f",
Name orsruden,,
h4*qld
&yozu
tLle:,b igpa;1:n S*-* rij
Physics Teacher:
Physics
A
OCR
AS S-vilabus H15B rePlacing
3BB3
Module: G482
Electrons, Waves and Pttotons
and
Exanr qttestions on electricity overlap the topic boundaries
than
so the selection of questions here may cover other topics
thst stated.
Topic: 2.3.7-2.3.2
't
Circuits
Including Kirchoff
These questions have been taken from recent papels up to 2A09,
based on specification 3883
The o1d specification is a close but not perfect match and some
parts of the new specification are not covered'
Remember a separate formul aldatasheet is available in the
examination. You may need to look at this to answer these
questions
For
Examina
Use
(a)ti}Placeatick{/)intheboxforanalternativeunitforthevolt.
JC
Js-l
JC-1
(ii)
u
T
V0
0^a-
Act otr$
l1l
The sta tement below is that for Kirchhoff's second law'
a circuit is equalto the algebraic
The algebmic sum of the e.m.f.s around a toop in
sum of the P.d.s around the looP'
Fig.5.1 shows an electrical circuit'
1.5
4.5 V
v
Fig.5.1
Use this law to determine the p'd' V'
o
Z
ar{ -- +'S - l'5^
= 3'c
i
V = $'O-O'*L
F
n
\J
JT.B
V_
2AzlJuNoz
3:8
v
[2]
For
Examine(s
Use
(b)
Fig.5.2 shows a potential divider circuit'
5.0v
!
Fig.5-2
battery may be assumed to have
The voltmeter has a very large resistance and the
negligible internal resistance.
of the LDR is 2'4kc')' The variable
For a particular intensity of light, the resistance
k{2'
resistor is set on its maximum resistance of 4'7
(i)
Calculate the reading on the voltmeter'
v* d;"""'::'n"'""'d{''
A = u/r-
NLq
=
8,+e-L C)
O lr- ;.^ =1.o+).rd\o6
tt"o
z t+'1 1S'9
[
ilt
'-
' 3'3\V O
(ii)
how the answer
I
- 3'3\
=
"u""1-"t"'readins="'"3':'3'
vtsl
to$fi)
changes when the light intensity is decreased'
. d-qcreo"a2,- O. nU- Ogp\nraho: .. d, -- ' "'
^gSd4
9""""'
tR k lDA ir*cxan"e5..- se...v'--'6esn>;""'tD
ftbO*. lt.f.\elgAr)1;).,.... .Y..ftcspg;- VA,*.4h!*.....
\C$:'nrr '= OA -q"t
-State
...... - .
. --
-- t1 l
.
[Total:7]
[Turn over
Fo
Exani
Us
Fig.3-1
X'
(i) Name the comPonent marked
4toet*^*h(, O
currents
(ii) Determine the magnitude of the
0
3\ tZ.o = 5\
3\ - z2)o tPt
=l
o
=a
t1l
1.,,
1, and 1,.
1.
=.......
.sl
.01
;,= 3 (t
,"=..... 'Afl-@
*n
mA
*o
[Total:6]
rul
Examinef s
Use
rconnected to a variable resistor'
Fig.3.1 shows a cell of e.m.f. Eand internal resistance
v/V
I El,r
t.u
1.2
I
0.8
l___-l
0.4
0
Fig' 3'2
Fig.3.1
y
terminals of the cell with the current
Fig.3.2 shows the variation of the p.d. across the
drawn from the cell.
{a)
V'
Explain how Fig' 3'2 shows that the e'm'f' E is 1 '4
(f,-,..:...1.f.,..**..",..'...'..'j.;":-':""""i""''';';-r'$'*""""
\
fl*t\ {
r*\
I
\! ' ,#
1
f .'.
u tt.'
p
'":""" '1''"::""""""Y{
""'l':"""""
t1I
.:..,..',r..iJ..::,s,:.,i.....i.....,.1,.....ir,....+.......,...............,,....;...,;.:;:.r,*.'..9=...'."""""'
(l
':: {3 's"
'"
l "'
;" - rii
''' '* 'i";
''
'
'
be crawn from
c.--.n
that
(i) use Fid.5.zio o"tulrinB th; maximum possible currenf
the cellt,:.,,r.-
1"-
l"r.,.l,u
i-. \,,._. :. , s*"1-
n
It'
Y
current = ............,*.1..."......'
