University Physics 2 Exam 4, Exams of Physics

Download University Physics 2 Exam 4 and more Exams Physics in PDF only on Docsity! CODE - AABDJE - PHY232C, Summer 2006 - Virtual University Physics 2 1 Exam 4 Name: Your code is: AABDJE Put your name here: Keep this exam CLOSED until advised by the instructor. Fill out the bubble sheet: last name, first initial, student number, section number and code. 60 minute long closed book exam. A two-sided 8.5 by 11 handwritten help sheet is allowed. When done, hand in your bubble sheet and your exam. Possibly useful constants:
ke = 8.99 × 10 9 Nm2/C2

0 = 8.85 × 10 −12 As/(Vm)
µ0 = 4π × 10 −7 Vs/(Am)
c = 3.00 × 108 m/s
e = 1.60 × 10−19 C
me = 9.11 × 10 −31 kg
mec 2 = 0.511 MeV
h = 6.63 × 10−34 Js
h = 4.14 × 10−15 eVs
hc = 1240 eVnm
σ = 5.67 × 10−8 W/(m2K4)
Wien’s constant = 2.898 × 10−3 Km
RH = 1.097 × 10 7 1/m
E0 = 13.6 eV
a0 = 0.529 Angstrom
1 eV = 1.60 × 10−19 J
1 AMU (1 u) = 931.494 MeV/c2 = 1.67 × 10−27kg
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• Field directly out of page CODE - AABDJE - PHY232C, Summer 2006 - Virtual University Physics 2 3 Exam 4 Name: 12 pt Select True or False for the following questions about radioactive decay.  In alpha decay, a neutron is emitted. 1. A© True B© False  In gamma decay, a positron is emitted. 2. A© True B© False  In beta decay, an electron or a positron is emitted. 3. A© True B© False 6 pt A projectile is observed during a very short time of 1.1 · 10−24 s? What is its minimum energy uncertainty in nJ? 4.A© 1.01 × 10−2 B© 1.26 × 10−2 C© 1.57 × 10−2 D© 1.96 × 10−2 E© 2.45 × 10−2 F© 3.07 × 10−2 G© 3.83 × 10−2 H© 4.79 × 10−2 7 pt If the binding energy per nucleon of a fictitious nucleus with Z = N = 90 is 7.4 MeV, what is its mass in u? The mass of a proton is 1.007276 u. The mass of a nuetron is 1.008665 u. 5.A© 171.00 B© 173.70 C© 176.40 D© 180.00 E© 181.43 F© 182.86 G© 186.52 H© 192.12 12 pt Select True or False for the following statements.  The speed of electromagnetic waves in vacuum is not pro- portional to their wavelength. 6. A© True B© False  Sunlight perpendicularly strikes two surfaces of equal area. One surface is a perfect absorber and the other surface is a perfect reflector. The force exerted by the sunlight on the absorbing surface is twice the size of the force exerted by the sunlight on the reflecting surface. 7. A© True B© False  A wire carries a steady current i=I0. There is no electro- magnetic radiation from the wire. 8. A© True B© False 7 pt What is the wavelength of radiation emitted when an electron goes from the n = 6 to the n = 5 level of the Bohr hydrogen atom? Give your answer in nm. 9.A© 7459.89 B© 9324.87 C© 11656.08 D© 14570.10 E© 18212.63 F© 22765.79 G© 28457.23 H© 35571.54 7 pt The age of a piece of wood from an archeological site is to be determined using the Carbon-14 method. The activity of the sample is measured to be 0.432 times the Carbon-14 activity of living plants. What is the age of the sample in years? (The half-life of the Carbon-14 isotope is 5730 years.) 10.A© 4.26 × 103 B© 4.81 × 103 C© 5.43 × 103 D© 6.14 × 103 E© 6.94 × 103 F© 7.84 × 103 G© 8.86 × 103 H© 1.00 × 104 12 pt Select True or False for each of the following state- ments.  In the quantum mechanical hydrogen atom, electrons in the n=2 orbit all have the same angular momentum. 11. A© True B© False  The work function of a surface determines the minimum intensity of light which will cause electrons to be emitted. 12. A© True B© False  If the temperature (in K) of a black-body increases by a factor of two, then the emitted power increases by a factor of two. 13. A© True B© False 12 pt For each statement below, select True or False.  When a diffraction grating is illuminated by white light, the first order maximum for yellow light is farther away from the central maximum than the first order maximum for blue light. 14. A© True B© False  Red light strikes two narrow slits and an inteference pattern is observed on a screen. As the distance separating the two narrow slits is decreased, the interference pattern observed on the screen will get wider. 15. A© True B© False  As the wavelength of light hitting a single slit is increased, the diffraction pattern observed on a screen will get wider. 16. A© True B© False