Biophysics Official Past Paper PDF

Министерство образования и науки Кыргызской Республики Ошский государственный университет Международный медицинский факультет Кафедра естественных наук и математики **«Утверждено» «Согласовано»** на заседании кафедры ЕНМ председатель УМС ММФ прот. №\_\_\_\_от \_\_\_\_\_\_2025г. к.э.н., доц. А....

Министерство образования и науки Кыргызской Республики Ошский государственный университет Международный медицинский факультет Кафедра естественных наук и математики **«Утверждено» «Согласовано»** на заседании кафедры ЕНМ председатель УМС ММФ прот. №\_\_\_\_от \_\_\_\_\_\_2025г. к.э.н., доц. А.М.Базиева зав. каф. А.Ы.Курбаналиев\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Фонд тестовых заданий предназначен для контроля знаний студентов направления 560001 «Лечебное дело GM» по дисциплине «Медицинская биофизика» на 2024-2025 учебный год Курс -1 Сетка часов по учебному плану +--------+--------+--------+--------+--------+--------+--------+--------+ | Наимен | Всего | Ауд. | Аудит. | СРС | Отчетн | | | |. | | зан. | зан. | | ость | | | | | | | | | | | | | дисцип | | | | | | | | | -лины, | | | | | | | | | семест | | | | | | | | | р | | | | | | | | +========+========+========+========+========+========+========+========+ | | | | лекции | лаб. | | 1,2сем | 1,2 | | | | | | | |. | сем. | +--------+--------+--------+--------+--------+--------+--------+--------+ | Мед. | 120ч | 48ч | 20ч | 28ч | 72ч | РК-2 | Экз. | | | | | | | | | | | биофиз | (4кр) | | | | | | | | ика | | | | | | | | +--------+--------+--------+--------+--------+--------+--------+--------+ | 1,2сем | 120 | 48 | 20 | 28 | 72 | РК-2 | Экз. | |. | | | | | | | | +--------+--------+--------+--------+--------+--------+--------+--------+ Составили: д. ф-м.н., проф. Курбаналиев А.Ы., к.п.н., доц. Алиева Ч.М., к.ф-м.н., ст.преп. Баатыров Р.Т. Ош- 2025 г. 1\. For what all purposes is diathermy principal used? a\) Surgical and Therapeutic b\) Therapeutic and Diagnostic c\) Diagnostic and surgical d\) Diagnostic and rehabilitative 2.What surgical functions are performed by the diathermy machine? a\) cutting, coagulation, fulguration b\) cutting, fulguration c\) cutting, coagulation d\) coagulation, fulguration 3\. The types of therapeutic diathermy machines that exist are \_\_\_\_\_\_\_\_\_\_\_ a\) Short wave, micro wave and ultrasound b\) Short wave, ultrasound and cold compress c\) Cold compress, microwave and electrical impulse d\) Electrical impulse, microwave and ultrasound 4\. Which of the diathermy machine is good for deep tissue healing? a\) short wave b)ultrasound\ c) cold compress d\) electrical impulse 5\. What is the frequency range of the sound used for ultrasound diathermy? a\) 0.1 -- 0.7 MHz b\) 0.7 -- 3.3 MHz c\) 3.3 -- 5 MHz d\) 5 -- 15 MHz 6\. What precaution is used in diathermy? a\) the patient is made to lie on a soft pillow b\) pads are used for grounding and completing the circuit c\) the patient is made to drink a large number of fluids d\) wooden blocks are used for grounding 7\. In heat wave diathermy, the maximum power given out is 500 W and the maximum voltage possible is 4000V. Thus, what is the highest resistance that heat wave diathermy machine can deal with? a\) 3.2 K ohm b\) 32 K ohm c\) 320 K ohm d\) 3200 K ohm 8\. Which of the following is used to measure the biological damage caused by radiation? a\) Curie b\) Rem c\) Rad d\) Roentgens 9\. Beyond what dose is the cerebral system shows signs of failure? a\) 25 -- 200 rad b\) 200 -- 600 rad c\) 600 -- 1000 rad d\) \> 1000 rad 10\. What is the relation between 1 Rad, 1 Rem and 1 R? a\) 1 Rad ≈ 1.5 Rem ≈ 1000 R b\) 1 Rad ≈ 10 Rem ≈ 1.8 R c\) 1 Rad ≈ 1 Rem ≈ 1 R d\) 1 Rad ≈ 10 Rem ≈ 100 R 11\. The two known units of radioactivity and the relation between the two are \_\_\_\_\_\_\_ a\) Curie and Becquerel 1 Ci = 3.7 x 1010 Bq b\) Curie and Becquerel 1 Bq = 3.7 x 1010 Ci c\) Curie and Roentgens 1 Ci = 1000 R d\) Roentgen and Becquerel 1 R = 1000 Bq 12\. In a hypothetical radioactive material, the total number of active photons are 20000 and the decay constant is found out to be 4.916 X 10^-17^ per second. How much of the material will be left in a 100 years? (1 year = 365 days. Leap year is not assumed in the calculations) a\) 1589.99999 b\) 19,999.9999 c\) 19.999999 d\) 123.99999 13\. If the half life is found to be 100 msec, what is the decay constant? a\) 693 per second b\) 24948 per hour c\) 0.1155 per minute d\) 59875.2 per day 14\. With what energy must the radiation be given to image a bone of thickness 5 cm which has covering of skin of thickness of 2 cm on the both sides and the emerging intensity of the X -- Ray is 200MeV. (impedance for bone = b for skin = s ) a\) 2000e^9^ b\) 200e^(4s\ +\ 5b)^ c\) 20/e d\) 2e 15\. In the induction field diathermy, the heating effects are done by a\) Using magnetic field b\) Induce an electrical current within body parts c\) Using an electric field d\) Made of metal that is shaped into a coil 16\. A low dielectric constant & conductivity is to a\) High water content, muscle nerve, blood vessels, internal organs & moist skin b\) Low water content, bone, capsule, ligaments, fat, dry skin c\) All of the above 17\. A high dielectric constant & conductivity is to a\) High water content, muscle nerve, blood vessels, internal organs & moist skin b\) Low water content, bone, capsule, ligaments, fat, dry skin c\) All of the above 18\. The electric field will a\) Converge onto substance with high dielectric constant b\) Converge onto substance with low dielectric constant c\) Diverge within substances with high dielectric constant d\) Diverge within substances with low dielectric constant 19\. The process of destroying cancer cells with the help of radiation is \_\_\_\_\_\_\_\_ a\) radiotherapy b\) physiotherapy c\) uroplasty d\) rehabilitation 20\. Which of the following pair of scattering is important for diagnostic purposes? a\) Coherent and Compton