(ii)
-
Calculate the internal resistance rof the cell'
-
/r
t
\t
A i1l
The statements below are either laws of physics or definitions of physical quantities or units. ln the
space provided, name the law, quantity or unit being stated.
(a)
The sum of the e.m.f.s in a loop of an electrical circuit is equal to the sum of the p.d.s in that
loop.
rhis is a statemen,
(b)
"t
The current in a metallic conductor kept at a constant temperature is directly proportional to
the potentialdifference across its ends.
/l\
This is a sratement of
(c)
.kifclrrhs$t...$4SSnfL. r"*.
.......Sh*^* .
rr*.
U
t1I
The potential difference divided by the current.
rhis is rhe definition tor ..f.€*hJ-gb*sr*
(d) The energy
transformed by an electron travelling through a potential difference of one volt.
rhis is the derinition
ror the
...€,1.L$,-CS*
.
m.il..f { V
U
I1l
fiotal:4]
o
I
I
I
llilffiilr
ilril
ililt ltilt ltil ililI ilil ililt til ilil
'!
it
r
tr
g
A
t*
ta
t;1
t*
l*
t{
o
f':-"*
t
ti
*-t t
\^
0 i',.*tf 'e c I
resistance wire
Fig.4.1
The battery has e.m.f. 4.5V and has negligible internal resistance. The resistance wire has
resistance 4.0f), length 15cm and cross-sectional area2.3 x 10-8m2.
(i)
Suggest how you can arrange switches
circuit has a total resistance of 12f).
S'
and 52 (e.9. opened or closed) so that the
')
f-r_
.......>r:.1...'.'l;.i**;,.,.)............Yi.i;T3....:',',=1*.'.*hr..-'F.........U.
"".'".'"""""'t,'
. .......
I
lililt |ilil illll il|il-90472121}',
fiilt lilil ilil| ilil| lill illl lill
......
i1l
calculate
(iii) When both switches are closed'
circuit
the total resistance of the
1
e
:A+A
€' Ru
R
:
.,L
r?-/-{tfl]-r +'o
2
o
I
ar OR: R.8t
€,.€r-
delivered bY the
the total electrical power
p=Ys0
-gf o
-E
rr'o '10
+ l'K'
3
batterY
fif
=o'hfirft tY
()"p,I-P sr f = 1\r *fq5
-L N 6.+oti
ro'qs4Drlt
_U'w
: l.rr{J":'*""""
A? Uir!
power
= --.'. .l
-{\," =,
t3l
the ratio
\ =YL
current in the 12fl resistor
the resistance wire
"wrent'ln
Vt^.o
/ lt-e-**-4
v/ry'o
y"
= o,33
l2'o
ratio =
e. 73
I
fTotal:1
rn over
lllllllllllilllllruuullu[llllllllllllllllllll
For
Examinet'
Use
Fig.4.1 shows an electrical circuit'
600f,
B
360f)
Fig.4.1
The battery has negligible internal resistance'
(a) Show that the current 1is 25 mA'
+
)oe]
€.
:
=
€'.t
B
:t=ya;#;*
tlL\ = 32el
O
u)ry
h+&
\ cr:t
so'li\a- \'o lt\-a#
6oD
I
[Turn over
(a) Fig. 4.1 shows
an electricalcircuit'
0.60A
1.8C)
Fig.4.1
the cell is
resistance r' The current drawn {rom
The cell has e.m.f. 1.5V and internal
resistance o{ the cell'
0"60 A. Calculate the internal
;i = .^ t* L;' 8- E-*,*f,:r@
l,r*f
^'***l..i--t'-l
G,Ur---,ry^.,,.,f
VilL\C
luwv'" I\tLl ^P "'
,-
=.f-tu
f.t{.-:'t,*
=,
_l.;
**,r=_
*.,-
=
j,.tJ
1
r..,
^-fL'
r=&Llcruo-}.;--otsl
(b)F\g.4.Zshowsafilamentlampandtworesistorsconnectedto"fd.c.supply.
20f)
12v,36w
12v
10f,
Fig' 4'2
resistance'
The d.c' supply has negligible internal
,12V, 36W,. Calculate the resistance of the filament
The {ilament lamp is rated as
(i)
' lamp when used in this circuit' ril^ .4t,: & ! t
.. t
- l flri'
?=o7e
c{
o
-|.
