ev dm e evd 2 m e 1 2 ev2 B) e 2 0 dm e D) m e

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1 . A paallel-plate capacito has sepaation d. The potential diffeence between the plates is V. If an electon with chage e and mass m e is eleased fom est fom the negative plate, its speed when it eaches the opposite plate will be: A) 2 ev2 B) e dm e ev dm e 2 ev m e evd 2 m e 2. In the pevious poblem, suppose that instead we had eleased a poton with chage +e and mass m p at est fom the positive plate. Compaed to the electon, when the poton eaches the opposite plate it will have: A) the same kinetic enegy and the same speed. B) geate kinetic enegy and geate speed. the same kinetic enegy and less speed. less kinetic enegy and less speed. less kinetic enegy and the same speed. 3. A point chage sits in the cente of a cube whose sides have length L. What is the electic flux though one face of the cube? A) 6 0 B) L2 4 0 L 2

2 4. A point chage of +4.8µC is located 0.77m fom a second point chage of.6µc. How much wok is equied to move the fist chage to a new location 0.2m fom the second chage? (Note: µc = 0-6 C.) A) J B) 0.2 J 0.88 J 0.24 J J 5. A solid insulating sphee of adius caies a unifom chage density ρ. Which of the following gaphs best epesents the magnitude of this sphee's electic field as a function of adius? A) B)

3 uestions 6 and 7 efe to the following cicuit: 5 Ω 6 V 3 Ω 6 Ω 6. How much cuent is dawn fom the battey? A) 3.2 A B). A 2 A 80 A 2.3 A 7. How much powe is dissipated in the 3Ω esisto? A) 5.7 W B) 7.0 W 26. W 3.5 W.7 W

4 8. Thee chages,, 2, and 3, ae aanged at the vetices of an equilateal tiangle as shown. The magnitudes of these chages ae not necessaily equal. When a positive test chage q is placed along the base of the tiangle midway between and 2, it expeiences a net electic foce F in the diection shown. 3 q F 2 What can you conclude about the signs of the chages, 2, and 3? 2 3 A) positive positive negative B)?? negative positive negative negative? negative negative positive? negative 9. A cicuit contains a esisto and a capacito C. At time t=0, the switch is closed. What is the potential dop acoss the capacito as t? V C A) V B) zeo V C V C V e t C

5 uestions 0 and efe to the following situation. A paticle of mass m and chage q entes a egion with a constant magnetic field B. The paticle's diection of motion is pependicula to the diection of the field. As a esult, the paticle undegoes cicula motion known as cycloton motion. 0. How long does it take the paticle to make one complete obit? A) mv 2 qb B) qb 4 0 mv qb mv 2 v qbm 2 m qb. How much wok is done on the paticle by magnetic foces in the couse of one complete obit? Assume that the adius of the obit is. A) qvb 2 B) mv 2 zeo 2 mv 2 qb m 2. Which of the following statements about ideal conductos is not tue? A) =0 inside the conducto. B) V=0 inside the conducto. The electic field just outside the conducto is pependicula to the suface. Any excess chage on the conducto esides on the suface. The suface of the conducto is an equipotential.

6 3. An aiplane is flying due east ove Ann Abo, whee the eath's magnetic field points in a diection between due noth and downwad. The skin of the aiplane is a conducting metal that contains some fee electons. What will happen as the aiplane flies though this magnetic field? A) lectons will accumulate on the left wing tip leaving the ight wing tip positively chaged. B) lectons will accumulate in the tail of the aiplane leaving the font of the aiplane positively chaged. lectons will accumulate in the font of the aiplane leaving the tail of the aiplane positively chaged. lectons will accumulate on the ight wing tip leaving the left wing tip positively chaged. No chage will accumulate anywhee on the aiplane because the aiplane is taveling pependicula to the ath's magnetic field. 4. Two pith balls with mass m ae suspended fom insulating theads. When the pith balls ae given equal positive chage, they hang in equilibium as shown at ight. We now incease the chage on the left pith ball fom to 2 while leaving its mass essentially unchanged. Which of the following diagams best epesents the new equilibium configuation? θ θ A) B) θ θ θ θ φ φ φ>θ β<θ 2 2 β β

7 5. A paallel-plate capacito is fomed fom two squae pieces of metal m on a side. The plates ae sepaated by m, and the space between them is filled with insulating ubbe, which has a dielectic constant of 6.7. When this capacito is connected to a 25-volt battey, what is the magnitude of the chage on each plate? A) C B) C C C C 6. A battey with intenal esistance int delives powe to a light bulb with esistance : negize Which statement is tue? A) The voltage appeaing acoss the teminals of the battey will not depend on int. B) The voltage appeaing acoss the teminals of the battey will not depend on. The powe geneated by the battey will equal the powe dissipated by the light bulb. The voltage dop acoss the light bulb will be less than the voltage appeaing acoss the teminals of the battey. The powe geneated by the battey is geate than the powe dissipated by the light bulb.

8 7. A paallel-plate capacito is connected to a battey, and chage is deliveed to the plates. The capacito is then disconnected fom the battey. What will happen if a dielectic slab is now bought between the plates? A) The capacitance will incease because the chage on the plates inceases. B) The capacitance will stay the same. The capacitance will incease because the potential diffeence between the plates deceases. The capacitance will decease because the potential diffeence between the plates inceases. The capacitance will decease because the chage on the plates deceases. 8. Only one of thee balls A, B, and C caies a net chage. One of the unchaged balls can become chaged by touching it to the chaged ball and then sepaating the two. This pocess of touching the two balls togethe and then sepaating them can be epeated ove and ove again, with the esult that the thee balls can take on a vaiety of chages. Which one of the following distibutions of chage could not possibly be achieved in this fashion? A) B) A B C

9 9. A bid lands on a bae wie that caies a cuent of 32 A. The wie has a coss-sectional aea of 0.3 cm 2, and is made of coppe, which has a esistivity of Ω m. Find the potential diffeence between the bid's feet, assuming that they ae 6.0 cm apat. A) 2.48 mv B) 7.52 mv 4.89 mv 9.54 mv 6.8 mv 20. In the figue below, two point chages have chages q =2 (>0) and q 2 =-. The points labeled p though p 5 lie along the same line as the chages and ae equidistant fom each othe and o the neae paticle. q q 2 p p p p p At which of the labeled points is the electic potential the geatest? A) p B) p 2 p 3 p 4 p 5 Befoe you go: ND OF XAM. Check you wok caefully. Make sue you have tansfeed all you answes to you scanton. 2. B SU YOU HAV FILLD IN YOU NAM, SCTION, UM-ID, AND XAM VSION NUMB ON YOU SCANTON. Failue to do these things coectly can esult in you gade being delayed o incoect. 3. Tun in you exam and you scanton at the font of the oom. xams will be etuned to you in you discussion section on Tuesday. Solutions to this exam will be posted on the couse web page by Monday.

Phys102 Second Major-182 Zero Version Monday, March 25, 2019 Page: 1

Phys102 Second Major-182 Zero Version Monday, March 25, 2019 Page: 1 Monday, Mach 5, 019 Page: 1 Q1. Figue 1 shows thee pais of identical conducting sphees that ae to be touched togethe and then sepaated. The initial chages on them befoe the touch ae indicated. Rank the