Biophysics

313)  The sound wave travels within the medium M1 and enters the medium M2 crossing the interface between these two media. The acoustic impedance for M1 and M2 are 3 kg.m-²s and 1 kg.m-2s, respectively. Indicate the value of the reflection coefficient.

314)  The ultrasonograph emits a pulse of ultrasound wave into the examined material at time t=0. The echo is detected after 0.2 ms (millisecond). Assuming the sound velocity in the material 500m/s, indicate the distance between the ultrasonography’s head and the object from which the sound was reflected:

315)  The Fourier theorem concerns

316)  At a defined frequency (1000 Hz) how much the sound intensity needs to be increased to increase the sensation of sound loudness by 200%.

317)  Two sounds were found to be characterized by the same basal frequency but different weights of higher harmonics. When listening these sounds we will report that

318)  When channels open in the cilia of hair cells in the organ of Corti the flux of ions can be characterized as:

319)  Which types of cells form the most numerous input into the spiral ganglion cells

320)  The major role of the outer hair cells in the Corti apparatus is

321)    The effect used in Geiger-Mueller counter function is

322)     If Ec is the energy of characteristic radiation, Eh – energy of breaking radiation and Et the heat produced in X-Ray tube, then

323)    The main dangerous products of water radiolysis are

324)    In photodynamic therapy the energy of light is absorbed by

325)     Amorphus silicon is used in active matrix panels in the following purpose

326)     Comparing the energies carried by different ionization radiations (α,β, γ, X) we obtain

328)     Hounsfield units are used

329)     In confocal microscopy an image of a certain…

330)  The molecular mechanism of diffusion is based on

331)  The osmotic pressure can be described as

332)  At Nernst equilibrium the electric field causes the migration flow

333)  when comparing simple diffusion and facilitated diffusion the right conclusion is

334)  Sodium Potassium pump is an active transport mechanism because

335)  Comparing the membrane permeability for different ions in the.. one can write

336)  Increase of the extracellular concentration of potassium ions will cause following change of the neurons membrane resting potential

337)  Voltage-sensitive channel is a

338)  Functional components of ligand-gated channels are

339)  Threshold depolarization of a cell is

340)  Depolarization phase of action potentials of different cells may be caused by

25) Electron and proton are exposed to the same homogenous electric field.

37)    Electric charge q is moving with velocity v in the magnetic field characterized by induction B. Assuming that velocity vector is perpendicular to the induction vector B, the force acting on the charge will have the orientation:

43)    The relaxation time T1 is determined in the experimental protocol in which (syn… MZ  is the component of magnetization M parallel to external magnetic field BO pulse  - radio frequency electromagnetic wave with magnetic component perpendicular to BO)

48)  Sound velocity:

50)  Which phenomenon requires the highest energy of photon:

81)                The mechanical vibration damped

82)                According to the theory of Mitchell:

83)               The sequence of events leading to muscle contraction occurs:

119)  the  sequence of events happening in rod cells after illumination is properly described

124)  blood flow in aorta is

125)  Photon scattered in Compton effect

128)  Denoting by v-velocity of action potential propagation, C-membrane capacitance, R-membrane resistance for myelin sheath we may write

132)  the following sentence about motor unit is NOT TRUE