уровень

1. Arrange the given EM waves in order from low frequency to high frequency.

a). Radar waves, b). UV rays, c). Gamma rays, d). Radio waves, e). Infrared rays, f). X-Rays, g). Visible waves.

2. An airport radar system detects an unidentified flying object (UFO). What is the distance to the object if 100 μs passes between transmission and reception of radar signals?

3. The minimum Jupiter – Earth distance is 588,5 million km. How long does it take a radar signal sent from an observatory to return to earth after reflecting from Jupiter?

4. An EM wave has

V/m,

where c is the speed of light. Write the equation for the magnetic field wave. What is the frequency of the wave?

5. Тhe amplitude of electric field oscillations in a sinusoidal EM wave from a 2 MHz transmitter is 100 V/m. Write the equation for the instantaneous value of electric-field E(t)=? Assume plane waves travelling in the +x direction.

6. The electric field component of an EM wave is given by

V/m.

What are the frequency, wavelength and direction of propagation of the wave?

7. Electromagnetic waves travel in a homogeneous medium with a speed of 2∙10⁸ m/s. What is the wavelength of the waves in this medium, if the frequency in vacuum is 100 kHz?

8. A diffraction grating has 800 slits in 1 cm.

a) Find the slit spacing.

b) Find the wavelength of the light if the 3rd maximum is observed at an angle of 9º. (Sin 9º=0.156)

9. What is the difference between the phenomena of diffraction and interference. What is common to both?

10. In a double slit experiment one of the slits is covered with a thin transparent film. What changes occur in the interference pattern?

11. A diffraction grating has 100 slits in 1 mm. Find the distance between two successive slits.

12. Light of wavelength 680 nm is incident on a diffraction grating containing 125 lines/mm. Find the angular positions of the first and the third maxima.

13. In a diffraction grating two successive slits are 0.005 mm apart.

a) Find the number of silts in 1 mm

b) Find the distance from the central maximum to the second bright fringe on a screen 2 m away, if the wavelength of the light is 600 nm.

14. A laser pointer containing wavelengths between 635 nm and 670 nm is incident on a 500 slits/cm diffraction grating. How wide is the second order maximum on a screen 1 m away from the grating?

15. A monochromatic light of wavelength 650 nm is incident on a diffraction grating which has 5000 slits/cm. How many bright lines can be observed through the grating?

16. The number of bright lines which can be observed through a diffraction grating is 9. What is the maximum number of slits per centimetre for this grating if the wavelength of the light is 5000 Å?

17. A camera lens is coated with a film to reduce reflection from its surface. What is the minimum thickness required for the film not to reflect yellow-green light (to which the human eye is most sensitive) of wavelength 500 nm? (Take n_film = 1.38)

18. A film of oil of uniformly increasing thickness produces an interference pattern. The oil film (n = 1.42) is illuminated by a sodium lamp (λ = 589 nm). Find the difference in the thickness of two adjacent red fringes.

19. Find the frequency of a light wave of wavelength 4000Å.

20. The wavelength of a monochromatic light source in air is 591 nm.

a) What is the wavelength in glass (nglass=1.5)

b) Find the speed of light in glass

21. How do the speed, frequency, wavelength and direction of a light wave change when it passes from air into water?

22. A light wave has a wavelength of 600 nm in air and 400 nm in a medium. Find the index of refraction of the medium.

23. A monochromatic light of wavelength 6000 Å passes through two slits 0.3 mm apart and falls onto a screen placed 1 m away from the slits. Find

a) Fringe separation

b) Distance from the central line to the 2nd dark fringe

c) Distance from the central line to the 3rd bright fringe

24. In a double slit experiment the fringe separation is 2.5 mm. What is the new fringe separation if the distance to the screen from the slits is doubled and the slit separation is halved?

25. In a double slit experiment the distance between the 1st and 4th dark fringes on the same side is measured to be 7.5 mm. What is the distance from the 2nd bright fringe to the central line?