PHYSICS 3LC MT EXAM QUESTIONS AND ANSWERS LATEST UPDATE

PHYSICS 3LC MT EXAM QUESTIONS AND ANSWERS LATEST UPDATE choose a property that describes the laser used in lab 2 a. laser beam did not diverge when it impinged on the wall b. laser beam travelled uniformly in all directions c. laser beam intensity decreased as 1/r^2 as the separation b/w laser and detector increased d. laser intensity did not vary as the detector was moved away e. spatial resolution of laser beam is not as good as the lamp in imaging an object - Answers d a prism was used to disperse the light into diff colors. Select the correct statement from below for spectrum of light observed from a desk lamp (incandescent light) and a discharge lamp (lab 4) a. both light sources gave continuous distribution of colors in the visible range b. both light sources gave line spectra of different colors c. desk lamp gave a line spectrum and discharge lamp gave continuous distribution of colors d. discharge lamp gave line spectrum and desk lamp gave continuous distribution of colors e. none - Answers d what's a collimated source? - Answers all particles emitted travel in same direction. NOT distant-dependent. ex: laser beam pew pew -- flux constant what's an isotropic source? - Answers emits particles uniformly in ALL DIRECTIONS. distant-dependent. ex: lamp -- flux DECREASE as displacement b/w light & photometer INCREASE. what's flux? - Answers # of photons that goes thru a 1cm volume of the sphere in a second. (more flux -- more INTENSITY) define principal axis - Answers imaginary line perpendicular to plane of lens bisecting lens where light ray passes UNREFRACTED which type of lens has a NEGATIVE focal length (concave/convex)? Why? - Answers concave. b/c the diffracted rays DON'T meet each other @ a focal point (they diverge). you have to extend the diffracted rays back -- makes a virtual image. What does it mean to have a negative focal length? - Answers the image is VIRTUAL. what's a virtual image? - Answers an image that isn't projected on the screen past the lens but is reflected(????) ish back and be seen by the naked eye. does concave or convex lens produce a negative lateral magnification (M) value? why? - Answers convex. because M = -i/o and i is POSITIVE for convex lens. what does it mean when lateral magnification (M) is less than 1? - Answers image is reduced. made smol. examples of real image? - Answers - image is focused onto screen - image is focused on paper example of virtual image? - Answers NO magnified image is seen on the screen through the lens. which lens (convex/concave) flip the image upside down? why? - Answers convex. lateral magnification is negative. In the experiment (Wk4), a camera is used to see the image on the screen past the lens. The camera must be focused beyond the plane of the magnifying lens to get a sharp magnified image. Why? - Answers the camera CAN'T focus on JUST the magnification lens to see the image because THAT'S NOT WHERE THE FOCAL POINT IS (where the rays converge) to see a clear image.