electrostatics - time
TRANSCRIPT
8/11/2019 Electrostatics - Time
http://slidepdf.com/reader/full/electrostatics-time 1/4
T.l.M.E.
TrtumDhant
ln€fftrtB
cf
trltanae€mdnt
Education
PvL
L d'
TEST
in
PIIY$CS
Ref
:
RTP62l2l4
SECTION
A
Integer
Answer
TYPe
Questiilns
I
'4:
Mark
the
con€ct
answer
to
friese
;;;;;
in
ttre
data
column
Provided'
No
negativema*ing
4x4={6
t.
Three
posiNe
point
charses
q'2:ltl
1.jli-3
r've'wrr"-
F-'
rtices
of
an
equilateral
are
Placed
at
the
vg
-r-.r- ^r
rha
ffi"fi;
;id;
".
rhe .n'asliY::.-:t,i1"
figure
0n radian)
uli'r$.v
vr
'mced
bY
a
charge
is
F'
ma:<imum
force
exPene
-
r
--.-L^
,aF
Time
:90
min'
Marks:105
3.
A
solid
non-conduding
spherc
Tlo
a
-'
.
unibrmly
distributed
cfiarge'
Find
the
ralio
of
the
elecfosbtic
energy
stored
in
tre
feld
outside
the
sPhere
to
thatinside
the
sphere'
1"
Gertain
quantity
of
positive
cfiarge
is
no*untficrmly
distibuted
over
a
thin
ring
of
raoius
f,
rnetre
as
per
linear
drarge
density
r,
=
6r)"in[".*1)
c
m-1'
wriere
0
is
as
per
Find
the
work
done
6n
rr'J)
by
the
field
forces
in
disptacing
a
point
drarge
ot
I
nC
fiom
the
cenfie
of
the
ring
to
infinitY'
SEC'TION
B
Single
Correst
Answer
TYPe
Quetions
5
'
19:
This
sec{ion
contains
15
;;;
with
only
one
conect
arsrrer'
iiark
JifV
o*
choice
on
the
oillR
sheets'
Marking
iol
n"n
one
answer
will
be
deemed
as
an
inconect
rcsponse
and
ONE
mark
will
be
deduc@d.
15x3=4S
5.
?-
-
- -
-
-
-
+-et
- -
-'-
--
-
-
-
Q+-o-
--
-
-
oP2
Force
on
a
short
dipole
of
moment
[]
due
to
a
short
dipole
of
moment
I
is
OireaeO
bnards
(a) up
(b)
dotrn
(c)
left
(d)
right
iuil'*"""r
poini
charse
q
q
T?:s|l.-f:l
i;ilS'.iii.ttacea
at
the
cenfioid
of
the
tdangte
;;;*
work
equai
,,
ffi'
Find
x'
2.
I
I
t
I
Figure
shows
an
infinite
line
of
uniform
charge
""T
"
o"*
cFrarge
at
psint
P'
Nor
the
point
charge
is
given
a
velocitY
vo'
Gase
(i)
lf
vo
is
direcled
perpendicular
to
the
plane
of
ffi;*
point
charge
reaches
point
P
again
aftertime
h.
Case (ii)
lf
vo
is
on
the
plane
of
paper
and
directed
i"d""i,*"r
to
ine
infinite
line'
of
charge'
the
;;ilil"*
reacies
point
P
again
after
reaching
a
maximum
Oistance
r
from
the
wire'
lf
*
=
**,
find
r
in
cm'
(Here
e
is
the
base
of
./e
natural
log?nftm)
8/11/2019 Electrostatics - Time
http://slidepdf.com/reader/full/electrostatics-time 2/4
A unibrm
infinite
line
of
charge,
an
equilateral
tiangle
of
side
1
m
and
a
point
p
are
all
ophnar.
The
work
done
in
moving
a
test
charge
from
P
to
any
of
the
three rrerticee-of
the
triangle
is
same.
Norr
a
uniformly
drarged
dng
is
ptaid
oplanar.
The
rrcrk
done
in
movin
the
test
cfiarge
bad<
to
p
is
same
inespeAtve
of
the
vertex
it
is
morred
fiom.
Then,
thE
distance
of
the
cenfiedthe
ring
to the
line
of cfrarge
is
(in
m)
o,#
o+
G,+
tg
D1e
to
a
point
drarge
located
somerrvhere
on
ry
plane,
the
potentials
at
p
and
e are
1
V
and
2
V
respectively.
Also,
the
diredions
of
electric
field
at
&ese
poinb
arc
at right
angles
to
eadr
other.
Then
ff
PQ
=
Jdm,
the
potential
at
midpoint
of
PQ
is
ralfv
tcl
-lv
J6
or
f,v
(d) none of the
abore
10.
The
elec{rostatic
fietcl
in
ry
plane
is
given
E=ry2i+g2j
ff,"
typical
representation
lines
of
force
in
the
ftrst
quadrant
of
ry
plane
is
(a)
.,
e
by
of
v
7.
