Fysik Part 2

Front 1

When a man moes his sight from a book at 25cm to a start (infinity) the power of his eye optical system changes by:

Back 1

4 Dioptries

Front 2

The wavelength of a sound wave in air of the highest pitch audible by humans is about:

Back 2

17mm

Front 3

A person has a far point at 4.0m. The lens that will correct this defect have a power of:

Back 3

-0.25D

Front 4

The spreading out of molecules from a region of the higher concretion is caused by:

Back 4

the random movement of molecules

Front 5

In processes of a)hemodialysis and b)hemofiltration: the driving force are:

Back 5

a=concetrion difference b=pressure difference

Front 6

A neuron with refractory period 1 ms can transmit signals with maximal frequency of:

Back 6

1 kHz

Front 7

The information about stimulus intensity is coded in neurons by:

Back 7

the frequency of the action potential impulses

Front 8

Two statements that refer to the state of thermodunamic equilibrium:

Back 8

It is a macroscopic representation of the highest number of microstates + in this state are no systematic unbalanced flow of energy and/or matter

Front 9

“Wind chill factor” relates the air temperature with actual apparent temperature felt on exposed skin. The diffrencene between the two temperatures is mainly related the processes of:

Back 9

convection

Front 10

At the depth of 10 m in water pressure exerted on a divers eardrum is higher them that at the surface by:

Back 10

10^5

Front 11

The contrast between different tissues od radiographs is due to therie difference in:

Back 11

mass density and elemental composition

Front 12

The best contrast on medical images between different SOFT TISSUES is provided by:

Back 12

MRI

Front 13

What is electromagnetic radiation:

Back 13

A wave which consist of oscillating electrical and magnetic fields

Front 14

Consider two equal compartments of water solutions separated with a membrane. The compartments contain: I – 103 molecules of glucose (the mole weight of glucose 180)

II – 103 molecules of sucrose (the mole weight of sucrose is 342).

The osmotic water flow will go a) from I to II b) from II to I c) there is no water movement d) the answer depends on temperature and pressure:

Back 14

there is no water movement

Front 15

The diffusion potential across the membrane is created only when
a) the membrane is not permeable for one kind of ions
b) the ions has different mobility in the membrane
c) the ions have different mobility and there is a difference in ions concentration between two solutions separated by the membrane
d) there is difference in ion concentration between two membrane sides:

Back 15

the ions have different mobility and there is a difference in ions concentration between two solutions separated by the membrane

Front 16

Knowing the value of the respiratory quotient (RQ) one can:
a) estimate the total energy consumption of a body b) calculate the amount of heat released in metabolic processes
c) get information on type of food components used as substrates in cellular respiration
d) estimate the total of work and heat given away by an organism:

Back 16

get information on type of food components used as substrates in cellular respiration

Front 17

The annual dose from natural background of ionizing radiation in Poland is 3.6 mGy. It means that average man will absorb in one year total energy of the radiation about

Back 17

270 mJ

Front 18

A characteristic of ionizing radiation most closely related to its radiobiological effectiveness is: a. Dose b. Exposure c. Linear energy transfer (LET) d. Photon or particle energy:

Back 18

c. Linear energy transfer (LET)

Front 19

The average dose of X-rays delivered to a 70 kg patient undergoing total body irradiation was 60 Gy. The total energy of X-rays absorbed by the patient’s body was:

Back 19

a. 4200 J

Front 20

Transmural pressure inside a vessel with stenosis in comparison to normal vessel conditions is: a) the same b) higher c) lower d) higher in veins and lower in arteries:

Back 20

c) lower

Front 21

Contrast between different tissues on MRI images is due to their difference in:
a) hydrogen concentration
b) density,
c) proton density and effectiveness of energy exchange between protons and between protons and surrounding molecules
d) elemental composition and microscopic mobility of molecules and atoms:,

Back 21

proton density and effectiveness of energy exchange between protons and between protons and surrounding molecules

Front 22

Some processes responsible for interaction of high energy X-rays with patient’s body lead to generation of secondary high energy photons coming out of the body. This happens:
a. Only in Compton effect
b. Mainly in photoelectric effect
c. Mainly in Compton effect and pair-creation effect d. Only in pair-creation effect

Back 22

B Mainly in photoelectric effect

Front 23

Echoes of ultrasound waves reflected from a boundary between two media will have the highest intensity when those two media are:

Back 23

b. Air and bone

Front 24

When temperature of ideal gas increases from 300 K to 360 K:
a) the velocity of random motion of gas molecules increases by 20%
b) the kinetic energy of the gas molecules increases by 20%
c) the velocity of random motion of gas molecules increases by ca. 44%
d) the kinetic energy of the gas molecules increases by ca. 44%:

Back 24

b) the kinetic energy of the gas molecules increases by 20%

Front 25

During T1 MRI the ventricals/horns will be:

Back 25

Dark (short TR and short TE)

Front 26

During T2 MRI the ventricals/horns will be:

Back 26

Bright (long TR and long TE)

Front 27

MRI: Another word for ” decay of transversal magnetization”:

