PHYS7316 Graduate Quantum Mechanics
Homework set no. 3
Due February 4, 2015
1. Evaluate the following commutators:
a) Show that [Lz , p+ ] = hp+ , where p+ = px + ipy .
b) Evaluate [L2 , p+ ], [L2 , p+ ], [L2 , p+ ], and using these show that
Chapter 17: Light and Image Formation 1. When light enters a medium with a higher index of refraction it is A. absorbed. B. bent away from the normal. C. bent towards from the normal. D. continues in the same direction. Answer: C 2. Light is refracte
Chapter 15: Making Waves 1. Electromagnetic waves are generally A. transverse waves. B. longitudinal waves. C. a 50/50 combination of transverse and longitudinal waves. D. standing waves. Answer: A 2. The period of a sound wave is the A. end of the w
Chapter 13: Electric Circuits 1. A household circuit rated at 120 Volts is protected by a fuse rated at 15 amps. What is the maximum number of 100 watt light bulbs which can be lit simultaneously in parallel in this circuit without blowing the fuse?
Chapter 12: Electrostatic Phenomena 1. An electron situated near another electron would feel A. a repulsive electrical force. B. an attractive electrical force. C. a repulsive magnetic force. D. an attractive magnetic force. E. no forces from the oth
Chapter 11: Heat Engines, and the Second Law of Thermodynamics 1. The second law of thermodynamics says that the total amount of entropy, or randomness, in the universe cannot decrease. However, we see all around us objects that become more ordered -
PHYS 1030 FORMULAE
y y2 - y1 slope = = x x2 - x1
a= V (V - V0 ) = t t
V = V0 + at
V = gt
1 D = V0t + at 2 2
1 2 gt 2
FR = F1 + F2 + F 3 +.
FR = ma
F =G m1 m2 r2
Wt = mg
aC = 1 mV 2 2
FC = maC
Work = Fd
Chapter 18: The Structure of the Atom 1. For most elements, an atom has A. no neutrons in the nucleus. B. more protons than electrons. C. less neutrons than electrons. D. just as many electrons as protons. E. just as many neutrons as electrons. Answe
Chapter 8: Rotational Motion of Solid Objects 1. An isolated object is initially spinning at a constant speed. Then, although no external forces act upon it, its rotational speed increases. This must be due to A. an increase in the moment of inertia.
Chapter 6: Energy and Oscillations 1. Which of the following is not an energy unit? A. Nm B. Joule C. calorie D. watt E. kWh Answer: D 2. Work is not being done on an object unless the A. net force on the object is zero. B. object is being accelerate