=:t.=
L-':'{;
- .,L ? .._+
,"f
R?UtPA
'*e,
'. rr
+
. f|
ra l-t : 5 ,f'- ^ \\ ,i
€
Jg'
a
$fup'
v
;i
t
;;:.*0
';*,
r
*r' .'.. .t2l O t2]
i-.--^^tf
,",1;tunce-= .........:i:.
I'
C"\''\ uT'ric\ ixqft"ccl"
I
[Turn over
For
Exaninefs
(ii)
calcutate the total resistance of this
cu(,b^l , ct
*^
h
'"- 3E: \Y
circuit-
1 Rn- : Sm t t]
4.- -F,
I
w K=-€.€r*
-\- g,rg'
R= *"L
fft
d+'.q- F
S.y3
resistance =........-*.:..fY....... r, t.t
R = 9*n
R'
s-^", :
g
R*
c,__
1
0
3* -'r*tr*
{iii)
Galculate the ratio
.
ll-
^
1a,r.g
?/
: Bb
= 3,c H
/g
-tn
lL
h
\,
= O.+oi}
: -l'5
.--\ \q
5*,* .ll
u)v
i'u*-rt*
current in the filament lamp
current in the 20 CJ resistor
't
: 3'e
rn
\-''
,
\j.La
!
ratio=......T.:.r
O
.' n,
[Totat: 10]
Use
-
For
Examinefs
Use
a sma* dryer used to brow warm
air.
rl
shows an erectricar circuit for
Fig.4.lshowsanetectricalcircuitforasmatldryerusedtoblowwarmatr.
Fig.4.1
\"
I
\
*":"andran
t\
motor and fan
--L
I
I
-.A={,ff""\l
I
;:JX
12v
':JT
I
of 2 oQ and 6 0"
\
L$1,ff'1?ifl?1Tl,T1,"1":lfi;lm*T*1[,j;:5'.""'"'.
|
(a)Calculatethetotalresistanceofthecircuitwithbothswitchesclosed.ll
ai\
k.*r*.=
,oG
R'
F.;.
=
= b't ^12.':u=
\'Ss-
I
the
I
,-o
i
""-"\-\
with onty switch A closed'
power dissipated by the coil X
resistance =
(b) catcutate
'+ i
\
t=:{=J'(=9eO
").0
a'a
0
power =
O_\
*fl,t.,
..-..:7'Z
unit
I
\l
fE,O \
\J
t4l
=
"""'
rr.,a:7,
\
\
I
2A22lJUNO2
[Turn over
|
I
I
For
Examine
I
Use
5 (a) (i)
ptace a tick
.JC
Js-l
JC-l
(ii)
{t}
inthe box for an alternative unit for the volt-
n
l
V
CI'9
h-cL
Oilt
0
11I
The s tatement below is that for Kirchhoff's second lawThe algebraic sum of the e.m.f.s around a loop in a circuit is equal to the algebraic
sum of the p.d-s around the looP-
Fig.5.1 shows an electrical circuit.
4.s
-z_
e
r*f
-
1.5 V
v
,<lL'J
-
3.o
= 2-g
l' ,
O
-
Qt' \J
U
'L
0
V_
.6
v
[21
I
5 (a) (i)
Place a tick
.JC
Js-l
JC_1
{ii}
l
{/J inthe box for an alternative
u
V
0
For
Examin
Use
unit for the volt.
Oot lrcP
CI'g
t1l
The statement below is that for Kirchhoff's.second law.
The algebraic sum of the e.m.f.s around a loop in a circuit is equal to the algebnic
sum of the p-d.s around the loap-
Fig.5.1 shows an electrical circuit.
i
!
1.5 V
4.5 V
Use this law to determine the p.d- V.
2r-.I = /f.s- ,'f .: 3'o 0
i
o'L
l.
i
0
V_
.6
v
[2]
three resistorsFig. 3.1 shows an electrical circuit including
Fig.3-1
of 20 ft.
(a) The variable resistor is set on its maximum resistance
Calculate the resistance
between Points
(i)
B and C
R
--)- r \
-L
RK,K.
R
.r- r!
-b
: €3l
- $o
c:
R.-
R-*€.-
-
Soleo
9o+sc
.U
resistance =
(ii)
i.g,-................ o [2]
A and C.
{-- f;'* R,.
