8/13/2019 New Minimum Requirement Questions for Biophysics
1/14Minimumrequirementquestions,2013/2014,page1
Contents1
Basicphysicaldefinitions............................................1
2 Atomicphysics,electromagneticwaves,Xray...........2
3
Absorption,luminescence,lasers...............................3
4 Geometricaloptics,microscopy,electronmicroscopy4
5
Nuclearphysics,radioactivity......................................5
6 Interaction of radiation with material, detection of
radiation......................................................................
6
7
Radiationbiophysics,
dosimetry,
biological
effect
of
radiations....................................................................
6
8 Experimental and diagnostic use of isotopes,
accelerators,gammacameraCT,PET,SPECT..............7
9 Basicprinciplesandapplicationsofnuclearmagnetic
resonance(NMR).Electrospinresonance...................7
10
Thermodynamics.........................................................
9
11
Diffusion......................................................................
9
12 Biologicalmembranesandmembranetransport.....10
13
BiophysicsoftheSensorySystem.............................12
14
Sound,Ultrasound....................................................13
15 Information and entropy, communication systems,
feedback
....................................................................
13
16 Modernmicroscopies,flowcytometry,sedimentation,
electrophoresis(Medicinestudentsonly).................14
1 Basicphysicaldefinitions
1. Define kinetic energy in words and with a formula,and give
its unit!Kinetic energy is the amount of work an object with amass
of m moving at a speed of vcan perform while itsspeed is reduced to
zero:
21
2
kineticE mv
The unit of kinetic energy is joule.
2. Define electron volt (eV)!Electron volt is a unit of energy.
It is equivalent to theamount of kinetic energy gained by a single
electronwhen accelerated through a voltage difference of 1 V.
3. Define what force is!Force is a vector quantity
characterizing the capabilityto cause acceleration.
4. Define acceleration in words and with a formula!Acceleration
is the rate of velocity change with time:
dv
a dt , wherea is acceleration, d
vis the change in
velocity in time t.
5. Define Newtons 2nd law in words and with aformula!The
acceleration of an object (a) is given by the ratio ofthe net (or
resultant) force acting upon it (Fn) and themass of the object
(m):
nFam
6. Define centripetal acceleration in words and with
aformula!Centripetal acceleration (a
c) is the rate of change in the
directionof velocity with time:2
2
c
va r
r , where vis velocity, ris the radius of the
path, is angular velocity.
7. Define angular velocity in words and with aformula!
Angular velocity () is the ratio of the angle (, usuallymeasured
in radians) traversed to the amount of time
(t) it takes to traverse the angle:
t
8. Define momentum in words and with a formula!Momentum (p) is
the product of the mass (m) and thevelocity (v) of an object:p
mv
9. Define moment of inertia in words and with aformula!Moment of
inertia (I) serves the same purpose incircular motion as mass in
linear motion. Itcharacterized the resistance of an object
againstangular acceleration, i.e. the change in angular
velocity.Moment of inertia of a point-like object can becalculated
by the following equation:
2I mr , where m is the mass of the object, r is thedistance of
the object from the axis of rotation.
10. Define angular momentum!Angular momentum is analogous to
momentum, itserves the same purpose in circular motion asmomentum
does in linear motion. By definition, theproduct of the angular
velocity and the moment ofinertia of an object is its angular
momentum.
11. Define the potential energy of an object in ahomogenous
gravitational field!The potential energy of an object with mass m
at aheight of h in a homogenous gravitational fieldcharacterized by
a gravitational acceleration of g isgiven by the following
equation:
potE mgh
12. Define the potential energy of a charged object inan
electrostatic field!The electrostatic potential energy of an object
withcharge Qat positionAin an electrostatic field is:
pot AE QU ,where UA is the electric potential at point
A.
13. Define work in words and with a formula!Work is the amount
of energy transferred by a force. Itcan be calculated according to
the following formula:
W Fs , where W is work, F is force and s is thedisplacement of
the object in the direction of the force.
14. Formulate the general form of the work-energytheorem, and
its special form for the electric andhomogenous gravitational
fields!
General form: 2 2, ,1
2kinetic B kinetic A B A AB
E E m v v W
, mis the mass, vBand vAare the speed of the object atpoint A
and B, respectively, WAB is the work done onthe object between
points A and B.
In an electric field:, ,kinetic B kinetic A AB
E E QU , Qis thecharge of the object, UABis electric potential
differencebetween points A and BIn a homogenous gravitational
field:
, ,kinetic B kinetic A ABE E mgh , hAB is the height
differencebetween points A and B.
8/13/2019 New Minimum Requirement Questions for Biophysics
2/14Minimumrequirementquestions,2013/2014,page2
15. Define power in words and with a formula, and giveits
unit!Power is the rate at which work is done, and it is
calculated according to the following formula: WPt
,
where Pis power, Wis the amount of work perform in
time t. The unit of power is watt ( J
Ws
).
16. Define the term and unit of voltage!
The voltage between points A and B is the differencebetween the
electric potentials of points A and B. Theunit of voltage is volt
(V). If the voltage between pointsA and B is 1V (UB-UA=1V), the
amount of work requiredto move a charge of 1 coulomb from point A
to B is 1joule.
17. Define electric current and derive its unit from otherSI
units!Electric current is the amount of charge transportedacross a
boundary per unit time. Its unit is ampere (A).
coulombA
second
18. Define resistance and give its unit!According to Ohms law
resistance (R) of a piece ofconducting material is the ratio of the
voltage appliedacross the piece of material (U) and the current
throughthe material (I):
UR
I
The unit of resistance is ohm ( V
A ).
19. Define what electric dipole is, and describe how tocalculate
its electric dipole moment!
An electric dipole is a separated pair ofpositive charge (+q)
and an equal amount of
negative charge (-q). The electric dipole moment (p) is
defined by the following equation:p q r , where ris the
separation distance between thecharges. Electric dipole moment is a
vector quantitypointing from the negative charge towards the
positiveone.
2 Atomicphysics,electromagnetic
waves,Xray
20. Give the energy and momentum of a photon withfrequency f.The
energy of a photon with frequency f is hf, and its
momentum is h f c h , where h and c arePlancks constant and the
speed of light in vacuum,respectively, and is the wavelength of the
photon.
21. What is the difference between the orbital and spinangular
momenta of an electron?- the orbital angular momentum originates
from theorbital motion of an electron; its magnitude depends onthe
shape of the orbital and the interactions of theelectron with the
surrounding particles.- the spin angular momentum is an inherent
property ofthe electron, its magnitude is independent of
thesurroundings.
22. Align in ascending order the following components
of the electromagnetic spectrum according to theirenergy:
microwaves, gamma, ultraviolet, visiblelight, X-ray, infrared,
radiowaves!radiowaves < microwaves < infrared < visible
light