&
@:
+z
ABcDEF
is
a
regutar
hexagon
on
*yiqn"
nm
1..:"'
/
{
f
,
B
parallelto
x
axis.
Due
to
a
uniform
E
in
me
x
region,
Vo
=
Vr
(V:
potential);
Also,
positive
work
.. F _,
-
needs
to
be
done
by
extemal
"g"rit
t"
,"""'"
11'
E
at
a
point
due
to
a
short
dipole makes
an
negalive
lest
cfrarge
ftom
A
to
e.
rn"n,
ntli
ansle
$
rad
wittr
its
dipole
msnent
The
acute
among
the
follorving
coutd
be
E?
(a)
eo
(i+60
(b)
Eo
(i_6i)
rcra
ei+r6i)
fiff-,f
::: i'*
o
Eo
(-i-.6il
(c)
tan-1;l;
(d)
cot-r#
9.
The.etedrostatic
field
in
ry
plane
is
given
by
12.
_
v'30v
ve15V
E=ft2v'i*vtrr)
,u
c,,
a,'rin
#;;:
il
fl K.--l
F]
work
done
by
extemal
agent
in
moving
a
test ,,{
4w
3
$F
Lr"^
foc
;iryffi+l
x
10i c
rirom
(0'0)
to
tril
i'
r'i
-=L
(a)
+1
,:-';'
v
\""
:
+
*-'
-5
O)
-*
S"witches
sr,
Sz
and
Ss
are
ctosed
ii
tr,ut
oro"r.
(").3
.,-3
:#ffi:;"+i.1',ili,ffiT,1H3's,;rnJq
(a)
108
(b)
10s
(c)
15
(d)
21
Triumphant
t".tft,fr"
Tel:040"278981%/115
Fax
: ffr2784?3f4
cnrll
, inroot*a"ao.ai--.#;.;;,
*,,*.qre4education.com
.*t"62t2t*2
8/11/2019 Electrostatics - Time
http://slidepdf.com/reader/full/electrostatics-time 3/4
13.
The apptied
F.d
E is
(a)
4.75
(b)
s.2s
(c)
5.25
(d)
6.2s
14.
The
rt/ork
done
by
a
battery
in
cfrarging
two
identicat
capacitors
in
parailetis
ttre
sar;
i"
U,"
uork
done
by
it in
cfrarging
them
in
series
but
ater
inserting
different
dielecftics
in
nem.
Hor
many
of
the
following
values
can
be
the
higher
of
the
two
dieledric
constants?
2.5,3.25,3.75
(a)
None
(b)
ene
(c)
Two
(d)
three
(a)
oi
is
unibrm,
o6
is
unibrm
(b)
oi is
uRihrm,
oo
is
non_unibrm
(c)
q
is
non-unibrm,
oo
is
unibrm
(d)
q
is
non-unibrm,
oo
is
nonuniform.
18.
A
is
a
solid
conducting
spftere
of
radius
R.
B
is
a
hollon
conducting
sphere
of
inner
Edius
r
and
outer
radiue
R.
A
canies
+q
dnrge
and
B
has
nil
charge.
A
and
B
are
far
***oC
*om
eactt
other.
Now
they
are
inGr
connected
Oy
a
long
wire.
Then
the
surface
cfiarge
Oenstty
*
n"
inner
surface
of B
is
(o)+
(d)
none
of
thse
R
;f,I
t-
E
volt
(a)
Zero
o#
i3
voll
{5"
A
hollow
conducting
sphere
witfr.
no
charge
loyor
a
pointdtarge
located
otr_centre
hde
hollovv.
lf
c
and
o0 represent
the
induced
surface
durge
densiti*
on
the
inner
and
outer
surh;s
respedively
of
the
hollow
sphere,
then
19.
ABC
is
an
equitaterat
triangle
with
its
ptane
perpendicular
to
an
infinite
plane
of
unibrm
charge
densrty
o
and
base
dc p""iel
t
*,"
plane.
Wor{<
done
in
modng
a
unit test
,f,urg"
along
each
of
trro
sides
AB
orAC
of
tre
Gngb
is
equalto
W.
The
side
of
the
tiangte
ls
equatto
€,;*
*,;+
'
The
time
constants
of
the
ttro
cirurits
ere
sagne
and
thesoules
are
ideaL
Ttlen
fr
n
F)
;
{n,
*
@,t
1.2
(d)2
A
large condueting
phte is
given
a
cfiarye
+q
and
kept
normal
to
a
uniform
fieH
E
"nJ
tn"n
earthed.
SECTION
C
Reasoning
Type
This
sedon
contalns
+
reasodig
typc
quetions
numbercd
Z0
b
23.