'- rD+rL = LL
resistance=......-!*.:l "OI1I
(b)
and an e'm'f'
has negligible internal^resistance
ln the circuit shown in Fig. 3.1, the battery
carcurate the ammeter
set on iti rowest reslstance of 0 e.
5.0 v. The variabre resistor is now
reading.
t
t
'to.g='-"e-
s9- \u-g'**legi-*.
\t\fr\ L
J:" YK
&*L':
o ",rr-
D
3 \Q -ro)
{
t
J
}
-a
,s*
.1.-n
ic
reading =
*.9 fi
......*.-:fl{t-."'
"
"A
[Total:5]
ffurn over
I
llilll filil lllll ffi ffi
t2l
lllll
lllll lllll lllil llll llll
Both electromotive force (e.m.f-) and poiential difference (p.d.) may be defined as
'energy per unit charge'- With reference to energy transfers, state one major dif{erence
between e.m-f. and potential difference.
ry
(c) Fig. 5.1 bhows an electrical circuit in which the voltmeter has an infinite resistance.
O.BOA
Fig.5-1
Calculate
(i)
the current I in the
fJ
= o'8o
(ii)
the voltmeter reading
\r^
1B
f) resistor
-o'Zo
= O'60
= T.R
= O.
":
t\\
{<rO
\o'8
/(
r80
reading = ........1.Q.:P........
"
n,
For
Examinefs
Use
{iiii
the resistance of the diode
R=Yt
=Jgi
=
O .2-s
(iv) the power dissipated
"p
= -ln*f R. "j
dto&r-+fu"t1"*
by the diode-
t=lv=q=r'K0
-L
t = 0'lotT ('o
power=
.Q.:.3.{D
wt2l
flotal:
Question 6 is over the Page
a-
I
I
L
I
111
(a)
.F?s,r?
i,{r }
1
I
Fig.3.1
(i)
is not equal
The voltmeter has an infinite resistance. Explain why the voltmeter reading
to the e.m.f. o{ the batterY.
'*
1
,.
1.r,
\
ri t,.l"r'
:' {T'Ss. v-r
rx"si* r* - *..**OY
(i
i)
\6=
^
irilgffi
r
B*X*,""ffmt"+.e
voltmeter
resistance of wire X is four ti*". s,"lt", lrln
potential
the
to
calculate
reading is 6.0V. Use your knowledge of potential divider circuits
difference across the wire Y'
g.*^ fl
j1
A
t
rhe
\7
f)
ft,,tKtil '
..fu."
o *'* 0
ff+hK
€ i'?'1
CR
t)
r"l
'Jt :ht ."?
,7
tr'
t
{o='
Ji
I\L
?,"
L,S
n
@ ry \"ld \'zv
potential difference = .. .. . ......!.1.!.
A vo\ruc6 bPh\a 4:t
Sp-p-c^.J tc\)L - al\0".: Q \
ooc*zoos
t
oL[u^r
grffi
{* - PS, aAilfloili - Ii,,'r* ].qrt*.r']*rJ t"1*hf:**'
;:H*
.....tv- . . - . v
of, +'(V b
\o LU _.,-; X
'J
PA
t's"cl
I3l
(iii)
tw:-
- +v,
.)a1
.rfu;.)l
)
L-
,l,rr
[Total:
B]
Turn over
o ocR 2009
Fig. 1.1 shows an electrical circuit.
t)
il
l,
Fig. 1-1
potential difference
Fig. 1.1, show how a voltmeter may be connected to measure the
t1l
tf-t" component
W.ft"ri,tl
on
X-
""t*"
the position
state the effect, if any, on the ammeter reading when the ammeter is moved from
shown to position P in the circuit-
; ;";;'
(c) ;;",.';'-*"
";"";r:;;; ;,' ";;;;;";';;
"'
(i)
1
J
Name the comPonent X.
tbRf
HgU,t fuPsft-ds"k t.e-u\sW-O
;;;
"
t1l
is
State how the resistance of X changes as the intensity of visible light
(ii)
"'
increased
an
. I*,ubhne.* dscr-<ffi*a ia" ngXf lolcA*{3 in(}3r'Aqsl-rir
(iii)
State the range o{ the wavelength of visible
light'
U*
hrsl?:lntu'
*.
3:5;-;;,t1
.