b\) Photoelectric and Pair Production c\) Compton and Photoelectric d\) Pair Production and Disintegration 21.Which technique separates charged particles using electric field? a\) Hydrolysis b)Electrophoresis\ c) Protein synthesis d\) Protein denaturing 22\. Electrophoresis was developed by: a\) Tswett b)Tsvedberg\ c) Tiselius d\) Sanger 23.The speed of migration of ions in electric field depends upon: a\) Shape and size of molecule b\) Magnitude of charge and shape of molecule c\) Magnitude of charge shape and mass of molecule d\) Magnitude of charge and mass of molecule 24.Which of the following statements is true about migration of biomolecules? a\) The rate of migration is directly proportional to the resistance of medium b\) Rate of migration is directly proportional to current c\) Low voltage is used for separation of high mass molecules d\) Rate of migration is inversely proportional to current 25.What does the electrophoresis apparatus consist of? a\) Gel, buffer chamber and fire pack b\) Buffer chamber and electrophoresis unit c\) Electrophoresis unit and gel separator d\) Power pack and electrophoresis unit 26.If proteins are separated according to their electrophoretic mobility then the type of electrophoresis is: a\) SDS PAGE b\) Affinity Electrophoresis c\) Electro focusing d\) Free flow electrophoresis 27.The electrophoretic mobility denoted as µ is mathematically expressed as: a\) VE b)E/V\ c) 1/EV d\) V/E 28.Which of the following factors does not influence electrophoretic mobility? a\) Molecular weight b\) Shape of molecule c\) Size of molecule d\) Stereochemistry of molecule 29\. When is electrophoresis not used? a\) Separation of proteins b\) Separation of amino acids c\) Separation of Lipids d\) Separation of nucleic acids 30\. What cannot be a reason for using electrophoresis? a\) Comparing two sets of DNA b\) Organizing DNA by shape of backbone c\) Organizing DNA fragments from largest to smallest d\) Organizing DNA in order we can see **31. In electrophoresis, DNA will migrate towards** a\) cathode or positive electrode b\) anode or negative electrode c\) cathode or negative electrode d\) anode or positive electrode **32. The speed of migration of ions in an electric field depends on** a\) magnitude of charge and mass of molecules b\) magnitude of charge and shape of molecules c\)  shape and size of the molecule d\) magnitude of charge, shape and mass of molecules **33. Which of the following statement is true regarding migration of bio molecules?** a\) the rate of migration is directly proportional to the current b\) the rate of migration is inversely proportional to current c\) the rate of migration is directly proportional to the resistance of the medium d\) Low voltage is used for the separation of high molecular weight compounds **34. The most common type of gel used for DNA separation is** a\) Agar b\) Polyacrylamide c\) Agarose d\) All of the above **35. Which is the technique suited for the separation of large DNA fragments** a\) AGE b\) PAGE c\) PFGE d\) SDS-PAGE **36. What is the role of SDS in SDS-PAGE?** a\) protein denaturing and imparting net negative charge b\) imparting overall negative charge to the protein c\) imparting equal mass to all proteins d\)  protein unfolding and imparting net positive charge **37. In SDS-PAGE, separation is based on** a\) molecular weight b\) shape c\) charge d\) all of the above **38. The electrophoresis technique that used isoelectric focusing is** a\) AGE b\) PFGE c\) 2D-PAGE d\) SDS-PAGE 39\. In agarose gel electrophoresis, DNA is moved towards the a\) cathode b\) anode c\) DNA doesn\'t move d\) Moves slowly 40. A technique which separates charged particles using electric field is a\) Hydrolysis b\) electrophoresis c\) protein synthesis d\) protein denaturing 41. Sounds of frequency higher than 20,000 Hz which are inaudible to normal human ear are called a\) noise b\) frequency c\) ultrasonics d\) amplitude 42\. SONAR is abbreviation of a\) small navigation and random b\) sky navigation and ranging c\) sun nuclear ranging d\) sound navigation and ranging 43. A ship sends ultrasound that returns from seabed and is detected after 3.42 s. If speed of ultrasound through seawater is 1300 ms^-1,\ then\ distance\ of\ seabed\ from\ ship\ would\ be^ a\) 3000 m b\) 2600 m c\) 2200 m d\) 2800 m 44. Ultrasonic waves carry more a\) energy b\) frequency c\) heat d\) both frequency and energy 45. Wavelength of ultrasonic waves is a\) more than audible sound b\) less than audible sound c\) equal to audible sound d\) greater than light wave 46.Ultrasound is also useful for \_\_\_\_\_\_\_\_\_\_\ i. detecting fault in metal sheets ii. imaging marine depths iii. looking for metals beneath the earth's surface iv. detecting distances v. detecting earthquakes a\) ii, iii, v b\) i, iv, v c\) i, ii, iv d\) ii, iii 47\. What property of sound waves acts like the principle of ultrasound? a\) Reflection and Refraction b\) Reflection only c\) Refraction only d\) Propagation 48\. Which of the following medical imaging modality other than ultrasound does not use any form of radiation? a\) PET Scan b\) SPECT Scan c\) CT Scan d\) MRI 49\. For which of these areas can the ultrasound be taken for an infant but not for an adult? a\) Cranium b\) Chest c\) Arms d\) Legs 50\.  