[ur"o,R*=5o-or
tlq. Rn=
Ia
'61 : 6,0
Y-'
terieshaveemfs
:
V'
A; = 5.0v, and%3 4'o
resistor
fi"O (a) the currentin
2,
i, (t) thecurrentin resistor
uni i.; thePotentialdifference
Pointsa andb' ssm
between
Fig. z7'3tg Problem19,
9
- T r R , + € r = O + . I r = E eo- Z
foo
R,
= ,o . o5 4 .
b) r- TtRz + e r r - g a - F - 7= O
- 3
e+-,
€,
11 E
4= 5 o
Re
---
9
r - -
-
0.o6A.
v b -V " = - tt- e3
= , r D5 - + = , - q V
rr U5-Vi 3 ,,I,q-
s
C-!f
-
J =
or
I
I t
a
t
r
t
I t
^
v LD - v -A =
- 0.05x loo _4.
-qv
. , - q , , bI a R r 3 - 6 - 3 = - 1 V
(49) SwitchS in Fig.27-52is
closedat time t = 0. to begin
charging
an initiallyuncharged
capacitor
of capacitance
C :
15.0pcFthrougha resistorof
resistance
R : 20.0{}. At what
48
timeis the potentialacrossthe Fig. z7-5a Problems
and69.
capacitorequal to that across
theresistor?
, t
If--{^l-.
u.)
V c =€ ( . r -;
b
U*= I
R T-*, e
R :
RC
€
vc:,
Vf,
- Et c
*
)
=
(
r
e
ee
€
t
_ r/a,
ag
= l
t/rr.
U
=
l^(!)
+-e=
!
=-.0n1
t t - RC .Qn2.
-tl
b - _ 0 . 6 q R c: 1 . 0 6x l 0 s
tn an RC seriescircuit.i8 : 12.0V, R = 1.40M(), and
@
C = 1.80pF. (a) Calculare
thc rime consrant.
(b) Find the
maximumchargethat will appearon the capacitorduring
(c) How longdoesit tjrkefor the chargeto buildup
charging.
to 16,0;r.C?
R
r,.-I
c
z
T-T
a )T = R c = ! . 5 1 s .
a
b) 1*, 3 C e = 2 | 6. . pC (afl'e'
l*Eh")
:.
"t)
I
(t
ltt)= 1,*,
j
e/a.zz
l 6 p C =l l . 6 p c C t - .
,
-t6.sr
o.?t e l - e
e
?a.Ez
*.=
f-0.Pt:0. 16
- l n ( 0 s. 6 ) = - t . 3 s
t :' 3.tf s
@t
A capacitorwith initialchargeq1;is discharged
through
)7.ristor.fuhatmultiplcof thctime*nrtiiffi-iver thetime
takesto lose(a) the firstone-thirdof its charge
thecapacitor
and(b) two-thirdsof its charge?
Rc=f
fc
R
q ,3
1cr) 1"e
A. .nrhnl:
I+ hqs{r^il
t/ce
- e/ec
{
to".
a) .?.13
e
Jo
3
I.( v
''\
t
-Rc
t = Rcl^
q
I
(r)--o.t{| Rcu
- t/Rc
lntv
: o.{le
3 1 o . 1 o e
t . R c - 0 " 3 t . l R c = l .l G
-'.r.,.'A
Ri : 1oo
In Fia-.2i-12.
@
O,R"=Rr=50.0O.R4=
75.0 O, and the ideal batterY
hasemf E = 6.00V. (a) What
is the equivalentresistance?
1' (c)
What is I in (b) resistance
30
Fig.z7-42 Problems
3'
(d)
resistance
2,
resistance
and36.
4?
and (e) resistance
R,
^)
Rr.i= vot
=t
6J
t
Rar,f= lt'"53
R.r = ll8'?sJL
e--ur+o
b)
L
q
- o . o 5A
v t . I.,R.
.)
Ie.
=)
E = |
R'- 5o
J) Ie= i1 = 0 . 02 A .
e)
rr _ u
!
R+ ?5
- - o . o lA .
:o.orA
R''=50*,
'ttl. R',=tw'u,
= 6 0 V-'
terieshlve emfs €1
= 4.9 u'
%.,= 5.0V. and €3
in reslstor
Find(a) the current
1 (b) thecurrentln reslstor/'
uni t. f ,ft. Potentialdifference
ssM
betweenPointsa and '
Ir
Fig. 27-34 Problem19.
9
E
- T , R +,
€ l
= O
*
Iq:
Er 5
R, l o 0
0 . 05 4 .
TrR. + t , - t " - € 3 = o
rr=
€t - et- e3
^a
- 3
3- o.06A.
5o
9 v6-va=- Er- ot
5-+=-9V
tr Vr- Vi 3 - \ R , -
- 0 . 0 5 xl o O_r+
-qv
ot V5-Vq = - q - r . R r = - 6 - 3 - - - q V
-'-\-
of 100
A3E A capacitorwith dn initialpotentialdifference
them
whena switchbetween
V "-{t.t'u.g"9 througha resistor
across
is closdat r - 0. At r - 10.0s,thepotentialdit'furence
is 1.00V. (a) Whatis the time constantof the
the capacitor
acrossthecapaccircuit'/(b) Whatis the potentialdifference
itor at r - 17.0s?
^) vJ"=qg
=
'
C
-7*,
$c t%'=uo
fo
| : looe
-!-9
T
E
7
l ^ (\ I ' )
foo/
--- inloo
& too
Vc = lo0 e,
t?
l. r+
0 . 0 +v