8/9/2019 IAS Mains Electrical Engineering 2004
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nd
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8/9/2019 IAS Mains Electrical Engineering 2004
3/14
cir
cuit
diagra
m
i(O-
)
""
5
A
mp.
sho
wn b
elow
with
initia
l c
urren
t
L o::
H
6
.)
u
(t)
T
R
;;::
8
n
1
iii}
th
e fre
quenc
y r
f iipon
se of th
e
s t - ?
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ove s
ystem
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b
y
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1
tfere
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ce
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ua
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:r(n}
""'a y(n -
I)
.;.
x(n)
.
SJ
o
ns
i d
er
Ow
sv
st em
is init
ia lv
i8 ;.
d.
I 0
(b)
\Vhat
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com ;nut
_at
ion c ir
cu i;
: s1:n
a
c
o,m
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mut u
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t t
oran
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P =
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(c) (
i} Dis
cuss
tr
i \ {
~ ? r \ ru
tli..: l
i
o n of
:he
abO '
-: r:xnrP S
.
.
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\ 11
1\ .
,, ,
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4 . :> .
.
\
. ~ -
\
8/9/2019 IAS Mains Electrical Engineering 2004
4/14
where
X t ~ j
r)
is
the frequency response oflhe sequence
x(nT), T
is
the sampling period and
X {j 0.) is
the
Fourier transform of t h c - ~
continuoustime waveform. lf
the analog frequency response
is
band
limited
to the
rangt : 0 i < :r'T wha
will
the rww rt>lation
be
:
1
2x(}=l2
(b) (i) Illustrate and compare speedcurrent and
motor
with
thai of series and shunt
motor.
0
(ii}
A 3-phase. 5 Hz, I G poic gencrnror with t
n ~ C t e d windings has 144 slots with 10 conduc
star
slot. Thf' flux/pole of 24.8
mWb is
sinusoi
8/9/2019 IAS Mains Electrical Engineering 2004
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qH1l
.
m
oto r
cu
rren
t is
con
t in
uou
s a
nd r
ip pl
e l're
e.
f
or
c c t i
i ( ~ f O
(lha
tion
d.c .
m
ach
ine
run
nin g
as
am
otor
)
and
for
afi
ring
ang
le o
=
6
0
and
rate
arm
atu
re
curr
ent,
l c u l
(i)
t
quE
,
i
i)
::;pee
d a
nd
ii i)
~ u p
p l y
p
owe r
i
acto
r.
20
1. (a
) i
) A
sin
usoi
dal v
ol
tage
so u
rce
is a
ppli
td
ro th
e
p
araii
P.t I
(C n
etw
ork
as
;how
n i
n t
lw
b
low
. Fi
nd
the
e1w
rgy
~ t o r
and
e
m ~ r
g y
di
ss ip
ated
in
th e
res
isto
r
om
th
e in
tecv
al
0
u
J
sl
ip
so t
i
nd
u
ct
i
on
m
ot
o
r.
~
1
(d
)
A
p
a ra
b
o
l o
id
al
re
fl
e
ct
or
a
n
t
:n
iH\
of
' .
na l
a
re
a
of
800
0
e
m
w
o
rk
s
a
t :
l G
H
z
. C
a
leu
la
t
th
e
~
~
m
wi
dt
h
t
l
t
w
ee
n
fi
rs
t
n
u
lls,
(
ii
ha
lf
i
w
id
t
h,
a
no
iii
) ga
in
o
f
th
e a
n
ten
n
a.
2
0
G
:a)
i
D t
a
s
ec
o
nd
-m
4
~
w
h
low
p
as
:s
fi lt
e
r w
it
h
c
u
t
of
f
rre
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ue
-
~
kl
l
z
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s
e
o
nl
y
S
a
l
en
a
n
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ey
r \
e t
wo
rk
co
r
.
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as
s
ho
w
n
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lo
w
:
R
1
8
8/9/2019 IAS Mains Electrical Engineering 2004
8/14
{
ii)
F
i
nd
th
e
im
p
u
ls
e
re
p
on
s
e
r
th
e
s
y
st
em
wh
o:
;e
tr
an
s
fe
r
f
un
c
ti
on
is
gi
ve
n
as
f
o
llo
w
s
;
H
:t
.)
I
-
r
c
o
s
0
.
z
I
r
7
w
h
ic
h
co
n
ve
r
gt
:S
I
z
i
r
it
s a
p
a
ir
of
p
o
i
a
t
z :
:::
r
.
a n
d
a
d
o
ub
l
e z
r.r
o
a
r
z
: ;:
0
.
