PHY 2049 A review 21 Coulombs law 22

PHY 2049: A review 21. Coulomb’s law. 22. Electric fields, vector superposition. 23. Gauss’ law, E due to various charge distributions 24. Electric Potential, superposition 25. Capacitors 26. Current and Resistance 27. Circuits

Tips • The exam will be held here during the usual class hours (12: 30 -2: 00 PM) on Monday June 6, 2011. • You are allowed a calculator, a #2 pencil and erasor and a single page formula sheet. The sheet must contain only formula. • Please bring your student ID. • Do not wear a hat in class during an exam. • Please do not use any electronic communication during the exam. • At this time, practice old exams.

Question • Four identical light bulbs A, B, C and D are connected in series to a constant voltage source. A wire is then connected across B. What is the brightness of A relative to its former brightness? • (1) 0. 44 (2) 0. 56 none of these (3) 1. 78 (4) 2. 25 (5)

• Two isolated conducting spheres are separated by a large distance. Sphere 1 has a radius of R and an initial charge 2 Q while sphere 2 has a radius of 3 R and an initial charge 8 Q. A very thin copper wire is now connected to the spheres. Charge flows between the spheres until they reach the same electrical potential. How much charge will be transferred from sphere 2 to sphere 1? (Note that the charge transferred can be positive, negative or zero. ) (1) Q/2 (2) 2 Q (3) –Q/3 (4) -3 Q (5) None of these

A Formula sheet