射电天文基础
... Homework (cont’d) • Apply the Stefan-Boltzman relation to the Sun and the planets to estimate the surface temperature if each planet is assumed to absorb all of the radiation it receives (this is an albedo of zero – this is the upper limit the planet can absorb since in reality some radiation is re ...
... Homework (cont’d) • Apply the Stefan-Boltzman relation to the Sun and the planets to estimate the surface temperature if each planet is assumed to absorb all of the radiation it receives (this is an albedo of zero – this is the upper limit the planet can absorb since in reality some radiation is re ...
Electromagnetic Fields and Waves
... The Lenz’s law states that, the induced current in the loop is always in such a direction as to produce flux opposing the change in flux density. 4. Explain briefly the different types of emf’s produced in a conductor placed in a magnetic field. There are two ways in which we can induce emf in a con ...
... The Lenz’s law states that, the induced current in the loop is always in such a direction as to produce flux opposing the change in flux density. 4. Explain briefly the different types of emf’s produced in a conductor placed in a magnetic field. There are two ways in which we can induce emf in a con ...
Semester II
... Applications of Gauss theoremElectric field due to point charge, infinite line of charge, uniformly charged spherical shell and solid sphere, plane charged sheet, charged conductor. Electric potential as line integral of electric field, potential due to a point charge, electric dipole, uniformly cha ...
... Applications of Gauss theoremElectric field due to point charge, infinite line of charge, uniformly charged spherical shell and solid sphere, plane charged sheet, charged conductor. Electric potential as line integral of electric field, potential due to a point charge, electric dipole, uniformly cha ...
Presentazione di PowerPoint
... These expressions have been derived in the near field limit (r << l). Let’s notice that they are exactly the same expressions known for the fields due to static electric and magnetic dipoles. So if we calculate the Poynting vector of these fields we obtain exactly zero because they don’t carry out e ...
... These expressions have been derived in the near field limit (r << l). Let’s notice that they are exactly the same expressions known for the fields due to static electric and magnetic dipoles. So if we calculate the Poynting vector of these fields we obtain exactly zero because they don’t carry out e ...
LIGHT AND COLOR
... • Spatial variation of the electric field is equal to the temperal variation of the magnetic field. • Spactial variation of the magnetic field is equal to the temperal variation of the electric field • The divergence of the magnetic field is zero (no magnetic poles) • The divergence of the electric ...
... • Spatial variation of the electric field is equal to the temperal variation of the magnetic field. • Spactial variation of the magnetic field is equal to the temperal variation of the electric field • The divergence of the magnetic field is zero (no magnetic poles) • The divergence of the electric ...
Reilly
... However, this leads to a large external and dipolar magnetic fields which will tend to demagnetize the material. Domains are formed to minimize this effect. ...
... However, this leads to a large external and dipolar magnetic fields which will tend to demagnetize the material. Domains are formed to minimize this effect. ...
Lesson Sheet
... Many of the greatest scientific discoveries have been lucky accidents. Electromagnetism was one of those. During a lecture in the year 1819, Hans Oersted had a compass sitting next to a wire. When Oersted completed the circuit by connecting the wire to a battery, the direction that the needle was po ...
... Many of the greatest scientific discoveries have been lucky accidents. Electromagnetism was one of those. During a lecture in the year 1819, Hans Oersted had a compass sitting next to a wire. When Oersted completed the circuit by connecting the wire to a battery, the direction that the needle was po ...
Exercise 4
... until the middle of the 19th century, physicists widely believed that EM waves could exist in a vacuum. Further, they did not connect EM waves to light, even though some of them suspected that there would be a connection. The magnetic field of a coil of current-carrying wire Equipment needed: a coil ...
... until the middle of the 19th century, physicists widely believed that EM waves could exist in a vacuum. Further, they did not connect EM waves to light, even though some of them suspected that there would be a connection. The magnetic field of a coil of current-carrying wire Equipment needed: a coil ...
Magnetohydrodynamics
Magnetohydrodynamics (MHD) (magneto fluid dynamics or hydromagnetics) is the study of the magnetic properties of electrically conducting fluids. Examples of such magneto-fluids include plasmas, liquid metals, and salt water or electrolytes. The word magnetohydrodynamics (MHD) is derived from magneto- meaning magnetic field, hydro- meaning water, and -dynamics meaning movement. The field of MHD was initiated by Hannes Alfvén, for which he received the Nobel Prize in Physics in 1970.The fundamental concept behind MHD is that magnetic fields can induce currents in a moving conductive fluid, which in turn polarizes the fluid and reciprocally changes the magnetic field itself. The set of equations that describe MHD are a combination of the Navier-Stokes equations of fluid dynamics and Maxwell's equations of electromagnetism. These differential equations must be solved simultaneously, either analytically or numerically.