Back 27

T2 relaxation

Front 28

Clinical MRI image represents: a) spatial distribution of tissues of different density b) spatial distribution of hydrogen nuclei in a body c) distribution of tissues with different penetration depth of electromagnetic waves d) distribution of magnetic permeability of body tissues:

Back 28

b) spatial distribution of hydrogen nuclei in a body

Front 29

Reflections of ultrasonic waves occur always at a boundary between
a) tissues of different density
b) tissues of different absorption of sound waves
c) tissues of different elemental composition
d) tissues of different acoustic impedance:

Back 29

d) tissues of different acoustic impedance

Front 30

Experimentally determined flow rate through a vessel was (20 ± 1) ml/s and the drop in pressure along the vessel was (10 ± 1) Pa. The absolute uncertainty in calculated resistance to flow is:
a) 75 × 10 3 Pa × s/m 3
b) 2×103 Pa×s/m3
c) 3.3 ×102 Pa×s/m3
d) 2 Pa×s/m3:

Back 30

a) 75 × 10 3 Pa × s/m

Front 31

In the ESR examination we measure:

Back 31

viscosity of the blood plasma (ESR stands for erythrocyte sedimentation rate and indirectly measures viscosity of blood plasma)

Front 32

In a process of isothermal expansion a work of 200 J was done by an ideal gas. It means that:
a) internal energy of the gas increased by 200 J
b) internal energy of the gas decreased by 200 J
c) the gas lost 200 J energy in form of heat d) the gas acquired 200 J energy in form of heat.:

Back 32

d) the gas acquired 200 J energy in form of heat.

Front 33

An object is placed at x= 10cm from converging lens and the lens focal distances is f=6. The image will be:

Back 33

50% bigger than the object

Front 34

The image of the near point is created on the retina when:

Back 34

The eye power is the biggest and the lens is strongly convex

Front 35

Maximal tolerable value for heart rate is about 210 bpm. Its period and frequency are given: (s + hz)

Back 35

0.28s and 3.5Hz

Front 36

Delta G = - 0.30 eV – spontaneous reaction?

Back 36

yes

Front 37

Delta G = + 0.24 eV – spontaneous reaction?

Back 37

no

Front 38

Density of compact bone is about 1.8 g/cm3 and the velocity of sound propagation is 4080 m/s. The acoustic impedance of bone is:

Back 38

b. 7.34 x 106 kg/(m2s)

Front 39

What kind of reaction: “Internal energy of system can be changed only if work is performed by or on the system”

Back 39

Adiabatic process

Front 40

A prolonged stay in high-temperature environment can be hazardous to people in particular when:

Back 40

when the air is humid

Front 41

The blood is considered as a “non-Newtonian” fluid. This means that:

Back 41

its viscosity is dependent of sheer rate

Front 42

An MRI image of a skull can reults in a dark area in the center and a white “brim” all around the skull – the difference in contatsts are due to:

Back 42

difference in effective atomic number and mass density of the structures

Front 43

The main interaction process responsible for heating of soft tissues by microwaves is:

Back 43

rotation of molecules having a none-zero dipole movement

Front 44

(MRI) an increase of TE parameter in the spin-echo sequence will lead the picture to be:

Back 44

more dark except “the horns/ventricals” in the middle that will continue to be bright

Front 45

In SPECT an isotope is introduced into a patients body and the examination is based on detection of the isotope radiation coming out of his body. This is possible only when the isotope is:

Back 45

gamma emitter

Front 46

The Doppler effect refers to:

Back 46

a change frequency of registered waves when the detector and the source are moving relative to each other

Front 47

How much water must be added to a vial with 400 ug of a medicine to obtain a final solution of 10^-3 g/l concentration:

Back 47

0.4L

Front 48

A sound wave of 3000 Hz frequency has loudness of 60 phones. If frequency of this sound increases to 6000 Hz without changing the intensity level (i.e. its energy) the perceived loudness of the sound will: a. Increase b. Increase twice c. Decrease d. Remain the same:

Back 48

d. Remain the same (this frequency change does not change perceived phones. However more dramatic changes may change the perceived loudness)

Front 49

Recently Holland introduced restrictions regarding levels of noise (or music) in public institutions (also pubs Discos concerts etc.). The highest allowed level is 103 dB, which is about 20 dB lower than the threshold of pain. It means, that the acoustic energy reaching the eardrum at 103 dB in comparison to that which causes pain is about:
a. 2 times lower
b. 20 times lower
c. 100 times lower
d. 200 times lower

Back 49

c. 100 times lower

Front 50

The frequency range of acoustic waves which we percept as sounds is (20 Hz -20 kHz). If velocity of acoustic waves in air is 340 m/s than the respective range of wavelengths is:
a. 59 mm-59 m
b. 17 mm-17 m
c. 59 m-59 mm
d. 17 m-17 mm:

Back 50

, d. 17 m-17 mm

Front 51

Consider a converging lens with f = 10 cm and object placed at object distance x = 25 cm. The image created by the lens is:
a. Magnified on the opposite side of lens
b. Diminished, on the opposite side of lens
c. There is no image (image is not created)
d. Magnified, on the same side of lens

