SEMMELWEIS UNIVERSITY Medical Biophysics I. Semifinal - Practice topics Questions With All Correct Answers!!

How does refractive power of a lens change if its radius of curvature decreases? - Answer-The power increases How does refractive power of a lens change if its radius of curvature increases? - Answer-The power decreases What is radius of curvature in case of a lens? - Answer-Flattener lens= larger radius of curvature. More rounded lens=lesser radius of curvature. How does refractive power of a lens change if its index of refraction increases? - Answer-Refractive power will increase Calculate the refractive power of a lens with a focal distance of 25 cm. - Answer-1/0.25=4 dpt Calculate the refractive power of a lens with a focal distance of 20 cm. - Answer-1/0.20=5 dpt Calculate the refractive power of a lens with a focal distance of 17 mm. - Answer-1/0.017=5.88 dpt Characterize the image of an object placed within the focal distance of a converging lens. - AnswerVirtual, magnified and upright Characterize the image of an object placed between the single and the double focal distance of a converging lens. - Answer-Real, magnified and inverted Characterize the image of an object placed outside the double focal distance of a converging lens. - Answer-Real, diminished and invertedWhat kind of image is formed by a compound light microscope? - Answer-Virtual, magnified and inverted What is the total magnification of a light microscope if the objective magnification is 100x and the ocular magnification is 20x? - Answer-100*20= 2000 Describe the steps of the eyepiece scale calibration process. - Aece scale is placed in the intermediate image plane (unknown units) a stage micrometer (with known units) as a ''specimen'' the eyepiece scale and the micrometer on one another late the calibration factor by dividing the known length of the stage micrometer by the number of rules of the eyepiece scale. What prisms are present in the Abbe-refractometer? - Answer-Illuminating prism (rough surface), measuring prism (flint glass with high index of refraction) and Amici prisms (restores dispersed light to white light or vise versa) What sample can be measured with the Abbe-refractometer? - Answer-Solutions with an index of refraction lower than that of the measuring prism (because we want snell's window) What is the role of Amici prism? - Answer-To restore dispersed light into white light (or vice versa) What is optical dispersion? - Answer-Phenomenon in which white light is decomposed into component colors due to the dependence of refractive index on frequency Factors influencing the value of index of refraction. - Answer-Solvent concentration in dilute solution, the frequency, temperature (makes fluids less viscous so light travels faster) Formation of Snell circle. - Answer-Grazing rays from lower index of refraction medium, refract at the boundary and make critical angles at the medium with the higher index of refraction, the critical angles form the borders of a cone of bright light. How do you determine concentration by refractometry? - Answer-In case of dilute solutions n1=n0+k*cWhat is the refractive index of distilled water? - Answer-1.33 Definition of absorption spectrum. - Answer-Absorbance as a function of wavelength. Unique to every element. What information can you obtain from an absorption spectrum? - Answer-Concentration of solutions (based on intensity change) and the electronic structure of the atom