PMU - Year 1 Physics - Part 2

Question 1 of 87

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Which substances have both intrinsic, and extrinsic electric conductivity:

Select one of the following:

  • Conductors

  • Dielectrics (insulators)

  • Semiconductors

Question 2 of 87

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Dielectrics can be described as having:

Select one of the following:

  • Free electron states in the valence band

  • Wide (forbidden) band gap, and completely occupied valence band

  • Extrinsic atoms from elements with different valance

Question 3 of 87

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P-doping of semiconducting germanium (Ge), will create additional energy levels;

Select one of the following:

  • Near the conduction band of Ge

  • At the forbidden band-gap of Ge

  • Near the valence band of Ge

Question 4 of 87

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The band-gap width of a dielectric (insulator) is:

Select one of the following:

  • Narrower than 1 eV

  • Wider than 3 eV

  • Narrower than 0.01 eV

Question 5 of 87

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Band theory of solids defines conductors as having:

Select one of the following:

  • An unoccupied (free) electrons states in the valence band

  • A narrow band-gap, and absence of free states in the valence band

  • impurities from elements with lower valence

Question 6 of 87

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N-doping of semiconducting germanium (Ge), will create additional energy levels:

Select one of the following:

  • Near the valence band of Ge

  • At the forbidden bang-gap of Ge

  • Near the conduction band of Ge

Question 7 of 87

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Valence and conductivity bans overlap partially in:

Select one of the following:

  • Metals

  • Dielectrics

  • Semiconductors

Question 8 of 87

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Charge carriers of certain type (n or p) will dominate in a semiconductor when:

Select one of the following:

  • The number of unoccupied electron states in valence and conduction bands are equal

  • The band-gap is large, and the valence band is completely occupied

  • Impurities with lower or higher valence are present

Question 9 of 87

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What is the difference between dielectrics and semiconductors, according to band theory of solids.

Select one of the following:

  • The number of electrons in valence band

  • Band-gap is greater or less than 3 eV in width

  • The number of occupied electron in conduction band

Question 10 of 87

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Current carriers in semiconductors are:

Select one of the following:

  • Holes only:

  • Electron and Holes

  • Electrons only

Question 11 of 87

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What type of current carriers are the holes:

Select one of the following:

  • Positrons

  • Unoccupied electron place-holders (virtual positive charges)

  • Positive Ions

Question 12 of 87

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How does intrinsic conductivity of semiconductors depend on temperature?

Select one of the following:

  • It increases with Temperature

  • It decreases with Temperature

  • It does not depends on Temperature

Question 13 of 87

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How does intrinsic conductivity of semiconductors depend on Temperature?

Select one of the following:

  • A narrower band-gap results in higher conductivity.

  • A narrower band-gap results in lower conductivity.

  • It does not depend on the width of the band-gap.

Question 14 of 87

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What are the current carriers in a P-N junction, upon application of forward bias?

Select one of the following:

  • Electrons and Holes

  • Only Electrons

  • Only Holes

Question 15 of 87

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Using OHM's LAW: In order to assess the medicinal effect of a substance, in dermatology, the skin impedance Z is studied by:

Select one of the following:

  • Electromagnetic Waves

  • An Alternating Electric Current

  • A Direct Electric Current

  • A Magnetic Field

Question 16 of 87

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The electric impedance of biological tissues is composed of:

Select one of the following:

  • R and Xc

  • XL and Xc

  • R and XL

Question 17 of 87

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Using OHM's LAW: Capacity reactance of an AC circuit is equal to:

Select one of the following:

  • wL + 1/wC

  • 1/wC

  • wL

Question 18 of 87

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Using OHM's LAW: The direction of electrical current fluctuates with time in:

Select one of the following:

  • One-way rectified current

  • Direct Current

  • Alternating Current

Question 19 of 87

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Using OHM's LAW: Ohm's law states:

Select one of the following:

  • U = IR

  • R = I/U

  • R = UI

Question 20 of 87

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Using OHM's LAW: Electric current is:

Select one of the following:

  • A flow of elementary particles

  • A flow of charged particles

  • An electromagnetic wave

Question 21 of 87

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The unit for electrical conductivity is:

Select one of the following:

  • Ohm

  • Electrical conductivity is a dimensionless

  • Siemens [S]

Question 22 of 87

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The unit for electrical resistance is:

Select one of the following:

  • Voltage

  • Ampere

  • Ohm

Question 23 of 87

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What type of tissue or body fluid have the highest electrical conductivity:

Select one of the following:

  • Cerebrospinal fluid

  • Blood Plasma

  • Blood

  • Skin and Bones

Question 24 of 87

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What is the frequency of direct currents (DC)

Select one of the following:

  • 50 MHz

  • 50 Hz

  • DC has no frequency

Question 25 of 87

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What type of electrical current is a lightning bolt?