I
2
b
)
I
t
is
de
s
in
)d
to
t
r
a
n
s
m
it
a
n
a
u
dio
signal
which has
a
b
a
n
dw
i
d
th
o
f
l
0
k
H
z
w
i
th
a
n
ou
t
p
ut
S
N
o
f
40
8/9/2019 IAS Mains Electrical Engineering 2004
9/14
b
etw
een
Hz
a
nd
15
ld
iz.
Th
ec
arr i
er
fr
eq
uen
cy
at
the
.
:>u
tput
i
s 108
M
Hz
an
d t
he
m
axi
mu
m
fre
qu
enc
y
devi
a-
li
3 =
GO
h
at
do
yo
u
un
de
rs
ta
nd
by
le
ad
c
om
p
e n
sa
D
raw
th
e a
pp
ro
xim
a
ie
B
od
e pl
ot
fo
ra
le
ad
n.
s a
t o
a s
u i
tab
le
c
on
tr
ol
s
ys
te m
f
or
a
mi
s-
SJ e
t
o i
nt
ro
du
ce
a l
ea
d
Q
f :35
c l
t
M
I
o
f
6.5
db
a
t
2.8
rad/s. What
will
he
tIH
transfe r
fu
nction
of
th is
lead
8/9/2019 IAS Mains Electrical Engineering 2004
11/14
compens:.uor that
will
satisfy tlw
a b o v ~
requirement '
1
20
(b) 1\
;>
MYA. kV
,,.,,erwratcH-
with
x
, 20 \,
is
u
conrwded
through
a transformer. line and a transformer
to
:1 hus 1h:n s u p p l i f ~ s three i d t ~ n t i c a l motors as shown
in
fig. hdow. Each motor
has
x ~ ~ 2:) \, and xci
30
h, on
a l ~ ~ t . , r :
o f ~
MVA.
G.G kV.
The three-phase rating o ihe
s t ~ p up 1ransforrm-r is .5
\1VA.
ll'GG kV with a l e ; t k a g < ~
n ~ < ~ c : u n c r : ~ of
o ~ ~ _ < H l ( ~ t h ~ ~ ~ of the step-down ; r a n s i o r m ~ r
ts ?:>
\1
V
bb;b.b
l\V wtth n leakage r e ~ e t < u H . : e of I0',.
Thr:;
hu:;
l ' ( l l t a g ( ~ at
t h f ~
rnoto '
is G. ) I
8/9/2019 IAS Mains Electrical Engineering 2004
12/14
h1brication of a
monolithic circuit
sh )w.n below :
2
8/9/2019 IAS Mains Electrical Engineering 2004
13/14
GH
z
un
da
1.
0
MW
p
ea
k
pow
e
ro
utp
ut.
I
f
the
a
nte
nn
a
dia
m
ete
r' i
s4
m
e te
rs,
th
e
rec
eiv
er
ba
nd
-wi
dth
l.G
M
Hz
an
d
th e
rece
ive
r
h
as a
10
d
B n
oi
se
fig
ure
,
wh
at is
its
m
a
xim
u
m
d ~ ~ t
o n
r
a ng
e
for
l
t a
20
SE
CT
IO
N
B
5.
S
ele
ct
an
y
TH
RE
E
of
t
h
e
fo l
lowi
ng
sta
tem
en
ts
.
read
themcareful
ly
a
nd
i
de
nt if
y
t
he co
rr
ec
t
and
the
in-
Co
'tec
t one
s
J
us tif
y
yo
ur
ans
w
e r us
ing
no
t
m
ore
th
a n
20
0
w
ord
s in
e
ach
c
a
se
:-
(
a)
L
atc
h i
su
se
d
a
t
in
pu
t a
nd
tr
ist
ate
is
u
s N
is
2
fi
d B
,
c
a
k
u
a
te
t
lw
r
e c
(
iv
e
r
p
o
o
ce
s
s i
n
g
g
a
in
a
no
th
e
S/
N
.
'
8
.
(
a)
\
V
ri
te
th
e
d
i
sc
r
e
te
f
o
rr
n s
o
f
P
.PI
an
d
D
is
cu
s
s
in
b
rie
f
o
(b) Exp
lai
n h'riefly the tech no -eco no
1
ges
a
n
d
d is
a
d
v
a
m
;
1
gP
s
o
f I
IV
D
C
t
r
an
s
m
is
s
io
f,
n
2
0
(c
}
E
x
p
la
in
o
n-
l
in
e r
ea
l
-
ti
m
e c
of
.
:
s
te
rn
fo
r
p r
o
t(
:G
io
n
o f
a
li
ne
.
D
r
a \
a
s
a
m
i
j
t
o
g
ra
m
n
o
w
d
i a
g
,am
.
20
;t..flf