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The equivalence of mass and energy expressed by the relation E = mc 2 is a fairly direct consequence of Maxwell’s conception of electromagnetic waves. According to Maxwell’s equations, the energy density of electric and magnetic fields e and b is (e 2 + b 2 )/(8 p ) and the momentum density is ( e x b )/(4 p c). Thus in the case of radiation (when e and b are equal and orthogonal) the energy density is E = e 2 /(4 p ) and the momentum density is p = e 2 /(4 p c), so we have the important relation p = E/c. In addition, the energy of a pulse of light for relatively moving systems of reference transforms in proportion to its frequency, consistent with Planck’s relation E = h n . Given these facts, we can show that light pulses of total energy E reflecting inside a closed container contribute E/c 2 to the inertial mass (i.e., the resistance to acceleration) of the container. this one I got from a site. Here it states that, electric field=magnetic field(for light) But in the ncert physics of class 12 and many other sites it is given that E/c=B E=electric field B=Magnetic field c=speed of light So, which is correct


The equivalence of mass and energy expressed by the relation E = mc2 is a fairly direct consequence of Maxwell’s conception of electromagnetic waves. According to Maxwell’s equations, the energy density of electric and magnetic fields e and b is (e2 + b2)/(8p) and the momentum density is (e x b)/(4pc). Thus in the case of radiation (when e and b are equal and orthogonal) the energy density is E = e2/(4p) and the momentum density is p = e2/(4pc), so we have the important relation p = E/c. In addition, the energy of a pulse of light for relatively moving systems of reference transforms in proportion to its frequency, consistent with Planck’s relation E = hn. Given these facts, we can show that light pulses of total energy E reflecting inside a closed container contribute E/c2 to the inertial mass (i.e., the resistance to acceleration) of the container.




 


this one I got from a site.


Here it states that, electric field=magnetic field(for light)

 


But in the ncert physics of class 12 and many other sites it is given that


E/c=B


E=electric field


B=Magnetic field


c=speed of light


So, which is correct


 


Grade:upto college level

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