A piezoelectric crystal is used to produce the ultrasound waves. What kind of ultrasound is produced? a\) Pressure wave ultrasound b\) Electrical wave ultrasound c\) Sound wave ultrasound d\) Simple ultrasound 51. How is a medium characterized? a\) By its thickness b\) By its acoustic impedance c\) By its water content d\) By its density 52\. The wave velocity of ultrasound in soft tissues is 1540m/s and the impedance offered by it is 1.63 X 106 kg/m^2^s. What is the density of the soft tissue? a\) 0.1058441 kg/m^3^ b\) 10.58441 kg/m^3^ c\) 1058.441kg/m^3^ d\) 105844.1 kg/m^3^ 53\. Which of the following relations are true? a\) γ increases, penetration of sound increases, resolution decreases b\) γ increases, penetration of sound decreases, resolution decreases c\) γ increases, penetration of sound decreases, resolution increases d\) γ decreases, penetration of sound increases, resolution increases 54\. When an abdominal ultrasound is done, why is it advised to have a full bladder? a\) To have a good acoustic window b\) To increase the water content c\) To lower impedance d\) To allow for better propagation of waves 55\. What does the red dot on the probe help within the produced image? a\) To check if the correct probe was used b\) To check the probe orientation c\) To check the depth of the probe that was used d\) To check the plane of the image. 56\. The rate at which an ultrasound pulse is absorbed (attenuated) as it passes through tissue is affected by:  a) The pulse amplitude.  b) The pulse intensity.  c) The pulse frequency.  d) Characteristics of the tissue. 57.The parameters spatial-peak, temporal-average, and pulse-average must be considered when expressing values for ultrasound:  a) Intensity.  b) Absorption. c\) Velocity.  d) Pulse rate 58.The lowest rate of ultrasound absorption occurs in:  a) Fat  b) Air  c) Bone.  d) Lung. 59\. The principal advantage of an annular-array transducer is that it provides:  a) Faster imaging.  b) Better penetration.  c) Variable frequency.  d) Variable focal depth. 60.One or more ghost-images of a body structure displayed at different depths within an ultrasound image are signs of: a\) Shadowing. b\) Reverberation. c\) Refraction. d\) Enhancement. 61.The \'filter\' in filtered backprojection refers to a\) Bowtie filter between the beam and patient b) Conversion between attenuation and Hounsfield units c\) Conversion between fan-beam and parallel geometry d\) Fix for the blurring inherent to backprojection 62\. Changing filters (aka kernels) in filtered backprojection results in a\) Trade-off between image sharpness and noise b\) Different window levels in CT images c\) Different patient dose d\) Different reconstructed field of view (FOV) 63\. The main advantage of iterative reconstruction techniques versus filtered backprojection is a\) Better depiction of bone detail b\) Does not require specification of reconstruction kernel or filter c\) Better handling of noisy images d\) Faster reconstruction 64\. In helical CT, a single transverse slice represents a\) A plane through the body perpendicular to the scan axis b\) A plane through the body oblique to the scan axis c\) A reconstruction made from projections at neighboring scan axis positions 65\. In helical CT, pitch is defined as a\) Table movement in 360 degrees / beam width b\)  Patient dose in 360 degrees / beam width c\) Reconstructed slice thickness / beam width d\) Gantry angle with respect to the scan axis 66\. High-pitch techniques are useful for a\) Very small findings (e.g. nondisplaced fracture) b\) Gated cardiac CT c\) Accurate multiplanar reconstructions d\) Fast scans 67\. In helical CT, a low-pitch technique might be most helpful for a\) Scanning a tachypneic patient b\) Detecting a non-displaced fracture c\) Detecting a subtle liver lesion d\) Scanning a young child 68.Which of the following numbers reported by the scanner best reflects the *total amount* of radiation delivered to the patient  a) Dose b\) Pitch c\) Dose-length product (DLP) d\) Effective mAs 69.The following term refers to a measure designed to reflect stochastic (cancer) risk from radiation a\) Dose b)Average dose c\) Effective dose d\) Dose-length product (DLP) 70\. Deterministic effects in CT would best be measured by looking at a\) CT Dose Index (CTDI) b\) Dose-length product (DLP) c\) Effective dose d\) Pitch 71\. Dose in CT can be reduced by which of the following parameter adjustments (assuming other factors constant): a\) Increasing kV b\) Increasing mAs c\) Increasing Pitch d\) Increasing scan length 72\. How is radiation dose distributed in the patient\'s body in CT? a\) Mostly at the skin surface b\) Mostly in the center of the body c\) More at the skin surface than in the center d\) Entirely uniformly from the skin to the center of the body 73\. With the same CTDI (i.e. same scan parameters), what happens to radiation dose with changing the patient size? a\) Increasing patient size causes increased dose b\) Increasing patient size causes decreased dose c\) Increasing patient size does not change dose 74\. The dose parameter used to correct CTDI for patient size is the a\) Effective dose b\) Dose-area product (DAP) c\) Size-specific dose estimate (SSDE) d\) CTDI Volume (CTDIvol) 75\. Positioning the patient off-center within the CT gantry will result in a\) Decreased dose b\) Increased dose c\) Reconstruction artifacts d\)  Incorrect Hounsfield unit numbers 76\. Decreasing kV in CT is advantageous because a\) X-ray penetration improves b\) Tissue contrast improves c\) Scan times are reduced d\) Metal streak artifacts are improved 77\. Automated exposure compensation uses the topogram (or scout) image to determine a\) Tube current (mA) b\) Pitch c\) Reconstruction filter d\) Bowtie filter 78\. The goal of automated exposure compensation is a\) To generate images of similar noise in different patient sizes b\) To scan patients of different sizes with the same kV and mAs settings c\) To obtain pretty, low-noise images d\) To eliminate the radiation risks from CT examinations 79\. The major technical challenge in cardiac CT is a\) Spatial resolution b\) Temporal resolution c\) Contrast resolution d\) Three-dimensional reconstruction 80\. The major determinant of temporal resolution in CT is a\) Gantry rotation speed b\) Reconstruction algorithm c\) Fan-beam angle d\) Detector collimation e\) Computer processing power 81\. One small square on an EKG is equivalent to how much time (and what distance)? a\) 0.04 sec (2mm) b\) 0.20 sec (1mm) c\) 0.04 sec (1mm) d\) 0.01 sec (1mm) 82\. One large square is