Q17 of 26 Page 1

How are EM waves produced by oscillating charges?

Draw a sketch of linearly polarized EM waves propagating in the Z-direction. Indicate the directions of the oscillating electric and magnetic fields.


OR


Write Maxwell’s generalization of Ampere’s Circuital Law. Show that in the process of charging a capacitor, the current produced within the plates of the capacitor is



When the charge is in motion it produces both electrical and magnetic field due to the motion of the charged particle. Similarly an oscillating charge produces magnetic and electrical field which is oscillating in nature. When these oscillating fields are produces simultaneously they produce electromagnetic waves.


The sketch of linearly polarized EM waves propagating in the Z direction.


Indicate the directions of the oscillating electric and magnetic fields is


As the charge is oscillating so is the field as shown in the above diagram of Fig 17.1


OR


To write the Maxwell’s generalised equation of ampere circuital law



Therefore, the charging between the plates is given by



Now calculating the electrical flux ():



We get the final flux as



Hence, to find the rate of electrical change with respect to time we differentiate the formula, we get:



can be written as current I, we get



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