I
ililil lllil ffillllll illll lilll lllllllill ilil lil llil
_*-, f^
(d)
component X
The current measured by the ammeter is 4.8 x 10-3 A when the p.d- across the
is 1.BV-
(i)
Calculate the resistance of component X'
(: LL+'
=,l.k,rro
\L}
resistance
(ii)
=
For a time interval of 30 s, calculate
1
-; *\
-F
.......-':.f..*................... f) [2]
N
38C
the charge passing through the ammeter
qb=I"e O
-yE
-3
FIL'
rh
\)
F
\-
'3. ' i -1"-I
charge
=
....J.:.IS.V
.-c
I3l
the electrical energy transformed by the component X'
2
*\ r
3
u+J
v;
f\t
l,[\{q''
\-' -l
t-t
=
,i*,
.
!*
j'"r
\rr,.\ r- i -E
r} =
L<-u
0I\&lJ
q*
U
.,4:.,-
;'" .{}*l
=
a-
,],
- ir..
energy
flotal: 13]
0
Qnu- = C OCSb
\^J
ffurn over
[-.-.
I
ffilll illil ilil Iilil ilil ililt illlt lllll ffiI llll llil
6
The statements below are either laws of physics or definitions of physical quantities or units. ln the
space provided, name the law, quantity or unit being stated.
{a}
The sum of the e.m.f.s in a loop of an electrical circuit is equal to the sum of the p.d.s in that
loop.
rhis is a statement
(b)
kic$h{{.l)
$f$aql
,"*. U
"r
t1]
sr
The current in a metallic conductor kept at a constan t temperature is directly proportional to
the potential difference across its ends.
This is a statement of
(c)
o
......,....0hf4s.
The potential difference divided by the current.
rhis is the definition for....t$hkq$Sg
(d)
.
law.
t1I
,n
U
i
l1I
The energy transformed by an electron travelling thrgugh a potential difference of one volt.
rhis is the derinition ror the ....g\eCh00* rfOlh..{..g.V
t
O
t1I
[-otal:4]
I
iltilt ililt iltil iltil iltililffi ililt ilil iltil til ilil
'334190906.
Fig.6.1 shows an electrical circuit'
//
J
Fig.6.2
lilrill lllll lllil
lll[ullll$llll
lllil lllil ilil
llil
Calculate the total resistance between points
A and B.
,
A*..*
.\-,--k
\.$ \c;
e.q\
,!*"tr*t-Fa
u
t
Io
g'
t.,,'
t\
(c)
t'€*e;ri
{..
{\t
96? q'
.*
frr_
!s
g
':f,€l
t'+*;*l;t.: r,c
*&
s*:*; * b'f, 0
u!,\ ".,;.,\E"r e
e'0
s 1's
0
c*
resistance = .,..1.1..*.......... kO
I3l
The circuit shown in Fig. 6.3 is used to monitor
the variation of light intensity in a room.
Fig" 6.0
The battery of e.m'f. 5.0v has negrigibre
internar resistance. The voltmeter has
a very large
resistance and it shows a reading ot\.ZV.Calculate
(i)
the potential difference across the 1 .5
ke resistor
(t)
A
potential difference
=
\v
...
*..:.5........ ".. V l1l
j.
[Turn over
I
lltilt Iilil tilil
ill{il|l,f[il,tjil
Iilil
ilfit
ilil
lill
(ii)
the resistance F of the component X'
t\F-*,W^oC )
?.R
K*ft*
,?
'.
,
.l
-l
vI
ft
{6
J
-f,- x 5'* D
i.L =
f;,+
+ i'+
-=
ff=
i's
[Total: 11]
j
t+.tt'*e*
v\I
\.
\i
r.l
tr-
\-u
T\\
3
\1 ;
o
i
t*
/\\
*,,>
r.(-
i)
F-
l)
.;- *i
c.'\"'s'-*
\
O-l
t*
t\
.t
4<&e
:rt
,.i
t*
,r1-*
\P
i'e
r:
I
*
:-
t r*;r
r
I
J
rqC,
o
.*5
l*t -t
.-.a
I >tC,'-}
t
J*'
:.-*'
{r,
I
o
lllilt ilffi lllil
lt[lllillllilllll
lllil ilil ltil
lllt
For
Exaninefs
3 (a) Calculate the total resistance
between the points X and Y for the circuit shown in
Fig. 3.1.
100f)
Fig.3.1
\_
R
So R=
-L+-I
R.
