Physics

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1. Which mode(s) of ultrasonography provides a direct information about the amplitude of echoes:

  • B – mode only
  • A-mode only
  • A and B modes
  • A and M modes
  • M – mode only

2. After the light absorption by a photoreceptor the membrane potential is:

  • A) Hyperpolarized due to closure of cation selective channels activated by cyclic GMP
  • A) Depolarized due to opening of voltage-gated sodium channels
  • A) Hyperpolarized due to opening of voltage-gated calcium channels
  • A) Depolarized due to opening of cation selective channels activated by cyclic AMP
  • Hyperpolarized due to closure of cation selective channels activated by cyclic AMP

The force of electrostatic interaction between two electric charges is:

  • proportional to the product of the two electrical charges
  • Proportional to the distance between electrical charges
  • inversely proportional to the distance between electrical charges
  • Proportional to the square of the distance between electrical charges
  • Inversely proportional to the sixth power of the distance

4) The energy ofd is:

  • Inversely proportional to the sixth power of the distance
  • Proportional to the square of the distance between electrical charges
  • Proportional to the distance between electrical charges
  • Inversely proportional to the distance between electrical charges
  • Inversely proportional to the square of the distance between electrical charges

5. Van der Waals attractive interactions are due to

  • dipole interactions
  • hydrogen bonds
  • short distance strong (rigid) repulsion
  • covalent reactions
  • energy supplied by external force when decreasing the system entropy

6) Radiation-induced ionization of gas occurs in:

  • Geiger counter
  • scintillation counter
  • photographic film
  • galvanometer
  • semiconductor counter

7) The sample contains 2000 atoms of radioactive isotope whose half-life is 50 years. Radioactive decays will reduce the initial number of radioactive atoms to 125 after:

  • A. 200 years
  • A. 100 years
  • A. 187,5 years
  • A. 250 years
  • A. 375 years

8) During MRI scan a patient is placed in the constant magnetic field of a scanner and the protons in patient’s body absorb pulses of electromagnetic radiation whose frequency is typical for:

  • A. radio waves
  • A. X-ray
  • A. infrared
  • A. ultraviolet
  • A. microwaves

9) In ultrasonography reflections of ultrasound waves (echos) may occur at the boundary between two tissues:

  • A. if both tissues have dissimilar acoustic resistances
  • A. if both tissues have the same acoustic resistances
  • A. if both tissues have the same densities
  • A. if the boundary is very close to a transducer
  • A. if the boundary lays inside near field of a transducer

10) The underwater rock is 6 km from a submarine. What is the time (starting from sound emission) of echo return to the sonar if the speed of sound in water is 1500 m/s?

  • A. 8 s
  • A. 2 s
  • A. 4 s
  • A. 1.5 s
  • A. 3 s

11) The NMR phenomenon is related to:

  • absorption of quanta of electromagnetic radiation correlated with change in the spin moment orientation
  • emission of ultrafiolet radiation
  • emission of gamma rays from atomic nuclei
  • absorption of infrared radiation
  • absorption of energy carried by ultrasounds

12) The mean kinetic energy of particles in an ideal gas is:

  • proportional to the temperature
  • inversely proportional to the temperature
  • inversely proportional to the pressure
  • proportional to the pressure
  • proportional to the volume

13) The intensity of the electric al field (E = U/d, U – voltage, d – distance) within the biological membrane is close to:

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14. The phenomenon of viscosity is related to:

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15. Viscous resistance (haemodynamic resistance) is defined as:

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16) After action potential generation in the axon:

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17) Which element of the eye’s optic system shows the highest optic power (measured in Dioptres):

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18) If the curvature radii of the lens increases 2 fold, then the optic power (measured in dioptres) of the lens:

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19) Accommodation of the eye is related to:

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20) mechanism of accommodation is related to the properties of

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21) When the action potential reaches its maximal (peak) value, the membrane potential reaches approximately:

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22) When the action potential reaches its minimal value (hyperpolarization), the neuronal membrane is

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23) Electrical capacitance of a membrane:

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24) The acetylcholine receptors at the end plate in the muscle fiber are:

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24) Decrease in potassium ion concentration in the extracellular fluids would cause:

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26) Entropy is a measure of :

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27) If the radius of a cylindrical vessel decreases 2 fold then the haemodynamic resistance:

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28) Fick’s law states that

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29) Detection of signals characterized by a low frequency (tens of Hz) occurs at the basilar membrane:

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30) Switching off the dark current in the rod takes place due to:

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31) Ganglion cells innervating the retina beyond the fovea:

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32 The Weber-Fechner law states that

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33) In the case of the Nernst equilibrium

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34) Opening of potassium channel would result in :

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35) Indicate the appropriate association:

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36) The lens has optic power of -5 dioptres

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37) Total optic power of the human eye is approximately:

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38) The distance of the object from a thick lens is calculated as:

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39) Which of the statements below is correct

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40) When the membrane potential is at its resting level

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41) Inactivation of sodium channels

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42) Which neurotransmitter is released during the neuromuscular transmission

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43) Neuromuscular transmission results in:

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44) Indicate where are localized the hierarchical pacemakers in the heart (starting from that working with highest frequency):

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45) The plateau phase of the action potential generated by a Purkynje cells lasts approximately

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46) Choose the proper association:

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47) For the ideal fluid, when the pressure is constant and the diameter of tube is increased 2-fold, the velocity of flow will:

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48) In the closed system, when the volume of the system is compressed (a small volume change V), the internal energy will change by (p – pressure, T-temperature, k – Bolzmann constant)

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49) The first principle of thermodynamics for ideal gas states that the change of internal energy of a closed system is equal to:

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50) When the function of the f channels in the sinoatrial node is increased :

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