New ! Physics MCQ Practise Tests



Electromagnetic Waves Model Question Paper 1

12th Standard

    Reg.No. :
  •  
  •  
  •  
  •  
  •  
  •  

Physics

Time : 01:00:00 Hrs
Total Marks : 50
    5 x 1 = 5
  1. In an electromagnetic wave traveling in free space the rms value of the electric field is 3 V m−1. The peak value of the magnetic field is _____.

    (a)

    1.414 x 10-8 T

    (b)

    1.0 x 10-8 T

    (c)

    2.828 x 10-8 T

    (d)

    2.0 x 10-8 T

  2. During the propagation of electromagnetic waves in a medium __________________.

    (a)

    electric energy density is double of the magnetic energy density

    (b)

    electric energy density is half of the magnetic energy density

    (c)

    electric energy density is equal to the magnetic energy density

    (d)

    both electric and magnetic energy densities are zero

  3. If E = Eo sin[106 x -ωt] be the electric field of a plane electromagnetic wave, the value of ω is_____.

    (a)

    0.3 x 10−14 rad s−1

    (b)

    3 x 10−14 rad s−1

    (c)

    0.3 x 1014 rad s−1

    (d)

    3 x 1014 rad s-1

  4. Which of the following electromagnetic waves has the highest frequency?

    (a)

    radio waves

    (b)

    micro waves

    (c)

    X- rays

    (d)

    ૪-rays

  5. Which of the following E.M waves has the longest wavelength?

    (a)

    Radio waves

    (b)

    IR

    (c)

    X-rays

    (d)

    visible

  6. 5 x 2 = 10
  7. What is displacement current?

  8. Write down the integral form of modified Ampere’s circuital law.

  9. What is meant by Fraunhofer lines?

  10. Write the uses of Micro waves.

  11. (i) How is the speed of Electromagnetic waves in vacuum determined by the electric and magnetic fields? and
    (ii) Do Electromagnetic waves carry energy and momentum?

  12. 5 x 3 = 15
  13. Explain the Maxwell’s modification of Ampere’s circuital law.

  14. Explain the types of absorption spectrum.

  15. Write the production of gamma rays and mention its properties and uses.

  16. The charge on a parallel plate capacitor varies as q = qo cos 2\(\pi \gamma \)t. The plates are very large and close together. (area - A. separation - d) find the displacement current through the capacitor?

  17. Identify the following Electromagnetic radiations
    (a) 109 Hz
    (b) 1011 Hz. Give one application of each.

  18. 4 x 5 = 20
  19. A transmitter consists of LC circuit with an inductance of 1 µH and a capacitance of 1 µF. What is the wavelength of the electromagnetic waves it emits?

  20. 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.

  21. In an electric circuit, there is a capacitor of reactance 100 Ω connected across the source of 220 V, find the displacement current.

  22. In which way you can establish an instantaneous displacement current of 1.0 A in the space between the parallel plates of 1μf capacitor?

*****************************************

Reviews & Comments about 12th Physics - Electromagnetic Waves Model Question Paper 1

Write your Comment