Select one of the following:

  • Direct current (DC)

  • High Frequency AC

  • Low Frequency AC

Question 26 of 87

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What type of electrical current is a galvanic current?

Select one of the following:

  • High Frequency AC

  • Low Frequency AC

  • Low Direct Current

Question 27 of 87

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What type of electric impedance is present in the human tissue?

Select one of the following:

  • Inductive and Capacitive

  • Resistive and Capacitive

  • Resistive and Inductive

Question 28 of 87

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What type of electric impedance is present in the human tissue?

Select one of the following:

  • Direct Current Only

  • Alternating Current Only

  • Both, AC and DC can propagate

  • Neither, only electromagnetic waves can propagate.

Question 29 of 87

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Transducer is a device for:

Select one of the following:

  • Generation of metastable radionuclides

  • Transformation of energy from one form to another

  • Other name of linear scanner

Question 30 of 87

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What type of transducer is the piezoelectric crystal? (e.g. transducers in echo-graphs)

Select one of the following:

  • Generator type

  • Both Parametric and Generator Type

  • Parametric Type

Question 31 of 87

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What type of transducer is the ionization chamber:

Select one of the following:

  • Parametric type

  • Both Parametric and Generator Type

  • Generator type

Question 32 of 87

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Which of the objects mentioned below is a transducer:

Select one of the following:

  • Permanent magnet of MRI

  • Roentgen film

  • Geiger-Muller Counter

  • Mercury Thermometer

Question 33 of 87

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Which of the objects mentioned below is NOT a transducer:

Select one of the following:

  • The ionization chamber

  • The Roentgen Film

  • The Geiger-Muller Counter

  • The pressure gauge of the blood pressure measuring device

Question 34 of 87

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Which of the following functions are performed by a photocell:

Select one of the following:

  • It converts chemical energy into electrical energy

  • It converts magnetic energy into electrical energy

  • It converts light energy into electrical energy

  • It converts electrical energy into light energy.

Question 35 of 87

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Thermocouple is an arrangement of two different metals:

Select one of the following:

  • To convert heat into electric energy

  • To convert heat into chemical energy

  • To convert electrical energy into heat

Question 36 of 87

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Which of the following is NOT a transducer

Select one of the following:

  • The battery of cardiac pacemaker

  • The thermistor

  • The photoelectric cell

Question 37 of 87

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Which is the most relevant electromyography parameter for determination of damaged tissue

Select one of the following:

  • Rheobase

  • Chronaxie

  • Coefficient of accommodation

Question 38 of 87

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In an active electro-diagnostics the source of E.M.F (Electromotive Force):

Select one of the following:

  • The body of the examined patient

  • The electrocardiograph

  • The stimulation apparatus

  • The electroencephalograph

Question 39 of 87

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In a passive electro-diagnostics the course of Electromotive Force is:

Select one of the following:

  • The body of the examined patient

  • The Electrocardiograph

  • The Stimulation apparatus

  • The Electroencephalograph

Question 40 of 87

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ECG is a method of:

Select one of the following:

  • Examination of muscles

  • Examination of the brain

  • Examination of the heart

Question 41 of 87

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EEG is a method of:

Select one of the following:

  • Examination of muscles

  • Examination of the brain

  • Examination of the heart

Question 42 of 87

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EMG is a method of:

Select one of the following:

  • Examination of the muscles

  • Examination of the brain

  • Examination of the heart

Question 43 of 87

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The active electro-diagnostic differs from the passive one in the fact that source of Electromotive Force:

Select one of the following:

  • The electromyography

  • The examined organ in the patient's body

  • Apparatus used for electro-stimulation

Question 44 of 87

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The defibrillator is used to:

Select one of the following:

  • Replace the heart in operations of the heart

  • Restore the rhythmical contraction and relaxation of the different structures of the heart muscle (the myocard)

  • Support the cardiac output

Question 45 of 87

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The cardio-stimulator (the pacemaker) is:

Select one of the following:

  • Self-recording device for measurement of the pulse and blood pressure

  • Substitute of the heart in operations of the heart

  • Generator of electric impulses needed for the cardiac output.

Question 46 of 87

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The cardio-stimulator (the pacemaker) is supplied by:

Select one of the following:

  • Biogalvanic elements

  • Small battery installed beneath the patients skin

  • The cosmic radiation

Question 47 of 87

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For electrostimulation on an object to occur, a minimum threshold stimulus is needed. This electrical stimulus depends on:

Select one of the following:

  • Electrical pulse current

  • Electrical pulse duration

  • Both, current and pulse duration.

