PMU - Year 1 Physics - Part 2

Descrição

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.
Sole C
Quiz por Sole C, atualizado more than 1 year ago
Sole C
Criado por Sole C quase 10 anos atrás
268
7

Resumo de Recurso

Questão 1

Questão
Which substances have both intrinsic, and extrinsic electric conductivity:
Responda
  • Conductors
  • Dielectrics (insulators)
  • Semiconductors

Questão 2

Questão
Dielectrics can be described as having:
Responda
  • Free electron states in the valence band
  • Wide (forbidden) band gap, and completely occupied valence band
  • Extrinsic atoms from elements with different valance

Questão 3

Questão
P-doping of semiconducting germanium (Ge), will create additional energy levels;
Responda
  • Near the conduction band of Ge
  • At the forbidden band-gap of Ge
  • Near the valence band of Ge

Questão 4

Questão
The band-gap width of a dielectric (insulator) is:
Responda
  • Narrower than 1 eV
  • Wider than 3 eV
  • Narrower than 0.01 eV

Questão 5

Questão
Band theory of solids defines conductors as having:
Responda
  • 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

Questão 6

Questão
N-doping of semiconducting germanium (Ge), will create additional energy levels:
Responda
  • Near the valence band of Ge
  • At the forbidden bang-gap of Ge
  • Near the conduction band of Ge

Questão 7

Questão
Valence and conductivity bans overlap partially in:
Responda
  • Metals
  • Dielectrics
  • Semiconductors

Questão 8

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

Questão 9

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

Questão 10

Questão
Current carriers in semiconductors are:
Responda
  • Holes only:
  • Electron and Holes
  • Electrons only

Questão 11

Questão
What type of current carriers are the holes:
Responda
  • Positrons
  • Unoccupied electron place-holders (virtual positive charges)
  • Positive Ions

Questão 12

Questão
How does intrinsic conductivity of semiconductors depend on temperature?
Responda
  • It increases with Temperature
  • It decreases with Temperature
  • It does not depends on Temperature

Questão 13

Questão
How does intrinsic conductivity of semiconductors depend on Temperature?
Responda
  • 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.

Questão 14

Questão
What are the current carriers in a P-N junction, upon application of forward bias?
Responda
  • Electrons and Holes
  • Only Electrons
  • Only Holes

Questão 15

Questão
Using OHM's LAW: In order to assess the medicinal effect of a substance, in dermatology, the skin impedance Z is studied by:
Responda
  • Electromagnetic Waves
  • An Alternating Electric Current
  • A Direct Electric Current
  • A Magnetic Field

Questão 16

Questão
The electric impedance of biological tissues is composed of:
Responda
  • R and Xc
  • XL and Xc
  • R and XL

Questão 17

Questão
Using OHM's LAW: Capacity reactance of an AC circuit is equal to:
Responda
  • wL + 1/wC
  • 1/wC
  • wL

Questão 18

Questão
Using OHM's LAW: The direction of electrical current fluctuates with time in:
Responda
  • One-way rectified current
  • Direct Current
  • Alternating Current

Questão 19

Questão
Using OHM's LAW: Ohm's law states:
Responda
  • U = IR
  • R = I/U
  • R = UI

Questão 20

Questão
Using OHM's LAW: Electric current is:
Responda
  • A flow of elementary particles
  • A flow of charged particles
  • An electromagnetic wave

Questão 21

Questão
The unit for electrical conductivity is:
Responda
  • Ohm
  • Electrical conductivity is a dimensionless
  • Siemens [S]

Questão 22

Questão
The unit for electrical resistance is:
Responda
  • Voltage
  • Ampere
  • Ohm

Questão 23

Questão
What type of tissue or body fluid have the highest electrical conductivity:
Responda
  • Cerebrospinal fluid
  • Blood Plasma
  • Blood
  • Skin and Bones

Questão 24

Questão
What is the frequency of direct currents (DC)
Responda
  • 50 MHz
  • 50 Hz
  • DC has no frequency

Questão 25

Questão
What type of electrical current is a lightning bolt?
Responda
  • Direct current (DC)
  • High Frequency AC
  • Low Frequency AC

Questão 26

Questão
What type of electrical current is a galvanic current?
Responda
  • High Frequency AC
  • Low Frequency AC
  • Low Direct Current

Questão 27

Questão
What type of electric impedance is present in the human tissue?
Responda
  • Inductive and Capacitive
  • Resistive and Capacitive
  • Resistive and Inductive

Questão 28

Questão
What type of electric impedance is present in the human tissue?
Responda
  • Direct Current Only
  • Alternating Current Only
  • Both, AC and DC can propagate
  • Neither, only electromagnetic waves can propagate.