Each
guasffon
eonlins
ff*
P-liflg"noicee
(a),
(b),
(e|
and
tcl,
i,rrii*rri"r,
ONLY
oitE
is
conecr
oNE
mark
wiii
G
cJu*t"o
foreach
wxtng
answer.
{a}
STATE*IENT.I
is
Tnre,
STATEffiENT.2
is
True;
STATEIIdENT.Z
le
a
coneet
explanaiion
fioTSTATEMENT-i.
(bl
STATEITTENT-|
is
True,
STATEilEHT-Z
is
True;
STATEiIEI{T.A
ig
NOT
u
**"t
explanation
for
STATEffi
ENT-i.
(c)
STATEMENT.I
Is
True,
STATEtrEI{T-Z
is
False
The
efrarge
frat
flows
to
earh
is
{a)
zero
(b)
non-zero,
less
than
g
(c)
q
(d)
morethan
q.
(c)
z",E5U
6
{d}
sTATErrrEr{T-l
True
20.
STATEIiENT_
I
(q
4wqo
{3o
Is
False,
S?ATEFJEE {T-E
is
4x3={?
q>
+q
il
il
il
Ll--,
:
+
7.
lf
L
is
a
closed path
in
a region
containing
a
point
charge,
hen
uork
oone
in
taking
a
;J
&;;"
along
any
part
of
the
path
L
enn&
Oe'zero.
.
and
STATEMENT-2
JE.
A,
=0
tur
a
dosed path,
wfiere
E
is
the
eledrostatic
field.
&farao
lx'[l$:ffi
d
:040-2789&94D5
Far
:
g$-2?842334
cmait
:
websitc:rvrrw.time4education.com
RIP62U14t|
8/11/2019 Electrostatics - Time
http://slidepdf.com/reader/full/electrostatics-time 4/4
21-
STATENf,ENT-
t
ln a
region
of
etec{rostatic
field two
points
lying
on
two
different
lines of
force
cannot
be
equipotential
and
STATEMENT-2
Tangent
at a
point
on
a
line
of
force
(along
with
the anow
direction)
gives
the
direction
of
E
at
that
point
22. STATEMENT.-1
Afterfully
drarging
a
capacitor,
if a
dielectric
slab
is
introduced
Case
(D
with the battery
disconnected
Case'(i)
wtth
the
battery conneded,
then,
the
gain
in
electrostatic
energy,
stored
in the
capacitor
in case
(i)
is more
than
the
loss
of the
same
in
case
(t)
and
STATEMENT-2
ln case
O
the energy
for the
work
done
when
the
dielectric
is
moved
in,
is taken
trom
the
initially
stored
energy
white
in
case
(ii)
the
energy
is
drawn
from the baftery.
23.
STATEMENT-I
ln
a region
of
eledrostatic
field
caused
by
an
infinite
plane
of
charge,
if a test
charge
is moved
with
the same @nstant
and
uniform
speed
via
any
path
and
fiom
any
point
to
any
point,
the
instantaneous
power
is same
for
all
paths
for all
points
and at
all
instants of
motion.
and
STATEMENT.2
Forplaneof
charge,
E
andtherefore
F
issame
at all
Points.
Section
D
Multiple
Gorrect
Choice
TYPe
Queetions
24
-
28= This
section
contains
5
quesiions.
Each
question
may
have
ONE
or
MORE corect
answ€Gt.
ln
order
to
secute
marks
for
a
given
question,
ALL
conect
choiceq
and
OlrlLY
the
conect
choices
must
be
chosen.
No
negative
marking.
5x3=15
1-..
,-
24.
ln the
set
up shown,
a
dielectric slab
of dielectric
constant
K
and
having
dimensions
exactly
fitting
the interspace
between
the
plates
is
introduced
to
a distance'a'within
the
interspace.
Then:
The force
experidnced
by the
dielectric
is
independentof
the distance
moved
in
The force
experienced
by the
dielec{dc
is
propodional
to
'a'
i.e.,
the
distrance
moved
in
lf
the
inside
surface of the
plates
is smooth
and
the
plates
are rigidly
fixed, the
dielectric
will execute
periodic(non-SHM)
oscillations.
period
of
oscillations
is
proportional
to
Jt-a
Three
metal
plates,
all
identical,
are
placed
as
shown.
Plate
B canies
a charge
+Q
while A and
C
are uncharged.
Subsequently
switches
Sr and
S2 are
closed.
Then
closing
Sr
and
Sz)
inside
surface
ota
is
-$
lnitially
cfrarge
on
outside surface
of
C
is
+
9
Wren
switches
are
closed
charge
on
inside
t
surface
of
A
is
-i
A
When
switches
are
closed
ctrarge
on
inside
surface
ofA
and
c
are-
9
2
(a)
(b)
(c)
(d)
25.
B
l;*.i
Sz
I
I
=
fiarge on
-'-LJ
_
=
nitially
(before
a)
(b)
(c)
(o
etry
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