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(PHYS121)[2006](f)final~2678^_10005.pdf
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PHYS121 Fundamentals of Physics
Fall 2006
Final Examination

8:30 C 11:30am, 14/12/2006
LG1031

Important:

a)
Answer ALL questions. Total points of this paper is 100.


b)
This is a close book examination. You are not allowed to bring any book or paper to the examination room.


c)
Please put your student ID on the upper-right-hand corner of your desk.


d)
Please turn off all paging and telecommunication devices. You will be deducted 10 points if your device beeps. You will be disqualified if you use your device any time during the course of the examination.


e)
You can find a list of formulae below. Take a quick look through them before you start answering questions. You can detach this sheet for quick reference. Note that not every one of them is needed to answer this exam paper. If you need any formula not listed here, you can raise your hand any time during the examination. I will give it to you if appropriate.




---- Buena Suerte / Viel Glueck / Bon Chance / Good Luck / \ -----


Formulae:
NOTE: not every formula listed here is needed in answering this exam paper

Ideal gas law

Adiabatic process constant, = constant


Workdone by a gas W

Workdone by an ideal gas at constant T

Definition of specific heat

Molar heat capacities of an ideal gas

,
Change of internal energy of an ideal gas

First law of thermodynamics

Second law of thermodynamics

Entropy change C is the appropriate molar heat capacity



Efficiency of Carnot engine




capacitor: , energy density


with a dielectric,

inductor:
, energy density


Magnetic force on a charged particle

Magnetic force on a current carrying conductor


Biot-Savart law:


Maxwells equations:
Gauss law for electricity



Gauss law for magnetism



Faradays law of induction



Ampere-Maxwell law





where the displacement current


AC circuits:
Kirchhoffs laws: (i) algebraic sum of currents at a junction is zero
(ii) sum of potential rises and drops in any loop is zero
Potential drop across (i) resistance IR
(ii) capacitor q/C
(iii) inductor

Reactances
,

Impedance:

current:
(amplitude or rms)
phase angle:

Power dissipation:
, where cos
is the power factor

Constants:
Universal gas constant
J/mol.K
Boltzmann constant
J/K
Avogadros number molC1

Permittivity F/m

Permeability H/m

Speed of light in vacuum m/s
Question 1 (20 points)
Oxygen enclosed in a cylinder initially at a pressure of 2 atm , volume 4 L, and temperature 300 K, is used as a heat engine by the following four processes:

(i)
Heat at constant pressure from the initial state (state 1) to state 2, which has T = 450 K.


(ii)
C