Questão 29

Questão
Transducer is a device for:
Responda
  • Generation of metastable radionuclides
  • Transformation of energy from one form to another
  • Other name of linear scanner

Questão 30

Questão
What type of transducer is the piezoelectric crystal? (e.g. transducers in echo-graphs)
Responda
  • Generator type
  • Both Parametric and Generator Type
  • Parametric Type

Questão 31

Questão
What type of transducer is the ionization chamber:
Responda
  • Parametric type
  • Both Parametric and Generator Type
  • Generator type

Questão 32

Questão
Which of the objects mentioned below is a transducer:
Responda
  • Permanent magnet of MRI
  • Roentgen film
  • Geiger-Muller Counter
  • Mercury Thermometer

Questão 33

Questão
Which of the objects mentioned below is NOT a transducer:
Responda
  • The ionization chamber
  • The Roentgen Film
  • The Geiger-Muller Counter
  • The pressure gauge of the blood pressure measuring device

Questão 34

Questão
Which of the following functions are performed by a photocell:
Responda
  • 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.

Questão 35

Questão
Thermocouple is an arrangement of two different metals:
Responda
  • To convert heat into electric energy
  • To convert heat into chemical energy
  • To convert electrical energy into heat

Questão 36

Questão
Which of the following is NOT a transducer
Responda
  • The battery of cardiac pacemaker
  • The thermistor
  • The photoelectric cell

Questão 37

Questão
Which is the most relevant electromyography parameter for determination of damaged tissue
Responda
  • Rheobase
  • Chronaxie
  • Coefficient of accommodation

Questão 38

Questão
In an active electro-diagnostics the source of E.M.F (Electromotive Force):
Responda
  • The body of the examined patient
  • The electrocardiograph
  • The stimulation apparatus
  • The electroencephalograph

Questão 39

Questão
In a passive electro-diagnostics the course of Electromotive Force is:
Responda
  • The body of the examined patient
  • The Electrocardiograph
  • The Stimulation apparatus
  • The Electroencephalograph

Questão 40

Questão
ECG is a method of:
Responda
  • Examination of muscles
  • Examination of the brain
  • Examination of the heart

Questão 41

Questão
EEG is a method of:
Responda
  • Examination of muscles
  • Examination of the brain
  • Examination of the heart

Questão 42

Questão
EMG is a method of:
Responda
  • Examination of the muscles
  • Examination of the brain
  • Examination of the heart

Questão 43

Questão
The active electro-diagnostic differs from the passive one in the fact that source of Electromotive Force:
Responda
  • The electromyography
  • The examined organ in the patient's body
  • Apparatus used for electro-stimulation

Questão 44

Questão
The defibrillator is used to:
Responda
  • 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

Questão 45

Questão
The cardio-stimulator (the pacemaker) is:
Responda
  • 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.

Questão 46

Questão
The cardio-stimulator (the pacemaker) is supplied by:
Responda
  • Biogalvanic elements
  • Small battery installed beneath the patients skin
  • The cosmic radiation

Questão 47

Questão
For electrostimulation on an object to occur, a minimum threshold stimulus is needed. This electrical stimulus depends on:
Responda
  • Electrical pulse current
  • Electrical pulse duration
  • Both, current and pulse duration.

Questão 48

Questão
Faradization is a method for:
Responda
  • 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

Questão 49

Questão
Microwave therapy uses:
Responda
  • 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

Questão 50

Questão
The most suitable frequency magnetic field is used in:
Responda
  • 20 Hz
  • 20 kHz
  • 20 MHz

Questão 51

Questão
High Frequency magnetic field is used in:
Responda
  • Capacitive Diathermy
  • MRI Tomography
  • Inductive Diathermy

Questão 52

Questão
Deep heating of tissues (Therapeutic Diathermia) is applied using a high frequency current of the order of:
Responda
  • 0.3 - 5 Hz
  • 0.3 - 5 kHz
  • 0.3 - 5 MHz

Questão 53

Questão
High frequency AC is less harmful to the body than low frequency AC. This is because high frequency AC:
Responda
  • Increases exposure time
  • Passes through the skin without irritation
  • Changes ion polarization

Questão 54

Questão
Microwave diathermy uses frequency of 2.450 GHz. This frequency is:
Responda
  • Higher than microwave oven frequency
  • Lower than microwave oven frequency
  • The same as microwave oven frequency

Questão 55

Questão
What type of accident is most common during microwave diathermy:
Responda
  • Electrocution
  • Burning
  • Neuromuscular Stimulation

Questão 56

Questão
The most prominent effect of DC on the human body is:
Responda
  • 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.

Questão 57

Questão
Which of the following effects is NOT characteristic for AC
Responda
  • 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

Questão 58

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

Questão 59

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

Questão 60

Questão
Which therapeutic method causes deep tissue heating:
Responda
  • High frequency therapy using electric current
  • Thermovision
  • Deep roentgen therapy

Questão 61

Questão
UHF with high frequency electromagnetic waves (= GHz) are used in:
Responda
  • Faradizations
  • Diathermia
  • Microwave Therapy

Questão 62

Questão
Negative, light aeroions have:
Responda
  • A favorable effect on humans
  • A negative biological effect on humans
  • A favorable effect if they are attached to dust particles.

