13. Consider the following properties of light: I. rectilinear propagation II. reflection III. refraction IV. diffraction V. partial reflection-refraction Which of these properties did Huygens have trouble explaining with his theory of light? a. I only IV only I and IV only b. C. d. I and V only 14. Monochromatic light coming from the left passes through a slit S and then falls on a metal sheet with two slits B and C as shown below. The slits are the same width. The light then falls on a screen. B mm 5.0 m -10.0 m The intensity pattern shown below is centred at P. Intensity 3 0 3 Distance (cm) The wavelength of the light is closest to (a) 1.5 x 105 cm (b) 4.5 x 10-5 cm (e) 15 x 105 cm (c) 5.0 x 105 cm (d) 7.5 x 10-5 cm 15. 16. 17. Waves are produced by two point sources S and S vibrating in phase. P is a point on the third nodal line; the path difference SP - SP is 5.0 cm. S1 - OP The wavelength of the waves is (a) 1.4 cm (b) 1.7 cm (c) 2.0 cm (d) 2.5 cm (e) 3.3 cm A single slit is illuminated by parallel light and a diffraction pattern is formed on a screen some distance away. Which one of the following diagrams best represents the intensity distribution across the screen? (A) (B) (C) (D) " (E) Which one of the following is the correct unit for electrical potential difference? (a) A/s (b) W/J (c) J/C (d) C/s (e) J/A