CBSE Class 12 Physics Electromagnetic Waves Frequently Asked Questions

CBSE Class 12 Physics Electromagnetic Waves Frequently Asked Questions. There are many more useful educational material which the students can download in pdf format and use them for studies. Study material like concept maps, important and sure shot question banks, quick to learn flash cards, flow charts, mind maps, teacher notes, important formulas, past examinations question bank, important concepts taught by teachers. Students can download these useful educational material free and use them to get better marks in examinations.  Also refer to other worksheets for the same chapter and other subjects too. Use them for better understanding of the subjects.

ELECTROMAGNETIC WAVES

1. A plane monochromatic light wave lies in the visible region. It is represented by sinusoidal variation with time by the following components of electric field:

E_x = 0₁, E_y = 4 sin [2π/λ (x – Vt)], Ez = 0 X Y Where, v (freq) = 5 x 10¹⁴ H₂ and n is velocity. z

(i) What is the direction of propagation of the wave?

(ii) What is its amplitude? And

(iii) Compute the components of magnetic field.

2. Give two characteristics of electromagnetic waves. Write the expression for the velocity of electromagnetic waves in terms of permittivity and magnetic permeability of free space.

 3. Find wavelength of electromagnetic waves of frequency 5 x 10¹⁹ H_z in free space. Give its two applications.

4. Name the characteristics of e. m. waves that: (i) increases, & (ii) remains constant in e. m. spectrum as one moves from radiowave region towards ultraviolet region.

5. Which constituent radiation of electromagnetic spectrum is used: (i) in radar? (ii) To photograph internal parts of human body? & (iii) for taking photographs of the sky during

night and foggy condition? Give one reason for your answer in each case.

6. Write any four characteristics of e. m. waves. Give two uses of: (i) Radio waves & (ii) Microwaves.

7. Name the following constituent radiations of e. m. spectrum which, (i) produce intense heating effect? (ii) is absorbed by the ozone layer, &(iii) is used for studying crystal structure.

8. Experimental observations have shown: (i) that X-rays travel in vacuum with a speed of 3 x 10⁸ m s^-1, & (ii) the phenomenon of diffraction and can be polarized. What conclusion is drawn about the nature of X-rays from each of these observations?

9. Why are infrared radiations referred to as heat waves? Name the radiations which are next to these radiations in e. m. spectrum having: (i) shorter wavelength, & (ii) longer wavelength.

10. The oscillating magnetic field in a plane electromagnetic wave is given by: B_y = 8 x 10^-6 sin [2 x 10¹¹ t + 300 π x] T 

(i) Calculate the wavelength of the electromagnetic wave &

(ii) Write down the expression for oscillating electric filed.

11. Identify the following electromagnetic radiation as per the wavelengths given below: (a) 10^-3 nm, & (b) 10^-3 m, & (c) 1 nm; Write one application of each.

12. Name the constituent radiation of electromagnetic spectrum which

(a) is used in satellite communication.

(b) is used for studying crystal structure.

(c) is similar to the radiations emitted during decay of radioactive nuclei.

(d) has its wavelength range between 390 nm and 770 nm.

(e) is absorbed from sunlight by ozone layer.

(f) produces intense heating effect.

13. What is meant by the transverse nature of electromagnetic waves? Drawdiagram showing the propagation of the an electromagnetic wave along X direction, indicating clearly the directions of oscillating electric and magnetic fields associated with it.

Please click the link below to download CBSE Class 12 Physics Electromagnetic Waves Frequently Asked Questions.