## PROBLEMS

4/9/2013

Students should be given these problems to test their understading at the end of each lessons. The problems can ne taken as consolidation questions or homework. All problems are taken from PHYSICS 12, UNIVERSITY PREPARATION. The problems are arranged according to the lessons.
 www.Google.ca www.Google.ca LESSON 1 (Page 443)1.  A wave travels 0.3m in 3.5 s and has frequency of 4.6 Hz. Calculate the wavelength. 2.  Calculate the frequency of red light waves that have a wavelength of 750 nm. 3.  A wave on a string has  frequency of 0.83 Hz and a wavelength of 0.56 m. Determine the wavelength when a  new wave of frequency 0.45 Hz is established on this string and the wave speed  does not change.  LESSON 2 (Page 458) 1.  The speed of light in a  medium is measured to be 3.0 x 10^8 m/s.  Calculate the index of   refraction of the  medium. 2.  Light  travels through an optical fibre (n=1.44) to air. The angle of incidence of  light in the fibre is 30 degrees. Calculate the angle of refraction outside the  fibre.  LESSON 3 (Page 469) 1. Under what condition is the diffraction of waves  through a slit maximized? 2. Two speakers are 1.0 m apart and vibrate in phrase  to produce waves of wavelength 0.25 m. Determine the angle of the first nodal  line. 3.  What conditions are necessary for interference  pattern from a two-point source to be  stable?  LESSON 5 (Page  484) 1. When a monochromatic light source shines through a  double slit with a slit separation of 0.20 mm onto a screen 3.5 m away, the  first dark band in the pattern appears 9.1 mm from the centre of the bright  band. Calculate the wavelength of the  light. 2.  Two slits are separated by 0.30 mm and  produce an interference pattern. The fifth minimum is 12.8 x  10^-2 m from the central minimum. The wavelength of the light used is 4.5 x 10^-7  m. Determine the distance at which the screen is  placed. 3.  The second-order dark angle in a double-slit experiment is 5.4 degrees. Calculate  the ratio of the separation of the slits to the wavelength of the  light.  LESSON 6 (Page 511) 1. An extremely thin film of soapy water of  = 1.35 sits on top of a  flat glass plate of  =1.50. The soap film has a red colour when the incident light reflects perpendicularly off the surface of  the water. Determine the thickness of the film when  = 6.0 x 10 ^-7 m. 2. Use diagrams to explain why the top of a soap film  appears bright from one side and dark from the other when light is transmitted  through it.  LESSON 7 (page 519) 1.  Light with a wavelength of 794 nm produces a  single-slit diffraction pattern in which the ninth dark fringe lies at 6.48 cm  from the direction of the central maximum. Determine the width of the  slit. 2.  A slit of width 0.15 nm is located 10.0 m from a  screen. Light with a wavelength of 450 nm passes through this slit. Determine  the distance between the first and the third dark fringes on the  screen.  LESSON 8 (Page  525) 1. A diffraction grating has 2800 lines/cm. Determine the distance between two lines in the  grating. 2.  A square diffraction grating of width 2.0 cm  contains 6000 slits. At what angle does blue light with a wavelength 450 nm  produce the first intensity maximum? LESSON 9 (Page  531) 1. The light used in a CD player has a frequency of about 5.0 x  10 ^14 Hz. Determine its wavelength. 2.  The human eye is most sensitive to light with a  wavelength of about 550 nm. Calculate this light’s  frequency. 3. Some cordless telephones use radio waves with  frequency near 2.4 GHz to transmit to their base station. Calculate the  wavelength of these waves.  LESSON 10 (Page  537) 1. The sky often looks  very different when viewed through polarizing sunglasses. Explain what causes this effect. 2.  Using what you know,  explain why the sky appears blue.