Questão 63

Questão
Positive Aeroions have:
Responda
  • A favorable effect on humans
  • A negative biological effect on humans
  • A favorable effect if they are attached to dust particles

Questão 64

Questão
The franklinization (electric shower) is a method in:
Responda
  • Thermal therapy using infared rays
  • Patient preparation for diagnostic imaging
  • Artificial aeroionotherapy

Questão 65

Questão
In the Franklilization (electric shower) the negative electrode is:
Responda
  • Connected to patients chair
  • Above patients head
  • On the stage where the patients has stepped

Questão 66

Questão
Favorable effect on the organism have:
Responda
  • Light positive aeroions
  • Light negative aeroions
  • None of the aeroions

Questão 67

Questão
The concentration of light, negative aeroions is higher in:
Responda
  • In the forest
  • Small village
  • Industrial Town

Questão 68

Questão
Iontophoresis uses:
Responda
  • US
  • Radioactive sources
  • Direct electric current
  • Alternating electric current

Questão 69

Questão
Iontophoresis is a method for:
Responda
  • Electrodiagnostics
  • Electrostimulation
  • Electrotherapy with drugs

Questão 70

Questão
During Iontophoresis, if active pharmaceutical ion is positive, the active electrode is:
Responda
  • The anode (positive)
  • The Cathode (negative)
  • Either anode with work

Questão 71

Questão
What is the difference between Sonophoresis and Iontophoresis:
Responda
  • 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.

Questão 72

Questão
The constant magnetic field applied to the patient in MRI examination is:
Responda
  • Weaker than the earths magnetic
  • Much stronger than the earths magnetic field
  • Equal to the Earths magnetic field.

Questão 73

Questão
What part of the hydrogen nuclei (protons) are examined tissues participates in the processes of forming a diagnostic image:
Responda
  • All protons
  • Minor part (about 0.0001%)
  • All protons from the water molecules.

Questão 74

Questão
In order to observe the phenomenon of Nuclear Magnetic Resonance (NMR), in an atomic nucleus must be:
Responda
  • Metastable
  • Radioactive
  • With a magnetic moment other than zero

Questão 75

Questão
The contrast between different biological tissues in MRI is obtained from:
Responda
  • The decay of electromagnetic waves, passing through them.
  • The difference in density p of tissues
  • The difference in volume concentrations of hydrogen nuclei (proton)

Questão 76

Questão
Medicinal Substances with anti-oxidation properties are analysed using:
Responda
  • Nuclear Magnetic Resonance
  • Electronic Paramagnetic Resonance
  • Radionuclide Methods
  • Colour Doppler

Questão 77

Questão
The chemical shift is an important parameter for direct observation of the chemical basis of disease, in:
Responda
  • SPECT - Single Photo Emission Computer Tomography
  • PET - Positron Emission Tomography
  • CT - Computed Tomography
  • Spectroscopic MRI

Questão 78

Questão
Which is the most common contrast substance used in MRI
Responda
  • 99m TC
  • 60Co
  • 64Gd
  • 10B

Questão 79

Questão
Volume Concentration of Protons is a parameter in diagnostic image formation in:
Responda
  • Technography
  • Magnetic Resonance Tomography MRI
  • Positron Emission Tomography - PET
  • Roentgenography

Questão 80

Questão
Contrast substances used MRI are:
Responda
  • Paramagnetic
  • Piezocrystals
  • Photosensitive

Questão 81

Questão
Contrast substances used in MRI diagnostics modify:
Responda
  • 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

Questão 82

Questão
Longitudinal time of relaxation T1 is a parameter used in:
Responda
  • Positron Emission Tomography
  • Echography
  • Magnetic Resonance Tomography
  • Roentgen Computed Tomography

Questão 83

Questão
Transversal time of relaxation T2 is parameter used in:
Responda
  • Positron Emission Tomography
  • Echography
  • MRI
  • Roentgen Computed Tomography (CT)

Questão 84

Questão
In MRI, the electric signals from different small volume elements (voxels) in examined tissues are distinguished by:
Responda
  • The applied gradient magnetic fields
  • Change in the frequency of the high frequency electromagnetic field
  • Introduction (injection) of contrast substance

Questão 85

Questão
The effect of the high frequency electromagnetic field on examined tissues in MRI is:
Responda
  • Dangerous heating
  • Insignificant endogenic heating
  • Electric Excitation

Questão 86

Questão
For which of the listed below organs and tissues, is MRI the most informative diagnostic imagine method:
Responda
  • Soft Tissues
  • Bones
  • Body Cavities

Questão 87

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