equal to what amount of time (and distance) on EKG? a\) 2 sec/.5mm b\) 20 sec/5 mm c\) 0.02 sec/0.5mm d\) 0.2 sec/5mm 83\. What leads are considered inferior leads? a\) II, III, aVF b\) II, III, aVR c\) I,II,III d\) V1,II 84\. What leads are considered (left) lateral leads? a\) I aVR b\) I, aVL c\) V5,V6 d\) II,III 85\. Choose the correct placement of V1 : a\) 5th right intercostal space b\) V2 c\) 4th right intercostal space d\) Where the sun don\'t shine 86\. Name the correct placement of V2: a\) 4th left intercostal space b\) 4th right intercostal space c\) 5th left intercostal space d\) 5th right intercostal space 87\. Name the placement for V4 a\) 4th left intercostal space b\) 5th intercostal space, anterior axillary line c\) 5th intercostal space, midclavicular line d\) 5th intercostal space midaxillary line 88\. Please choose the lead placement for V5/V6 9.What view of the heart does V1-V4 give ? a\) Anterior b\) Posterior c\) Lateral 89\. What view of the heart does V5-V6 give ? a\) Left lateral view b\) Right lateral view c\) Mid axillary view 90\. In which lead is the P wave best seen? a\) II b\) III c\) AvF d\) V1 91\. In which leads would you see a positive P wave? a\) I, II, III b\) AVL, AVF, V4-V6 c\) V4-V6 d\) I, II, AVL, AVF, V4-V6 92\. In which lead would you see a BIPHASIC P wave? a\) V2-V3 b\) V5-V6 c\) V1 d\) V3 93\. Regarding the QRS complex: In which leads would you see a Deep S wave ? a\) V1 b\) V1, V2 c\) V3, v4 d\) V5,v6 94\. Regarding the QRS complex: In which lead(s) would you see a TALL R wave? a\) V5 b\) V6 c\) V1,V2 d\) V5,V6 95\. Regarding the QRS complex: In which lead(s) would you see a biphasic complex, reflection a \"transition zone\"? a\) V1,V2 b\) V2,V3 c\) V3, V4 d\) V4,V5 96\. In what leads do you see an \"R wave progression\"? a\) V1 to v6 b\) V2 to v4 c\) V5 to v6 d\) V1 to v4 97.What part of the EKG is known as the \"plateau phase\", and represents the initial part of ventricular repolarization? a\) S Wave b\) ST Segment c\) PR interval 98\. What segment, if elevated or depressed, reveals a sign of serious pathology? a\) ST b)PR c\) R-R d\) QT 99.What wave represents ventricular repolarization? a\) U wave b\) P wave c\) Q wave d\) T wave 100\. Which of the following best represents the normal height of the T WAVE? a\) 1/2-2/3 height of corresponding R wave b\) 1/3-2/3 height of corresponding R wave c\) 1/3-2/3 height of corresponding T wave d\) 1/2-2/3 height of corresponding T wave 101\. What portion of the EKG represents the duration of ventricular systole? a\) QT interval b\) PR segment c\) QRS complex d\) ST segment 102.The QT interval varies with heart rate, and thus must be corrected. This corrected QT interval is also abbreviated as (QTc). This value is considered normal when it\'s less than half of the \_\_\_\_\_ interval at normal rates. a\) P-R b\) Q-R c\) R-R d\) P-P 103\. An R-R interval represents what on the EKG? a\) Two complete cardiac cycles b\) Rest and Relaxation c\) One complete cardiac cycle d\) Inferior MI **104.The image formed by retina of human eye is:** **a) Virtual and erect** **b) Real and inverted** **c) Virtual and inverted** **d) Real and erect** **105. The change in focal length of human eye is caused due to -- ** **a)** Ciliary muscles b\) Pupil **c)** Cornea d\) Iris 106\. **The least distance of distinct vision for a young adult with normal vision is:**\ **a) 25m** **b) 20m** **c) 25cm** **d) 20cm** **107. The persistence of vision for human eye is-** **a)** 1/10th of a sec b\) 1/16th a sec c\) 1/6th a sec d\) 1/18th of a sec **108. The light sensitive cell present on retina and is sensitive to the intensity of light is:** **a)** Cones b\) Rod cell c\) Both cone and rod cells d\) None **109.** **The phenomenon of light responsible for the working of human eye is:** a\) Reflection\ b) Refraction\ c) Power of accommodation\ d) Persistence of vision **110.Which of the following colors is least scattered by fog, dust or smoke:**\ a) Violet\ b) Blue\ c) Red\ d) Yellow **111.The colored light that reflects most while passing through a prism is:**\ a) Yellow\ b) Violet c\) Blue\ d) Red **112. The amount of light entering the eye is controlled by:          **\ a) Ciliary muscles\ b) Pupil\ c) Cornea\ d) Iris **113. The part of the eye which refracts light entering the eye from external objects:**\ a) Lens\ b) Cornea\ c) Iris\ d) Pupil **114. The variation of focal length to form a sharp image on the retina is called \-\-\--.**\ a) Accommodation\ b) Aperture\ c) Retina control\ d) Sutter **115. In human eye image is formed:**\ a) Behind retina\ b) In front of retina\ c) On retina\ d) In between lens and retina **116. Light enters eye through a transparent membrane called:**\ a) Cornea\ b) Pupile\ c) Iris\ d) Retina **117. Colored portion of eye that controls amount of light reaching retina is called:**\ a) Cornea\ b) Pupil\ c) Retina control\ d) Iris **118. Human eye acts like a \-\-\-\-\-\--.**\ a) Endoscope\ b) Camera\ c) Telescope\ d) Microscope 119. **The passage through which tears pass is:**\ a) Cornea\ b) Tear gland\ c) Tear duct\ d) Eyeball **120. The part of eye that is a messenger of electrochemical signals from eye to brain is called:**\ a) Blood vessel\ b) Optic nerve\ c) Iris\ d) Cornea **121. Thing that shuts automatically to protect eyes is known as:         **\ a) Eyelash\ b) Eyelid\ c) Iris\ d) Cornea **122. Ability of combination of dual vision of eyes is called:       **\ a) Dim vision\ b) Concave vision\ c) Binocular vision\ d) Bright vision **123. For a young adult with normal vision the far point is:         **\ a) 20cm\ b) 20m\ c) 20Km\ d) Infinity **124. Sunlight is a mixture of \_\_ visible colors**\ a) 5\ b) 6\ c) 7\ d) none **125. The effect of glass prism is only to separate the seven colors of**\ a)White light b\) light from bulb\ c) Sunlight\ d) All **126.The \_\_ color is at the top and   \_\_\_\_ color is at the bottom of spectrum.