R'.
G'
R,tR,.
R", \ t0 K\20
t6o + \2-C
L=
\sD r.1)- =
o
=
m Cns q"
'l2.tr-.
'l
\
NL
,
ltu t r"bq-rd lcJu<:
I
Glw
\-/ ,
ANUrt
0
0
11>
resistance =
t-}2...........o
ral
Use
For
Exaniner's
Use
(b) lnthisquestion,onemarkisavailableforthequaliiyofwrittenCommunication.
a water bath
used to monitor the temperature of
circuit
thermometer
electrical
A simple
is shown in Fig. 3.2.
0
Quality of Written Communication [1]
[Total: 8]
a.
[Turn over
f,.
2 (a) On Fig. 2.1, sketch
the variation wit h temperature of the resistance of a pure metallic
conductor.
resistance
temperature/"C
100 letrlperalul
9.2.1
(b)
lzJ
Fig.2.2 shows a circuit used to monitor the changes in the temperature of a room.
Fig.2.2
The thermistor is connected in series with a resistor of fixed value 1200Q. The battery
has e.m.f. 5.OV and negligible internal resistance. Assume that the ammeter has negligible
resistance and the voltmeter has very high resistance.
o ocR 2007
ililt ililt ffiil
ilililililil ililt ililI.904721206-
ililt
ilililil fit
+*
*\
'{
$
't
+
\&
.I
tli
t
'L)
irr
i:
s
4
(i
i)
E
*
\'. s,\ ...3
rl
a,q- i\
R
F
H
H
\l
-r-
it
l}l
Ti
E
J.
tiH
\&
!i
tt
i3
n
ix
lj
u>Jr-\
--.\J
I -:>
t
H
zob
\-- )l
,|\
u
0
.ftr'
ItoTl
I,J
\"1c.-;
t
-:'5
r
/-\
\\i
r-i
i?
[Total: 9]
ii
ii
#:
in
fi
$
Ii
}{
i:1
i *. *l
-^*'!
II
t
fr =* h'\ rI\
\t'
IE
Fr-
ti:,ab
.'
t-
\'t
:r>
arlq
t
,x-?
*i
f:i
ni
}l
ii
{?
{.ri
:!l
5t
i!
#.1
#
#
#
f 't i
'!-*
t.r*
rf-
U
i1
x +r
I
lr-€"F
31
#
t:1
ai
#i
,a?
w
urn over
Ri
d;
is1
trt
r.+:
Fa
F.:
I
lillll llil llil llilHil!xlilJlll lllil llil llil llll
Fig. 5.1 shows a potential divider circuit designed as a touch-sensor.
Fig.5.1
The battery has negligible internal resistance and the voltmeter has infinite resistance.
(a)
Explain why the voltmeter reading is zero when there is nothing connected between the
contacts X and Y.
r....No rrr\rs$y.
Gn ise*rit)I gS*^ dcg,.'bi ..S n*h,sn/,
X...:jt...--.h......S..:ay....ocontact between X and Y, the voltmeter reading changes from
OV to 3.4V because of the electrical resistance of the skin. Use this information to
calculate the electrical resistance of the skin between the two contacts-
(b) When the finger makes
v"& {; o
R*R,
\log
* Rt =
(:
\bt
3.+ = \bE xs.o
R-t [u8
r S-o
a.+
&\1^ \bP
[Total:4]
4naL= &sD K-^'- @
= -?1.
\eeoPv
\
\c"L\c't nMl^oc[
[Turn over
A negative temperature coefficient (NTC) thermistor is connected across the terminals of a battery
of e.m.f. 6.0V and of negligible internal resistance. Fig. 3.1 shows the variation of current 1 with
time f from the moment the thermistor is connected to the battery.
1/10-3A
Fig.3.1
(a)
Calculate the power dissipated by the thermistor at time f = 0.
T*+*rt*-3
ff=3/ O
f = i# nr**h rc*?
= l'r-1
(b)
Q[.\
G
o
L.o"r
,?Ett.5
roon
I
llltil ilil lllil lllil lllil lllll lllll lllil lllll llil llll
- 5021 83308 -
(a)
A student is given three resistors of resistances 10 Q, 1 2Q and 22{1.
(i)
ta
Draw a sketch to show how all three resistors can be connected to give maximum
resistance. Calculate the maximum resistance.
