212
Exam Physics 1 practice problems
1)
Two
equally
chargedspheresofmass1.0gareplaced2.0cmapart.Whenreleased,theybegintoaccelerateat256
m/s2.Whatisthemagnitudeofthechargeoneachsphere?
A)
110nC
B)
91nC
C)
75nC
D)
59nC
2)
A
nucleus,whichhasachargee,issituatedtotheleftofacarbonnucleus,whichhasacharge6e.Which
hydrogen statementistrue?
A)
Theelectrical experiencedbythehydrogennucleusistotheleft,andthemagnitudeisequaltotheforce
force
exertedonthecarbonnucleus.
B)
Theelectrical experiencedbythehydrogennucleusistotheleft,andthemagnitudeisgreaterthantheforce
force
exertedonthecarbonnucleus.
C)
Theelectrical experiencedbythehydrogennucleusistotheleft,andthemagnitudeislessthantheforceexerted
force
onthecarbonnucleus.
D)
Theelectrical
force
experiencedbythehydrogennucleusistotheright,andthemagnitudeisequaltotheforceexerted
onthecarbonnucleus.
3)
The
electric
field1.5cmfromasmallobjectpointstowardtheobjectwithastrengthof180,000N/C.Whatisthe
object'scharge?
A)
-5.0nC
B)
+5.0nC
C)
-4.5nC
D)
+
4.5nC
4)
Whatis figurebelow?
the
magnitud
eofthe
electric
fieldat
the
position
indicated
bythedot
inthe
A)
3
6.3*10 N/C
B)
4.4*104 N/C
C)
1.0*104 N/C
D)
5
1.4*10 N/C
5)
Two4.0 cmelectrodesspaced2.0mmapartformaparallel-platecapacitor.Insidethecapacitortheelectricfield
cm4.0 strengthis2.5106N/C.Whatisthechargeoneachelectrode?
A)
35nC
B)
18nC
C)
16nC
D)
30nC
6)
The
equationfortheelectricfieldofanobjectwithanetchargeQcanbeexpressedusingE=kQ/r2
A)
ifanonlyifthe objectisapointcharge(likeanelectronorproton).
B)
iftheobjectis stationary.
C)
iftheobjectis
chargeortheobjectisauniformlychargedsphereand
risgreaterthanitsradius.
eitherapoint
D)
iftheobjectisa object.
theshapeofthe
7)
Acharged sphere,adisk,oraring.
E)
regardlessof initiallinearchargedensity.TheelectricfieldhasavalueofEatapointontheperpendicularbisector,
wireof atadistanceofx<<Lfromthewire.Whatisthenewvalueoftheelectricfieldatthesamepointxifthe
lengthL wireisstretchedtotwiceitsoriginallengthandthreetimesasmuchchargeisaddedtothewire?(Hint:
hasan
usetheinfinitewireapproximation)
A)
E
B)
3E
C)
3E/2
D)
2E/3
8)
An
longchargedwirewithuniformlinearchargedensity2.6710-6C/mrunsalongtheaxisofaGaussian
infinitely cylinderwhoselengthis75cm.WhatisthetotalelectricfluxthroughtheGaussiancylinder?
A)
0N 2/C
m
B)
Nm2/C
.26
2 105
C)
4.43106
N 2/C
m
D)
4.52105
N 2/C
m
9)
Whatis
the
electric
flux
through
the
surface
shown
below?
A)
N
1 m2/C
B)
1.73N 2/C
m
C)
2.2N 2/C
m
D)
0.6N 2/C
m
10)
Thenet
electric
fluxthroughaclosedsurfaceis1000N*m2/C.Whatisthetotalchargeenclosedbythissurface?
A)
8.85*10
-9
C
B)
1.77*10-8 C
C)
-8.85*10-9 C
D)
-1.77*10
11)
-8
C
Suppose electronmovesradiallyawayfromapositivelychargedhydrogennucleus.Doestheelectricpotential
an
energyofthissystemincrease,decrease,orstaythesame?
A)
Increase
B)
Decrease
C)
Stay the
same
12)
Consider potentialenergy?
thegroup
ofcharges
inthis
figure.
Allthree
charges
haveQ=
2.4nC.
Whatis
their
electric
A)
4.4106J
B)
.010
3
6J
C)
2.3106J
D)
4.1106J
13)
Aproton speedis1.3*106m/smovesfromonepointinspacetoanotherwhosepotentialhasincreasedby7kV.
whose
Whatisthenewspeedoftheprotonatthispoint?
A)
2.6106m/s
B)
8.6105m/s
C)
.910
5
5m/s
D)
1.3105m/s