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Electromagnetic waves Book Back Questions

12th Standard

    Reg.No. :
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Physics

Time : 00:45:00 Hrs
Total Marks : 30
    3 x 2 = 6
  1. What is displacement current?

  2. What are electromagnetic waves?

  3. What is meant by Fraunhofer lines?

  4. 3 x 3 = 9
  5. The relative magnetic permeability of the medium is 2.5 and the relative electrical permittivity of the medium is 2.25. Compute the refractive index of the medium.

  6. Discuss briefly the experiment conducted by Hertz to produce and detect electromagnetic spectrum.

  7. Write down the properties of electromagnetic waves.

  8. 3 x 5 = 15
  9. A magnetron in a microwave oven emits electromagnetic waves (em waves) with frequency f = 2450 MHz. What magnetic field strength is required for electrons to move in circular paths with this frequency?

  10. A pulse of light of duration 10−6 s is absorbed completely by a small object initially at rest. If the power of the pulse is 60\(\times\) 10−3 W. Calculate the final momentum of the object.

  11. If the relative permeability and relative permittivity of a medium are 1.0 and 2.25 respectively, find the speed of the electromagnetic wave in this medium.

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