Arrangement:
i=F#
6
_)
-
a()
r'
ts-
fi-"
n '*-I"-a
ed-
**-f*
q
-.*r
;A
Ej*
t*
{:-
;
;
s1^r\rA
Nvw
U
I)
\\- M
u')i{C'
r
K-i.Srshn' \DJcrar
nrt
nuEdec(
vt)
*j
/E
I
Calculation for maximum resistance:
{.
[\
A.-
*9
^/
,2
-'
<J )-
JY
maximum resistance
= ..."........"..........#l::....,............... O
121
Draw a sketch to show how all three resistors can be connected to give minimum
resistance. Calculate the minimum resistance.
\
C\5 Otrc,.u'{_.
\d
11
.)
'J
]
,2
\J
lJ/
L4
+.l
"r-"
O.
?
o)
v
/
4
1"
Calculation for minimum resistance:
A- {*;
I. rh.
F\'
I
z
l*
\-f
J
,.i
(
+F
-!-* -j r.sL
b*u*
'i.;
$*
\T, 1;
F-i
R= +'S']
+L*
-4- d+
fn
q
minimum resistance =
Lto"*
roo,
r
lllll lllll lllll illll lilll lllllill
ilililililt ililt il|il
.1
96548505"
' ]--\J
o
t3l
[Turn ou".
J
.fr :.y-..t......,..................
i;g[st
ffii$
ffis
(b)
\-/
resistance
different cyrindricar shapes. The putty has
some conducting putty is rnourded into
oiJoo *r'en it his length / and diameter d'
cylinders made from this putty'
Complete the tabie belJw for different
ffiffi
i#d
'#iffl
sg
1g€
trE
ffi,€
ffi.^Gt
ffiGl
#f'-,,€
it$Et
ffi
ffi
l3l
ffi
fTotal:8]
ffi
I
Fig. S.1 shows a potential divider circuit used to monitor the temperature of a greenhouse.
Fig.5.1
The thermistor T is a negative temperature coefficient type. The voltmeter is placed across the
resistor R. Describe andlxplain how the voltmeter reading changes as the temperature of the
greenhouse increases..
.
-
..[m. Senopnnsu.r*....'r $.henm$
..
I
.
**smns*. $
ililll illll ililllilil lilil lilll lllll lllll lllll llll llll
Jihsrm'.u]hf.
I
I
0)
(a) Fig.4.1 shows components
of an incomplete electrical circuit'
m*M")n St;rtr wi{\
\
parallel, may be
complete the circuit oi Fig.4.1 io show how both lamps, connected in
P'
lamp
in
the
I2l
current
lit using the battery. lnclude an ammeter to measure the
(b)
fan'
Fig.a.Zshows a circuit designed to monitor the speed of rotation of a small
5.0
2.2kA
fan blade
Fis.4.2
For
The batiery has negligible internal resistance. The output voltage V trom the circuit is
equal to the potentiat difference across the LDR. Fig.4.3 shows the variation of the
output voltage Vwith time t
v/v
Examiner':
Use
4.0
3.0
2.O
1.0
0
40
t/ms
l3l
(i
For the maximum value for the output voltage V, calculate
i)
1.
the potential difference across the 2.2 kO resi$tor
f :
r'!
't
-F" ::
g
:-
potential difference = .....,;,*:.:fl:...'.......
2.
the resistance of the LDR.
V
ill
I
3
3
.*
*
l*-
F'-*
1
E
F:
tf
:3
{
-&
R\"
V,rre :
.L.o
t" E -o"l
-si
''-.-
Q.--
,j
?Bz;,uno:
\ Ql 1tc= (D
over
ln this question, one mark is available for the quality of written communication.
Draw a circuit diagram to show how a light-dependent resistor, a voltmeter, a variable
resistor and a cell may be used as a potential divider circuit to monitor changes in the light
intensity in the laboratory. Explain the operaiion of your circuit and sugges"t a reason for
using a variable resistor.
O cofiac[' Clrc-",,.t'.
O Qo$etk sln.no=:
+ CTLINU ba*iet1
o"- ^
"cuLt'
O W e.r-co\rlcmission
u"b*..
*}r*
fg{trtutde#-
i.*r
g*S E >
oN5
r>\
b/
\WL-
0tqqn:rsa\cr''n
$
w*1,\e^
Quality of Written Communication [1]
[Total:9]
I