Question 48 of 87

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Faradization is a method for:

Select one of the following:

  • Electro-gymnastics using low frequency pulsed current

  • Therapy using high frequency electric current

  • Deep electro-stimulation with two interfering currents, with frequencies 2 - 5 kHz

Question 49 of 87

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Microwave therapy uses:

Select one of the following:

  • Electric field generated by an electric current with a frequency of 50 hZ

  • Magnetic field generated by a direct electric current

  • High frequency electromagnetic waves

Question 50 of 87

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The most suitable frequency magnetic field is used in:

Select one of the following:

  • 20 Hz

  • 20 kHz

  • 20 MHz

Question 51 of 87

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High Frequency magnetic field is used in:

Select one of the following:

  • Capacitive Diathermy

  • MRI Tomography

  • Inductive Diathermy

Question 52 of 87

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Deep heating of tissues (Therapeutic Diathermia) is applied using a high frequency current of the order of:

Select one of the following:

  • 0.3 - 5 Hz

  • 0.3 - 5 kHz

  • 0.3 - 5 MHz

Question 53 of 87

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High frequency AC is less harmful to the body than low frequency AC. This is because high frequency AC:

Select one of the following:

  • Increases exposure time

  • Passes through the skin without irritation

  • Changes ion polarization

Question 54 of 87

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Microwave diathermy uses frequency of 2.450 GHz. This frequency is:

Select one of the following:

  • Higher than microwave oven frequency

  • Lower than microwave oven frequency

  • The same as microwave oven frequency

Question 55 of 87

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What type of accident is most common during microwave diathermy:

Select one of the following:

  • Electrocution

  • Burning

  • Neuromuscular Stimulation

Question 56 of 87

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The most prominent effect of DC on the human body is:

Select one of the following:

  • Constant orientation of ions (polarization), followed by accommodation

  • Continuous change of polarity and lack of accommodation

  • Vibration of ions around equilibrium position, rotation of electrical dipoles

  • Propagation through skin with irritation.

Question 57 of 87

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Which of the following effects is NOT characteristic for AC

Select one of the following:

  • Constant orientation of ions (polarization), followed by accommodation

  • Continuous change of polarity and lack of accommodation

  • Vibration of ions around equilibrium position, rotation of electrical dipoles

  • Propagation through the skin without irritation

Question 58 of 87

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Which of the following effects is characteristic for low frequency (50 Hz) alternative current:

Select one of the following:

  • Constant orientation ions (polarization), followed by accommodation.

  • Ions vibrate around equilibrium position, electrical dipoles rotate

  • Passes through the skin with irritation and causes deep heating

Question 59 of 87

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Which of the following effects is characteristic of high frequency (2 MHz) alternative current:

Select one of the following:

  • Constant orientation ions (polarization), followed by accommodation.

  • Ions vibrate around equilibrium position, electrical dipoles rotate

  • Passes through the skin without irritation and causes deep heating.

Question 60 of 87

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Which therapeutic method causes deep tissue heating:

Select one of the following:

  • High frequency therapy using electric current

  • Thermovision

  • Deep roentgen therapy

Question 61 of 87

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UHF with high frequency electromagnetic waves (= GHz) are used in:

Select one of the following:

  • Faradizations

  • Diathermia

  • Microwave Therapy

Question 62 of 87

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Negative, light aeroions have:

Select one of the following:

  • A favorable effect on humans

  • A negative biological effect on humans

  • A favorable effect if they are attached to dust particles.

Question 63 of 87

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Positive Aeroions have:

Select one of the following:

  • A favorable effect on humans

  • A negative biological effect on humans

  • A favorable effect if they are attached to dust particles

Question 64 of 87

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The franklinization (electric shower) is a method in:

Select one of the following:

  • Thermal therapy using infared rays

  • Patient preparation for diagnostic imaging

  • Artificial aeroionotherapy

Question 65 of 87

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In the Franklilization (electric shower) the negative electrode is:

Select one of the following:

  • Connected to patients chair

  • Above patients head

  • On the stage where the patients has stepped

Question 66 of 87

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Favorable effect on the organism have:

Select one of the following:

  • Light positive aeroions

  • Light negative aeroions

  • None of the aeroions

Question 67 of 87

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The concentration of light, negative aeroions is higher in:

Select one of the following:

  • In the forest

  • Small village

  • Industrial Town

Question 68 of 87

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Iontophoresis uses:

Select one of the following:

  • US

  • Radioactive sources

  • Direct electric current

  • Alternating electric current

Question 69 of 87

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Iontophoresis is a method for:

Select one of the following:

  • Electrodiagnostics

  • Electrostimulation

  • Electrotherapy with drugs

Question 70 of 87

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During Iontophoresis, if active pharmaceutical ion is positive, the active electrode is:

Select one of the following:

  • The anode (positive)

  • The Cathode (negative)

  • Either anode with work

Question 71 of 87

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What is the difference between Sonophoresis and Iontophoresis:

Select one of the following:

  • The former is therapeutic and the latter is diagnostic

  • The external (physical) stimulus, enabling the insertion of drugs into the tissue

  • The location of application.

