2 Practice Exam and Notes UPDATED
... The exam scoring process, like the course and exam development process, relies on the expertise of both AP teachers and college faculty. While multiple-choice questions are scored by machine, the free-response questions are scored by thousands of college faculty and expert AP teachers at the annual ...
... The exam scoring process, like the course and exam development process, relies on the expertise of both AP teachers and college faculty. While multiple-choice questions are scored by machine, the free-response questions are scored by thousands of college faculty and expert AP teachers at the annual ...
Comprehensive description of deformation of solids as wave dynamics
... load is removed is an example. This postulate indicates that each of these local elastic deformations can be expressed by a transformation that represents Hooke’s law with the local coordinate system (local frame). If the local frame is oriented to the principal axis, the corresponding transformatio ...
... load is removed is an example. This postulate indicates that each of these local elastic deformations can be expressed by a transformation that represents Hooke’s law with the local coordinate system (local frame). If the local frame is oriented to the principal axis, the corresponding transformatio ...
1 Standard I: Motion
... find displacement, determine how far and in which direction the object is from the starting point; we call this quantity displacement. Displacement is a vector, since it includes both a magnitude and a direction. Distance is a scalar quantity giving the positive length between two points. The total ...
... find displacement, determine how far and in which direction the object is from the starting point; we call this quantity displacement. Displacement is a vector, since it includes both a magnitude and a direction. Distance is a scalar quantity giving the positive length between two points. The total ...
Casimir effect
In quantum field theory, the Casimir effect and the Casimir–Polder force are physical forces arising from a quantized field. They are named after the Dutch physicist Hendrik Casimir.The typical example is of two uncharged metallic plates in a vacuum, placed a few nanometers apart. In a classical description, the lack of an external field means that there is no field between the plates, and no force would be measured between them. When this field is instead studied using the QED vacuum of quantum electrodynamics, it is seen that the plates do affect the virtual photons which constitute the field, and generate a net force—either an attraction or a repulsion depending on the specific arrangement of the two plates. Although the Casimir effect can be expressed in terms of virtual particles interacting with the objects, it is best described and more easily calculated in terms of the zero-point energy of a quantized field in the intervening space between the objects. This force has been measured and is a striking example of an effect captured formally by second quantization. However, the treatment of boundary conditions in these calculations has led to some controversy.In fact, ""Casimir's original goal was to compute the van der Waals force between polarizable molecules"" of the metallic plates. Thus it can be interpreted without any reference to the zero-point energy (vacuum energy) of quantum fields.Dutch physicists Hendrik B. G. Casimir and Dirk Polder at Philips Research Labs proposed the existence of a force between two polarizable atoms and between such an atom and a conducting plate in 1947, and, after a conversation with Niels Bohr who suggested it had something to do with zero-point energy, Casimir alone formulated the theory predicting a force between neutral conducting plates in 1948; the former is called the Casimir–Polder force while the latter is the Casimir effect in the narrow sense. Predictions of the force were later extended to finite-conductivity metals and dielectrics by Lifshitz and his students, and recent calculations have considered more general geometries. It was not until 1997, however, that a direct experiment, by S. Lamoreaux, described above, quantitatively measured the force (to within 15% of the value predicted by the theory), although previous work [e.g. van Blockland and Overbeek (1978)] had observed the force qualitatively, and indirect validation of the predicted Casimir energy had been made by measuring the thickness of liquid helium films by Sabisky and Anderson in 1972. Subsequent experiments approach an accuracy of a few percent.Because the strength of the force falls off rapidly with distance, it is measurable only when the distance between the objects is extremely small. On a submicron scale, this force becomes so strong that it becomes the dominant force between uncharged conductors. In fact, at separations of 10 nm—about 100 times the typical size of an atom—the Casimir effect produces the equivalent of about 1 atmosphere of pressure (the precise value depending on surface geometry and other factors).In modern theoretical physics, the Casimir effect plays an important role in the chiral bag model of the nucleon; in applied physics, it is significant in some aspects of emerging microtechnologies and nanotechnologies.Any medium supporting oscillations has an analogue of the Casimir effect. For example, beads on a string as well as plates submerged in noisy water or gas illustrate the Casimir force.