** a\) Red, Violet\ b) Red, Blue\ c) Violet, red\ d) None **127. Who discovered the experiments with glass prism that white light consists of seven colors**\ a) Newton\ b) Faraday\ c) Maxwell\ d) Young **128. The light that refracts most while passing through a prism**\ a) Red\ b) Violet\ c) Indigo\ D. Yellow **129.The rod cells responds to**\ a) Color of light\ b) Low light levels\ c) Intensity of light\ d) None **130. Which of the following colors is the least deviated on passing through a prism:**\ a) Red\ b) Yellow\ c) Violet\ d) Indigo **131. Cornea is a transparent spherical structure which \_\_\_\_      **\ a) Reflects light\ b) Refracts light\ c) Scatters light\ d) None **132. The image on the retina remains for 1/16th of sec. This is called as:**\ a) Accomodation\ b) Persistence of vision\ c) Both a and b\ d) None **133. The middle vascular layer that darkens the eye from inside and prevents internal reflection is:**\ a) Choroid\ b) Sclera\ c) Retina\ d) Cornea 134. **The eye lens is a**\ a) Transparent double convex lens\ b) Transparent double concave lens\ c) Transparent concave convex lens\ d) None **135. The eye lens contains a liquid called:**\ a) Aqueous humour\ b) Peroxide\ c) Vitreous humour\ d) None **136. Long sightedness is caused by eyeball being too short. It can be corrected by:**\ a) Using convergent lens\ b) Plane mirror\ c) Divergent lens\ d) None **137. Astigmatism occurs when the cornea does not have a truly spherical shape. The defect can be cured by:**\ a) Concave lens\ b) Cylindrical shape\ c) Convex lens\ d) Plane convex lens **138. The power of lens being +4 D, suggests that it is:**\ a) Convex lens\ b) Plane convex lens\ c) Concave lens\ d) none **139.  When an object moves towards a convex lens the size of image \_\_\_\_\_.**\ a) Decreases\ b) Increases\ c) First decreases then increases\ d) Remains the same 140\. What does PET in PET scan stand for? a\) Positron Emission Test b\) Photon Emission Technology c\) Positron Emission Tomography d\) Proton Emission Tomography 141\. PET is primarily used for which of the following purposes? a\) Imaging bones b\) Functional imaging of tissues c\) Diagnosing fractures d\) Structural imaging 142\. Which type of radiation is detected in PET scans? a\) Alpha radiation b\) Beta radiation c\) Gamma radiation d\) X-rays 143.The tracer used in PET scans typically emits: a\) Electrons b\) Positrons c\) Neutrons d\) Photons 144\. The most commonly used tracer in PET scans is: a\) Carbon-14 b\) Fluorodeoxyglucose (FDG) c\) Iodine-131 d\) Technetium-99m 145\. PET scans are widely used in the diagnosis of: a\) Bone fractures b\) Neurodegenerative diseases c\) Skin conditions d\) Muscle injuries 146\. FDG, the commonly used tracer, is an analog of: a\) Protein b\) Glucose c\) Lipids 147\. PET scans can detect cancer by visualizing: a\) Increased blood flow b\) Increased metabolic activity c\) Decreased oxygen levels d\) Cell membrane thickness 148\. The positron emitted in a PET scan interacts with an electron to produce: a\) Beta particles b\) Two gamma photons c\) Alpha particles d\) X-rays 149\. The gamma photons in PET scans are emitted at an angle of: a\) 90° b\) 120° c\) 180° d\) 360° 150\. PET scans are commonly combined with which imaging technique for better accuracy? a\) Ultrasound b\) X-ray c\) MRI d\) CT 151\. The half-life of FDG is approximately: a\) 110 seconds b\) 110 minutes c\) 24 hours d\) 7 days 152\. PET is most commonly used to assess: a\) Blood pressure b\) Oxygen levels c\) Organ function d\) Bone density 153\. Which field is NOT a common application of PET scans? a\) Oncology b\) Cardiology c\) Neurology d\) Dermatology 154\. PET scans are beneficial in diagnosing Alzheimer's disease because they detect: a\) Tumors b\) Glucose uptake abnormalities c\) Fractures in the brain d\) Blood clots 155\. The source of positrons in PET is: a\) Stable isotopes b\) Radionuclides c\) Heavy metals d\) Non-radioactive substances 156\. A PET scan is particularly sensitive for imaging: a\) Soft tissues b\) Bones c\) Metabolic processes d\) Hair follicles a\) Outside the body b\) At the scanner detector c\) In the tissue being imaged d\) In the tracer source 158\. Which of these isotopes is commonly used in PET tracers? a\) Iodine-131 b\) Carbon-11 c\) Technetium-99m d\) Thorium-234 159\. PET scans are helpful in assessing heart conditions because they: a\) Visualize blood flow b\) Measure heart rate c\) Assess muscle thickness 160.Which imaging modality uses a cyclotron to produce tracers? a\) X-ray b\) MRI c\) PET d\) CT 161\. PET scans are useful in identifying active cancer because cancer cells: a\) Consume more oxygen b\) Divide rapidly c\) Absorb more glucose d\) Emit radiation 162\. The spatial resolution of PET is typically: a\) Better than MRI b\) Similar to X-ray c\) Coarser than CT 163\. Which of the following is NOT a limitation of PET scans? a\) High cost b\) Low spatial resolution c\) Radiation exposure d\) Limited availability of CT integration 164\. PET scans can detect early changes in: a\) Structure b\) Function c\) Mass d\) Density 165\. PET scanners require: a\) Low-power electricity b\) A stable external magnetic field c\) Shielding from gamma rays d\) A radioactive tracer 166\. PET scans are contraindicated for: a\) Pregnant women b\) Diabetic patients c\) Young adults d\) Athletes 167\. Dual-modality PET-CT scans provide information about: a\) Function and structure b\) Blood flow and temperature c\) Density and elasticity d\) Surface and depth 168\. Which organ is naturally more active and can appear brighter on PET scans? a\) Heart b\) Kidneys c\) Liver d\) Brain 169\. PET tracers are injected into the body: a\) Intramuscularly b\) Intravenously c\) Subcutaneously d\) Orally 170\. What does the acronym LASER stand for? a\) Light Amplification by Stimulated Emission of Radiation b\) Light Amplification by Spontaneous Emission of Radiation c\) Light Amplification by Stimulated