Question 72 of 87

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The constant magnetic field applied to the patient in MRI examination is:

Select one of the following:

  • Weaker than the earths magnetic

  • Much stronger than the earths magnetic field

  • Equal to the Earths magnetic field.

Question 73 of 87

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What part of the hydrogen nuclei (protons) are examined tissues participates in the processes of forming a diagnostic image:

Select one of the following:

  • All protons

  • Minor part (about 0.0001%)

  • All protons from the water molecules.

Question 74 of 87

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In order to observe the phenomenon of Nuclear Magnetic Resonance (NMR), in an atomic nucleus must be:

Select one of the following:

  • Metastable

  • Radioactive

  • With a magnetic moment other than zero

Question 75 of 87

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The contrast between different biological tissues in MRI is obtained from:

Select one of the following:

  • The decay of electromagnetic waves, passing through them.

  • The difference in density p of tissues

  • The difference in volume concentrations of hydrogen nuclei (proton)

Question 76 of 87

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Medicinal Substances with anti-oxidation properties are analysed using:

Select one of the following:

  • Nuclear Magnetic Resonance

  • Electronic Paramagnetic Resonance

  • Radionuclide Methods

  • Colour Doppler

Question 77 of 87

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The chemical shift is an important parameter for direct observation of the chemical basis of disease, in:

Select one of the following:

  • SPECT - Single Photo Emission Computer Tomography

  • PET - Positron Emission Tomography

  • CT - Computed Tomography

  • Spectroscopic MRI

Question 78 of 87

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Which is the most common contrast substance used in MRI

Select one of the following:

  • 99m TC

  • 60Co

  • 64Gd

  • 10B

Question 79 of 87

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Volume Concentration of Protons is a parameter in diagnostic image formation in:

Select one of the following:

  • Technography

  • Magnetic Resonance Tomography MRI

  • Positron Emission Tomography - PET

  • Roentgenography

Question 80 of 87

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Contrast substances used MRI are:

Select one of the following:

  • Paramagnetic

  • Piezocrystals

  • Photosensitive

Question 81 of 87

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Contrast substances used in MRI diagnostics modify:

Select one of the following:

  • The size of the external magnetic field

  • The density of protons p in the examined tissue

  • The times of relaxation T1 and T2 in the examined tissues.

  • The frequency of the high frequency electromagnetic field

Question 82 of 87

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Longitudinal time of relaxation T1 is a parameter used in:

Select one of the following:

  • Positron Emission Tomography

  • Echography

  • Magnetic Resonance Tomography

  • Roentgen Computed Tomography

Question 83 of 87

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Transversal time of relaxation T2 is parameter used in:

Select one of the following:

  • Positron Emission Tomography

  • Echography

  • MRI

  • Roentgen Computed Tomography (CT)

Question 84 of 87

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In MRI, the electric signals from different small volume elements (voxels) in examined tissues are distinguished by:

Select one of the following:

  • The applied gradient magnetic fields

  • Change in the frequency of the high frequency electromagnetic field

  • Introduction (injection) of contrast substance

Question 85 of 87

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The effect of the high frequency electromagnetic field on examined tissues in MRI is:

Select one of the following:

  • Dangerous heating

  • Insignificant endogenic heating

  • Electric Excitation

Question 86 of 87

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For which of the listed below organs and tissues, is MRI the most informative diagnostic imagine method:

Select one of the following:

  • Soft Tissues

  • Bones

  • Body Cavities

Question 87 of 87

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MRI coil magnets operate at very low temperature (in liquid helium) so that:

Select one of the following:

  • The risk of tissue damage is reduced

  • The constant magnetic field is homogenous

  • A superconductivity is achieved - Magnetizing coil wires are very thin.

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PMU - Year 1 Physics - Part 2

Sole C
Quiz by , created almost 2 years ago

All Questions uploaded word for word from MCQ book. All Credit to Authors. Mistakes due in process may have been made, use and check your work at your own discretion. Only simple writing allowed, i.e Superscript and Subscript absent. Questions missed due to Figure/Diagrams/Text: 15. 16. 23. 24. 34. 77.

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Sole C
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