PHS 212 Midterm with Solution, Spring 2005

NDU PHS 212 - Electricity & Magnetism Faculty of Natural and Applied Sciences Midterm Exam I - Spring 2005 Department of Sciences Duration: 100 minutes (1h40) 1. Two point charges sum to —5SpC C. Ata separation of 2 cm, they exert a force of 80 N on each other. Find the two charges when. a, The forces are attractive b. The forces are repulsive 2. Arod of length a whose ends are at (0,0) and (a,0) has a charge density A=( Qo) x (see figure) a a, Find the total charge Q on the rod. . 6.0 b. Find the force on a charge q at (-b,0). ¢ rhs ) 0 (2,0) me c. Verify that the force has the correct limitas b— co q Mm. Kaas Fag “a (eye 3. An infinetly long cylindrical shell of inner radius a and outer radius b carries a uniform volume charge density . Using Gauss' Law, find the electric field for r<a , a<r<b ,and r>b . 4. Acylinder, length J and radius R , carries a uniform charge density p . Its base is in the z~0 plane (see figure). Find the electric field (magnitude and direction) ‘at the point P on the z-axis (the axis of the | cylinder). \ Qu pa ae ¥ iis \ 2 ce) oo (at) ‘ o& V9 Sb es Ne v4 o> peh~ © F ea NOTRE DAME UNIVERSITY Zouk Mosbeh - Lebanon Name > ....... Course N° nau song SOCHON Foro al os ie Z Pod = a ice a mi —_ 7 cr SS ee | — Hall Meson —|-—|-— SEES Ses —a EAE =e ty : = = “ ; =< c v4 1 HE a ¥: 1% y came EEHAEREE as ing se uaerte v2 Dat | 1? | ' | | LL | } Taco fe Lt ae : erie rN i SOHO races ari oe me Wi x . SE “G ar = = § 3 a = Ss =I £ = vd ~ he) at G ay a) ap ~ a oa ro a < q “I = al is = ' | aul [ | & i i itt vm ) \) a © | | { Ry ; 7 fi ! i ! a BE ic Peers eee Pee peer] (cine 7 [ian ¢ ; : . D 1 ' ® 2 TRE : 7 Col eel GA 6 CE Bd EC | III: | N i | | im L al al | at ke THT) Bb be Bat a 8g PEELE PEST Pee ea net PUREE TEEPE GG Pee Ets PO RGORRRGe Mabe Re Ge man