Emission of Rays d\) Light Application by Stimulated Emission of Radiation 171\. Which of the following is NOT a property of laser light? a\) Coherence b\) Monochromaticity c\) Divergence d\) Directionality 172\. What is coherence in laser light? a\) Light of different wavelengths b\) Light waves that are in phase c\) Light that spreads out in all directions d\) Light of high intensity 173\. Which component in a laser generates the initial light? a\) Gain medium b\) Optical cavity c\) Pumping mechanism d\) Reflector 174\. What is the role of the optical cavity in a laser? a\) Absorb light b\) Amplify light by reflection c\) Change wavelength of light d\) Split light into components 175\. Which of the following is a common type of laser used in medicine? a\) Semiconductor Laser b\) Nd:YAG Laser c\) Ruby Laser d\) All of the above 176\. What is the main advantage of a CO₂ laser in surgery? a\) Ability to cut soft tissues with precision b\) Ability to penetrate deep tissues c\) Reduced risk of thermal damage d\) Low cost 177\. Which laser is most commonly used for eye surgeries like LASIK? a\) Excimer Laser b\) Nd:YAG Laser c\) Argon Laser d\) CO₂ Laser 178\. What is the typical wavelength of an Nd:YAG laser? a\) 355 nm b\) 532 nm c\) 1064 nm d\) 1550 nm 179\. Which of the following lasers is used for photodynamic therapy in cancer treatment? a\) Dye Lasers b\) CO₂ Laser c\) Excimer Laser d\) Ruby Laser 180\. In laser surgery, why is laser light preferred over traditional scalpel methods? a\) Reduced bleeding b\) Enhanced precision c\) Sterilization of the surgical site d\) All of the above 181\. What is the principle of photocoagulation in laser therapy? a\) Vaporizing tissue with intense heat b\) Coagulating blood vessels to stop bleeding c\) Breaking tissue bonds without heat d\) Generating light to sterilize tissue 182\. Which of the following medical fields commonly uses lasers? a\) Dermatology b\) Ophthalmology c\) Oncology d\) All of the above 183\. How does a laser work in dermatology for skin rejuvenation? a\) Removing the top layer of the skin b\) Stimulating collagen production c\) Reducing melanin deposits d\) All of the above 184\. Which laser treatment is used for breaking kidney stones? a\) Excimer Laser b\) Holmium Laser c\) CO₂ Laser d\) Argon Laser 185\. What is photodynamic therapy (PDT)? a\) A treatment combining light and a photosensitizing agent b\) Direct tissue cutting using laser c\) Generating X-rays using lasers d\) None of the above 186\. How are lasers used in cancer treatment? a\) Destroying tumor cells b\) Activating photosensitizing agents c\) Precisely targeting tissues d\) All of the above 187\. Which laser is preferred for treating retinal detachment? a\) Argon Laser b\) Excimer Laser c\) Ruby Laser d\) Nd:YAG Laser 188\. In laser hair removal, what property of laser light is used? a\) Melanin absorption b\) Coherence of light c\) Low energy emission d\) High divergence 189\. Which medical condition is treated using low-level laser therapy (LLLT)? a\) Chronic pain b\) Wound healing c\) Inflammation d\) All of the above 190\. What biophysical process occurs during laser ablation? a\) Vaporization of tissue b\) Coagulation of blood vessels c\) Breaking DNA bonds d\) Stimulating cellular repair 191\. Which property of tissue primarily determines laser absorption? a\) Tissue color b\) Water content c\) Density of tissue d\) Presence of fat 192\. What is the primary chromophore for CO₂ laser absorption? a\) Hemoglobin b\) Water c\) Melanin d\) Collagen 193\. How does laser wavelength affect tissue penetration? a\) Longer wavelengths penetrate deeper b\) Shorter wavelengths penetrate deeper c\) All wavelengths penetrate equally d\) Wavelength does not affect penetration 194\. Why is laser light highly focused? a\) Coherence and directionality b\) Divergence of beam c\) Monochromaticity and coherence d\) Monochromaticity and divergence 195\. What happens to tissue when exposed to high-energy laser pulses? a\) Vaporization b\) Coagulation c\) Carbonization d\) All of the above 196\. Which interaction of lasers with tissues is used in cutting and vaporization? a\) Thermal interaction b\) Photochemical interaction c\) Photomechanical interaction d\) None of the above 197\. What is the photothermal effect in laser-tissue interaction? a\) Tissue is heated by laser light b\) Tissue is cooled by laser light c\) Tissue absorbs light without heating d\) None of the above 198\. What is the function of cooling systems during laser surgery? a\) Enhance tissue absorption b\) Prevent overheating and thermal damage c\) Increase light coherence d\) Amplify laser energy 199\. Which safety measure is essential during laser procedures? a\) Protective eyewear b\) Ventilation to remove smoke c\) Proper wavelength calibration d\) All of the above 200\. What is the primary imaging technique used in angiography? a\) MRI b\) X-ray c\) Ultrasound d\) CT scan 201\. Which physical principle is most important for visualizing blood vessels in X-ray angiography? a\) Reflection b\) Absorption c\) Refraction d\) Diffusion 202\. In X-ray angiography, contrast agents are used because they: a\) Reduce radiation dose b\) Improve image contrast c\) Increase image resolution d\) Protect tissues 203\. What type of radiation is utilized in angiography? a\) Gamma rays b\) X-rays c\) Infrared radiation d\) Microwaves 204\. The attenuation of X-rays in tissues is primarily dependent on: a\) Tissue density b\) Tissue temperature c\) Magnetic properties d\) Conductivity 205\. Contrast agents used in angiography are typically based on which element? a\) Iodine b\) Calcium c\) Iron d\) Sulfur 206\. Why is iodine commonly used in contrast agents for angiography? a\) High atomic number b\) Low cost c\) Strong magnetic properties d\) Low toxicity 207\. The main risk associated with contrast agents in angiography is: a\) Radiation exposure b\) Nephrotoxicity c\) Cardiac