Practice problems exam1 phys 272 PDF

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Practice problems exam1 phys 272...

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PHYS2 7 2

Exa m 1–Pr a c t i c ePr o b l e ms Pr o b l e m1 The magnitude of the electric field due to a small dipole is measured to be 100 N/C at a location on the axis perpendicular to the dipole and 2 cm from the center of the dipole. Approximately what is the magnitude of the electric field due to the dipole at a location 6 cm from the dipole along the same axis? 1. 2. 3. 4. 5. 6. 7.

100 N/C 0.41 N/C 37.0 N/C 900 N/C 11.1 N/C 33.3 N/C 3.7 N/C

Problem 2 The magnitude of the electric field due to a disk of radius 3 m and a uniformly distributed positive charge is measured to be 150 N/C at a location in the air 6 mm from the center of the disk, along a line perpendicular to the disk. Approximately what is the magnitude of the electric field due to the disk at a location 9 mm from the center of the disk, on the same line? 1. 2. 3. 4. 5. 6. 7.

44 N/C 67 N/C 100 N/C 150 N/C 225 N/C 338 N/C 506 N/ C

Pr o b l e m3 Th ema g n i t u d eo ft h et o t a lc h a r g eQo nt h edi s ki np r o b l e m 2i s 1 . C 2 . C 3 . C 4 . C 5 .No te n o u ghi n f o r ma t i o ng i v e nt od e t e r mi n eQ 1

Pr o b l e m4 As o l i dp l a s t i cb a l lh a sb e e nr u b b e da l lo v e rwi t hap i e c eo fwo o ls ot ha tn e g a t i v ec h a r g e i su n i f o r ml ys p r e a do v e ri t ss u r f a c e .Whi c hdi a g r a mb e s ts h o wst h ep o l a r i z a t i o no f mo l e c u l e si n s i d et h eb a l l ?

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Pr o b l e m5 T woa l umi n u m bl o c ks , Aa ndB, a r ei n i t i a l l yn e u t r a l . Th e yh a v ei n s u l a t i n gh a n d l e s , wh i c h a r en o ts h o wn . Th i ss e q u e nc eo fe v e nt so c c u r s :

Atat i mea f t e rt 4 , wh a ti st h en e tc h a r g eonb l o c kA? 1 .Po s i t i v e 2 .Ne g a t i v e 3 .Ne ut r a l 4 .No te n o u g hi n f o r ma t i o ng i v e nt ode t e r mi n ea na n s we r

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Pr o b l e m6 Wh a tl a wso rpr i n c i p l e swou l da l l o wy o ut od e t e r mi net hes i g no ft hec h a r g eo nb l o c kB a f t e rt i met 4? Pi c ka l lt h a ta p p l y . 1 .Th ePr i n c i pl eo fRe l a t i v i t y 2 .Th eMo me n t u m Pr i n c i p l e 3 .Th eSu p e r p o s i t i o nPr i n c i p l e 4 .Co n s e r v a t i o no fCha r g e 5 .Co u l o mb ’ sLa w

Pr o b l e m7 Yo uwi s ht oe s t i ma t et h ee l e c t r i cfie l dont h ea x i so ft h et h i nr i n gs h o wnbe l o w.I th a s r a d i u sR=5c ma n du n i f o r ml yd i s t r i bu t e dpo s i t i v ec h a r g eQ=1 0n C.Toma ket h e e s t i ma t ey o ud e c i d et od i v i det h er i n gi n t os ma l l pi e c e st h a ty o uc a na p p r o x i ma t ea spo i n t c ha r g e sa n d, t h e n , t oa ddu pt hec o n t r i b u t i o n st ot h er i n g ’ sfie l df r o me a c ho ft h ep i e c e s . Wh a tl a wso rpr i n c i p l e sa r ey o uu s i n gwh e nyo udot h i s ?Pi c ka l lt h a ta p p l y . 1 .Th ePr i n c i pl eo fRe l a t i v i t y 2 .Th eMo me n t u m Pr i n c i p l e 3 .Th eSu p e r p o s i t i o nPr i n c i p l e 4 .Co n s e r v a t i o no fCha r g e 5 .Co u l o mb ’ sLa w y

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Pr o b l e m8 I fy o ue s t i ma t et h efie l dd u et ot h er i n gi np r o b l e m 7b yd i vi d i n gt h er i n gi n t o6 0p i e c e s , e a c he x t e n d i n ga na n g u l a rd i s t a n c eo f 0 . 1 0 5r a d i a n sa r ou n dt h er i n g , wh a t c on t r i b u t i ond oe st h ep i e c eo ft h er i ngo nt h epo s i t i v eya x i sma k et ot h efie l da tt h e o b s e r v a t i o nl oc a t i o nc m? 1 .1 20N/ C 2 .0 . 0 1 2N/ C

5.N/ C 6.N/ C 3

3 .N/ C 4 .N/ C

7 .N/ C 8 .N/ C

Pr o b l e m9 Yo us t a nda tl o c a t i o nA, ad i s t a nc edf r o mt h eo r i gi n , a n dh o l das ma l lc h a r g e db a l l .Yo u fin dt ha tt h ee l e c t r i cf o r c eo nt h eb a l li s0 . 00 8N. Yo umo v et ol o c a t i o nB, ad i s t a n c e2 d f r omt h eo r i g i n , a n dfin dt h ee l e c t r i cf o r c eo nt h eb a l lt ob e0 . 00 4N. Wh a tob j e c tl o c a t e d a tt h eo r i g i nmi g h tb et h es o u r c eo ft h efie l d ? 1.Ap o i n tc h a r g e 2.Ad i p o l e 3.Au n i f o r ml yc h a r g e dr od 4.Au n i f o r ml yc h a r g e dr i ng 5.Au n i f o r ml yc h a r g e dd i s k 6.Ac a p a c i t o r 7.Au n i f o r ml yc h a r g e dh o l l o ws p h e r e 8.No n eo ft h ea bo v e

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