7. The interference pattern created by monochromatic light in an air wedge is used to measure the thickness of an object. Which of the following changes would cause the spacing between adjacent fringes to increase? a. Use a light source with a higher frequency. b . Increase the thickness of the object being measured. Use a light source with a longer wavelength Use a shorter air wedge. e . None of the above. 8. The diagram above shows a single slit with lines marking the direction to a point P in the diffraction pattern generated. X and Y are the edges of the slit. The possible value for the path difference, PY - PX, that places P at the first intensity minimum adjacent to the central maximum is d. 21 2 52 b. 2 32 2 9. Anti-glare coatings on most lenses appears to have a purplish tint. This is due to the fact that a. it is difficult to manufacture a coating thin enough to absorb the violet glare b. most coatings are chosen with a thickness that corresponds to eliminating the glare in the middle of the visible spectrum C . the material used for the coatings contains pigments which have a purple tint our eyes are most sensitive to this region of the visible spectrum e . the blue light scattered through the atmosphere has the brightest intensity when it strikes the coating 10. What is the wavelength of a radio wave (travelling at 3.00 x 10 $m/s) from a local radio station that broadcasts at 1050 kHz? a. 286 km d. 286 m b. 1.05 x 103 m e. 0.286 m C. 572 m Short Answer - Neatly provide written responses [10 marks] 11, Digital images consist of pixels, or small coloured dots. If an image is 84 pixels wide by 62 pixels high, explain how could you achieve a better resolution without using more pixels per square cm. [2 marks]