Back 51

b. Diminished, on the opposite side of lens

Front 52

The Diopter (the unit of lens power) is equal to: a. Meter b. N c. 1/meter d. 1/meter2:

Back 52

c. 1/meter

Front 53

The astigmatic eye is corrected by using: a. Positive (converging) lens b. Toric lens c. Negative (diverging) lens d. Flat lens:

Back 53

b. Toric lens

Front 54

A lens has power D = 10 Diopters. If the image of an object has the same size as the object itself then the object – lens distance is: a. 0.1 cm b. 0.2 cm c. 0.1 m d. 0.2 m

Back 54

d. 0.2 m

Front 55

An increase in water content in a pathological tissue will affect its MRI image mainly due to:
a) increase in proton density of the tissue
b) increase in T1 and T2 relaxation times
c) decrease in T1 and T2 relaxation times
d) decrease of T1 and increase of T2 relaxation times:

Back 55

Increase in T1 and T2 relaxation times

Front 56

In ultrasonography the probe is covered with a gel before it is applied to the patient skin. The reason for this is:

Back 56

Elimination of the ultrasound reflections from air gaps between the probe and skin

Front 57

The motion of blood flowing through an artery sometimes can affect its image with medical imaging methods even without any additional procedures, dedicated to flow detection. This is true for

Back 57

:, MRI and Doppler ultrasonography

Front 58

Clinical MRI image represents:
a. spatial distribution of tissues of different density b. spatial distribution of hydrogen nuclei in a body
c. distribution of tissues with different penetration depth of electromagnetic waves
d. distribution of magnetic permeability of body tissues:

Back 58

b. spatial distribution of hydrogen nuclei in a body

Front 59

Two charges of opposite signs and of absolute values q=1C were placed at the distance of 20 cm. The dipole momentum of this system is:
a. 0.2 C and the sens of the vector is oriented in – to + direction
b. 0.002 C and the sens of the vector is oriented in – to + direction
c. 0.2 C and sens of the vector is oriented in + to – direction
d. 0.002 C sens of the vector is oriented in + to – direction:

Back 59

0.2 C and the sens of the vector is oriented in – to + direction (p = qd = 1*0.2 = 0.2. Dipole moment points from negative to positive charge)

Front 60

The physical basis of operation of clinical MRI machines is:
a. Different penetration of magnetic fields through different tissues
b. Absorption of radio-frequency electromagnetic waves by electrons
c. Absorption of radio-frequency impulses by hydrogen nuclei placed in magnetic field
d. Resonant absorption of energy of static magnetic fields by electrons:

Back 60

c. Absorption of radio frequency impulses by hydrogen nuclei placed in magnetic field

Front 61

Potentially hazardous physical factors during MRI are:

Back 61

c. Time-varying magnetic fields, radio-frequency electromagnetic waves, strong static magnetic field

Front 62

RQ formula =

Back 62

vol. CO2 / vol O2

Front 63

The value of basal metabolic rate (BMR) of an average person is approximately:

Back 63

80 W

Front 64

Thermal discomfort felt when being in a rain forest is mostly due to:

Back 64

Reduced heat losses to the humid air by evaporation

Front 65

Knowing the value of the respiratory quotient (RQ) one can:

Back 65

get information on type of food components used as substrates in cellular respiration

Front 66

If the temperature T increases the conductance G of the conductors type I (metal) and type II (electrolites) respectively will:

Back 66

d. I- decrease, II- increase
(Electrical resistivity of metals increases with temperature; conductance in eletrolytes increases with temperature)

Front 67

According to the second principle of thermodynamics:

Back 67

Real processes in isolated system cannot proceed towards macrostates represented by lower thermodynamic probability

Front 68

Vapor->water-ice : increase or decrease in entropy?

Back 68

Decrease

Front 69

Ice -> water -> vaper increase or decrease in entropy?

Back 69

increase

Front 70

An improved visualization of bladder in X-ray radiography using iodine compounds for contrast enhancement is related mainly to:

Back 70

Increase of effective atomic number inside the bladder

Front 71

What is the average blood flow in the aorta if stroke volume SV = 60 ml and heart rate HR = 100 beats/min:

Back 71

0.1 m3 / s

Front 72

The spreading out of molecules from a region their higher concentration is caused by:

Back 72

The random movement of molecules

Front 73

The reason for using high frequency acoustic waves (ultrasound) in medical imaging instead of low frequency audible waves is:
a) lower probability of potentially dangerous side-effects
b) better spatial resolution of images
c) better penetration in tissues
d) better contrast between different tissues

Back 73

c) better penetration in tissues

Front 74

The signal which is registered in PET imaging is caused by absorption of the following particles in the detectors:

Back 74

Positrons

Front 75

27. An interaction process(es) for the most part responsible for a high contrast between bone and soft
tissue in X-ray imaging is(are):
a) Compton scattering and photoelectric effect b) photoelectric effect and pair production
c) photoelectric effect d) coherent scattering

Back 75

c) photoelectric effect