arrhythmias d\) Hyperthermia 208\. In angiography, contrast agents enhance image clarity by: a\) Increasing X-ray absorption in blood vessels b\) Decreasing tissue scattering c\) Reducing X-ray attenuation in tissues d\) Reflecting X-rays 209\. Gadolinium-based contrast agents are used in which type of angiography? a\) CT angiography b\) Digital subtraction angiography c\) MRI angiography d\) Fluoroscopy 210\. Digital subtraction angiography (DSA) is primarily used to: a\) Reduce motion artifacts b\) Remove background tissues c\) Increase spatial resolution d\) Enhance temporal resolution 211\. In DSA, the "subtraction" process involves: a\) Adding images taken before and after contrast injection b\) Removing the pre-contrast image from the post-contrast image c\) Enhancing the brightness of blood vessels d\) Using polarized light 212\. CT angiography differs from traditional X-ray angiography because it: a\) Does not use ionizing radiation b\) Provides 3D imaging c\) Does not require a contrast agent d\) Is less sensitive to motion artifacts 213\. Fluoroscopy is used in angiography to: a\) Create static images of blood vessels b\) Monitor blood flow in real-time c\) Reduce radiation exposure d\) Enhance contrast resolution 214\. MRI angiography avoids radiation exposure by using: a\) Ultrasound waves b\) Magnetic fields and radio waves c\) Infrared imaging d\) Gamma rays 215\. What is the unit of radiation dose commonly used in angiography? a\) Sievert b\) Gray c\) Becquerel d\) Coulomb/kg 216\. The primary factor affecting X-ray penetration through tissues is: a\) Wavelength b\) Frequency c\) Photon energy d\) Amplitude 217\. Scatter radiation in angiography can be reduced by: a\) Using a higher X-ray tube current b\) Collimating the X-ray beam c\) Increasing the exposure time d\) Removing the contrast agent 218\. What is the main source of patient radiation exposure in angiography? a\) Scatter radiation b\) Direct beam exposure c\) Secondary radiation d\) Background radiation 219\. To minimize radiation exposure, angiography procedures use: a\) High-energy X-rays b\) Shorter exposure times c\) Lower contrast agent volumes d\) Higher frame rates 220\. Angiography is commonly used to diagnose: a\) Tumors b\) Bone fractures c\) Vascular diseases d\) Neurological disorders 221\. Which blood vessels are typically visualized in coronary angiography? a\) Arteries of the legs b\) Coronary arteries c\) Pulmonary veins d\) Jugular veins 222\. What is a primary advantage of 3D rotational angiography? a\) Lower radiation dose b\) Improved visualization of vessel structure c\) Faster procedure time d\) Reduced need for contrast agents 223\. Endovascular procedures like stent placement are often guided by: a\) DSA b\) Fluoroscopy c\) Ultrasound d\) MRI 224\. In interventional angiography, which technology allows precise catheter placement? a\) Fluoroscopy b\) CT imaging c\) MRI d\) Doppler ultrasound 225\. Poiseuille's law is relevant in angiography because it describes: a\) Blood vessel elasticity b\) Blood flow resistance c\) Contrast agent diffusion d\) X-ray attenuation 226\. Turbulent blood flow is characterized by: a\) High Reynolds number b\) Laminar motion c\) Uniform velocity d\) Low viscosity 227\. The contrast agent dispersion in blood is influenced by: a\) Blood viscosity and velocity b\) Blood pressure alone c\) X-ray intensity d\) Tissue temperature 228\. Which property of blood affects X-ray attenuation during angiography? a\) Density b\) Magnetic susceptibility c\) Conductivity d\) Optical absorption 229\. The wall shear stress in blood vessels can be evaluated to: a\) Detect vessel stenosis b\) Assess contrast agent toxicity c\) Minimize radiation exposure d\) Optimize imaging protocols 230\. What is the Gamma Knife primarily used for? A\) Open surgeries B\) Non-invasive brain surgeries C\) Dental procedures D\) Cardiac surgeries 231\. What type of radiation does the Gamma Knife use? A\) Alpha particles B\) Beta particles C\) Gamma rays D\) X-rays 232\. What is the source of gamma rays in the Gamma Knife? A\) Uranium-235 B\) Cobalt-60 C\) Radium-226 D\) Cesium-137 233\. How many gamma ray beams are typically focused on the target in a Gamma Knife system? A\) 50 B\) 192 C\) 360 D\) 1000 234\. What is the principle behind the Gamma Knife? A\) High-intensity laser ablation B\) Converging multiple low-dose gamma rays to deliver a high dose at a focal point C\) Thermal coagulation of tissues D\) Fragmentation of DNA by alpha particles 235\. Why is the Gamma Knife considered non-invasive? A\) It uses external beams focused on the target B\) It involves a small incision C\) It uses heat to treat the tissue D\) It requires no anesthetic 236\. Which imaging modality is commonly used for targeting in Gamma Knife procedures? A\) X-ray B\) MRI C\) CT D\) Ultrasound 237\. What is the main advantage of using Cobalt-60 in the Gamma Knife? A\) Long half-life B\) High-energy gamma emission C\) Stability during use D\) All of the above 238\. How is the patient\'s head immobilized during Gamma Knife treatment? A\) Using a flexible mask B\) Using a stereotactic frame C\) By manual holding D\) Through sedation 229\. What is the half-life of Cobalt-60 used in the Gamma Knife? A\) 2 years B\) 5.27 years C\) 10 years D\) 20 years 240\. What is the primary biological effect of gamma rays on tissue? A\) Thermal damage B\) DNA strand breaks C\) Inducing chemical bonds D\) Mechanical disruption 241\. What is the therapeutic mechanism of the Gamma Knife? A\) Ionizing radiation damages the DNA of tumor cells, leading to apoptosis B\) Stimulating cell growth in damaged areas C\) Generating heat to destroy tissues D\) Mechanical cutting of tissues 242\. Which tissue characteristic affects the absorption of gamma rays? A\) Tissue density B\) Tissue water content C\) Atomic number of tissue elements D\) All of the above 243\. What is the range of penetration of gamma rays in human tissues? A\) Very shallow (\< 1 mm) B\) Intermediate (1--10 cm) C\) Deep (up to several meters) D\) Infinite 244\. What is the role of oxygen in enhancing the effectiveness of gamma rays? A\) Inhibits DNA repair mechanisms B\) Produces free radicals to increase DNA damage C\) Absorbs gamma rays to increase dose D\) None of the above 245\. Which of the following conditions is commonly treated using the Gamma Knife? A\) Brain tumors B\) Arteriovenous malformations (AVMs) C\) Trigeminal neuralgia D\) All of the above 246\. Which type of brain tumor is most commonly treated with the Gamma Knife? A\) Glioblastoma B\) Meningioma C\) Pituitary adenoma D\) All of the above 247\. What is the advantage of Gamma Knife radiosurgery over traditional surgery? A\) No risk of infection B\) No need for anesthesia C\) Minimal recovery time D\) All of the above 248\. How does the Gamma Knife treat arteriovenous malformations (AVMs)? A\) Coagulates blood vessels using heat B\) Induces fibrosis and closure of abnormal vessels using radiation C\) Removes vessels surgically D\) Blocks blood flow chemically 249\. Which condition is treated using Gamma Knife to reduce facial pain? A\) Trigeminal neuralgia B\) Migraine C\) Epilepsy D\) Stroke 250\. Gamma Knife is NOT typically used for which of the following conditions? A\) Lung cancer B\) Brain metastases C\) Acoustic neuroma D\) Epilepsy 251\. How does the Gamma Knife treat epilepsy? A\) Stimulates neurons electrically B\) Targets and destroys the epileptic focus C\) Coagulates blood vessels near the focus D\) Reorganizes neuronal circuits 252\. Which non-cancerous condition can also be treated with the Gamma Knife? A\) Parkinson's tremors B\) Hydrocephalus C\) Cerebral palsy D\) Seizure disorders 253\. How is dose distribution controlled in Gamma Knife radiosurgery? A\) By adjusting the number of beams focused on the target B\) By changing the energy of gamma rays C\) By varying beam diameters D\) Both A and C 254\. What is the effect of gamma radiation on normal tissue surrounding the target? A\) Minimal due to precise beam focusing B\) Significant due to high radiation intensity C\) Uniform damage across all tissues D\) None of the above 255\. What is the most common side effect of Gamma Knife treatment? A\) Headache B\) Hair loss C\) Skin burns D\) Nausea 256\. What is a major limitation of Gamma Knife radiosurgery? A\) Limited to treating conditions within the skull B\) High risk of infection C\) Ineffectiveness for tumors \> 5 cm D\) Both A and C 257\. What is the typical recovery time after Gamma Knife radiosurgery? A\) 1--2 days B\) 1 week C\) 1 month D\) 6 months 258\. How often is re-treatment with the Gamma Knife required? A\) Never B\) Rarely, depending on the condition C\) Every 6 months D\) Annually 259\. Which of the following is essential during Gamma Knife treatment for safety? A\) Patient immobilization B\) Radiation shielding C\) Real-time imaging D\) All of the above **260. A semiconductor is formed by......... bonds.** a\) Covalent b\) Electrovalent c\) Coordinate d\) None of the above **261. A semiconductor has............ temperature coefficient of resistance.** a\) Positive b\) Zero c\) Negative d\) None of the above **262. The most commonly used semiconductor is...........** a\) Germanium b\) Silicon c\) Carbon d\) Sulphur **263. A semiconductor has generally.................. valence electrons.** a\) 2 b\) 3 c\) 6 d\) 4 **264. The resistivity of pure germanium under standard conditions is about..........** a\) 6 x 104Ω cm b\) 60Ω cm c\) 3 x 106Ω cm d\) 6 x 10--⁴Ω cm **265. The resistivity of a pure silicon is about...............** a\) 100 Ω cm b\) 6000 Ω cm c\) 3 x 105 Ω m d\) 6 x 10-8 Ω cm **266. When a pure semiconductor is heated, its resistance..............** a\) Goes up b\) Goes down c\) Remains the same d\) Can't say **267. The strength of a semiconductor crystal comes from........** a\) Forces between nuclei b\) Forces between protons c\) Electron-pair bonds d\) None of the above **268. When a pentavalent impurity is added to a pure semiconductor, it becomes.........** a\) An insulator b\) An intrinsic semiconductor c\) p-type semiconductor d\) n-type semiconductor **269. Addition of pentavalent impurity to a semiconductor creates many........** a\) Free electrons b\) Holes c\) Valence electrons d\) Bound electrons **270. A pentavalent impurity has.......... Valence electrons** a\) 3 b\) 5 c\) 4 d\) 6 **271. An n-type semiconductor is.........** a\) Positively charged b\) Negatively charged c\) Electrically neutral d\) None of the above **272. A trivalent impurity has..... valence electrons** a\) 4 b\) 5 c\) 6 d\) 3 **273. Addition of trivalent impurity to a semiconductor creates many........** a\) Holes b\) Free electrons c\) Valence electrons d\) Bound electrons **274. A hole in a semiconductor is defined as................** a\) A free electron b\) The incomplete part of an electron pair bond c\) A free proton d\) A free neutron **275. The impurity level in an extrinsic semiconductor is about..... of pure semiconductor.** a\) 10 atoms for 108 atoms b\) 1 atom for 108 atoms c\) 1 atom for 104 atoms d\) 1 atom for 100 atoms **276. As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor**........... a\) Remains the same b\) Increases c\) Decreases d\) None of the above **277. A hole and electron in close proximity would tend to..........** a\) Repel each other b\) Attract each other c\) Have no effect on each other d\) None of the above **278. In a semiconductor, current conduction is due to........** a\) Only holes b\) Only free electrons c\) Holes and free electrons d\) None of the above **279. The random motion of holes and free electrons due to thermal agitation is called..........** a\) Diffusion b\) Pressure c\) Ionisation d\) None of the above 280\. Most of space in an atom is a\) filled with positive charge b\) empty c\) filled with negative charge d\) filled with neutrons