Download - Physics Electrostatics MCQ[1]
-
7/26/2019 Physics Electrostatics MCQ[1]
1/8
13 - ELECTROSTATICS Page 1
(
Answers
at the
end
of
all questions
)
t ) Two point
charges
+ 8q
and
- 2q
are located
at x =0
and l t
=L respectively.
The
location
of a point on the
x
axis
at
which the
net electric field
due to these two point
charges is zero is
a )
Ll4
b )
2L
c )
4L d )
8L
2 )
Two thin wire
rings each having a radius R are
placed
at a distance
axes coinciding. The charges on the two rings are + q and - q. The
between the centres of the two rings is
a -q-
1
~ ~ : e o R
1
I b I
q q
1
I
c
I
4 ~ r e o R
3
J
A parallel plate capacitor is made by stacking . . p c e d
alternatively.
If
the capacitance between any two ~ e s is 'C',
capacitance
Is
a ) n + 1 ) C b } n - 1 } C c ) ~ C
4 ) A charged ball
B
hangs from a silk
t h r ~ h.
makes an angle
with a large conducting
sheet
P as sho in figure. The surface
charge
density o of the
sheet
is pr to
a )
cot
( b 1 cos e
( c) tan
( d I
d
their
d ) zero
I AIEEE 2005 I
plates connected
then the
resultant
I
AIEEE 2005
I
+
v
I AIEEE 2005]
6 ) B
and
C having equal radii
and
carrying
equal
charges in them
force F when kept apart
at
some
distance. A
third spherical
r
having
same radius as
that of
B
but
uncharged, is
brought
in
contact
with
B
brought in contact
with
C
and finally
removed
away from both.
The
new
force
of
. . . . . . : ~ a . r e p u lsion between B
and
C
is
a I
F
I 4 ( b I
3 F
I ( c I
F
I
8
d I
3 F
I
8
I AIEEE 2004 ]
A charged particle q is shot
towards another
charged particle Q which is fixed, with a
speed v. It
approaches
Q
upto
a
closest
distance r and then returns.
If
q was given a
speed
2v, the closest distance of
approach
would be
.
q ===-+ Q
.-r-.
a )
r
b )
2r
c )
r l 2
d )
rl
I
AIEEE 2004 ]
-
7/26/2019 Physics Electrostatics MCQ[1]
2/8
8
I
13 - ELECTROSTATICS
Answers
at the
end
of
all questions
1
Four charges equal
to
-Q are placed at the
four
corners of the
Is at its centre. If the system is In equilibrium, the value of q
is
a
} -
Q I t + 2 /2} b
I
1 + 2 /2
I I
c
I -
1 + 2 /2
I
4 4 2
Page 2
square and a charge q
I d I
9 }
Three
charges
-q1, +q2
and
-q3 are placed as
shown in the figure.
The x-component
of
the
force on -q1 is proportional
to
y
a 1 q
2
- q
3
sin 9 b } q
2
- q
3
cos 9
b2 a2 b2 a2
c 1 q
2
+
q
3
sine d 1 q
2
+
q
3
sin 9
b2 a2 b2 a2
[ AIEEE 2003 ]
10
I
A
d )
12 1
The
work done
)(
q
charge
Q
is
placed
P at a distance R /2
from
2Q
q
4ll t:,R
4,.;t:,R
I AIEEE 2003 I
respectively,
the
I AIEEE 2003 I
condenser of
capacity
I
AIEEE 2003 ]
is
introduced between the plates of a
d I remains unchanged
I AIEEE 2003 I
of
a cube, the magnitude
of
flux
through
one of Its
d ) 6q/e . [ AIEEE 2003
I
15
1
A
charged
capacitor is discharged by using a
wire
and equation
of
decreasing charge
in
wire
is
q =
0.1
elt
coulomb. The
current
in
the wire
at
t = 2 sec
will
be
a 1 0.1/e
6
b 1 0.3/e
6
c 1 0.5/e
6
d 1 0.7/e
8
[AIEEE 2002)
16
1 I f
n capacitors each of capacitance C are connected in series with a battery of V volt,
then the energy stored in all the
capacitors
will be
a } nCV
2
b } nCV
2
/4
c
I
nCV
2
/2
d
I
CV
2
/2n
[ AIEEE
2002]
-
7/26/2019 Physics Electrostatics MCQ[1]
3/8
13 - ELECTROSTATICS
Page 3
(
Answers
at the
end
of
all questions
)
t7 ) A conducting
sphere
of radius 10 em is charged with 10 ).IC. Another uncharged
sphere
of
radius
20 em is
allowed
to touch it
for
some time. I f both the
spheres
are
separated,
18
I
then surface density
of
the charges on
the
spheres will
be in
the
ratio of
a ) 1 : 4 b ) 4 : 1 e ) 1 : 2 d ) 2:1
Sixty four equal
charged
each drop is 10 volt, then
a ) 10V b ) 40V
drops are combined
to
form a
big
the potential of the
big
drop wIll be
c ) 160V d )
640V
drop.
I
ial
on
2002
19
) Three large charged sheets are having surface
charge
density
as
shown in the figure.
The
sheets
are
placed
parallel to XV plane. Then
electric field
at point P
will
be
.A
k
A
a )
4
a
k b )
4
a
k
+
-2
o
o o - - - , , - - - , - - + - - - -
z = 3a
p
z = a
c )
2 J k
o
( d
I
A
2 J k
o
z
= 0
20 ) Consider the
charge
configuration
Gaussian surface
as
shown in the figure. When flux of the
electric
field over
the
spherical surface,
due to
a
) q2
b
I
( c ) all
the
charges ( d
. (iT 2004 I
21 )
Six charges, three and three
negative, of
equal
P ~ I Q
such that the e e at 0 is double
the
electric field when
only
one
positiv e of the same
magnitude
is placed at R. U
Which
of e folio
ng arrangement
of
charges
Is possible
for
o R
P, Q, R, T d
respectively
7
a ) b +,-,+,-,+,- T ~ . J s
( c ( d } -, +,
+,
- , +, -
)l iT
2004
J
shell has
a point
charge
q kept
inside
its cavity.
Which one
of the
owing
diagrams correctly
represents the
electric
lines
of
forces ?
a
I
l iT
2003
J
-
7/26/2019 Physics Electrostatics MCQ[1]
4/8
13 - ELECTROSTATICS
Page 4
(
Answers at
the
end
of
all questions
)
23 ) Two equal
point
charges are fixed at x -a and x
+
a
on the
X-axis.
Another point
charge Q is placed at
the
origin. The change in
the
electrical potential energy of
Q
when
i t
is displaced by
a
small distance
x
along the
X-axis,
is approximately
proportional
to
I
a
I
x
I
b
I
x
2
I
c
I
x
3
I
d
I
1 I x
24 ) Two
identical
C. One
of
th
25
26 I
a)
i
I
J .
I '
: I I
/ /
: /
( q
I liT
2002
J
of
an
equilateral
c )
(d)
I
liT 2001 J
capacitor
A has a charge q
on i t
the
capacitor
B a
long time after
the
I d I
2q
[ l iT
2001 }
q
+
+ .1 - - - - - - - - - -1
+
A
s
J-
B
electric field pointing in positive X dlrection exists in
a region.
Let
A
be the
be the point on the
X-axis at x
=
1 em and C
be the point on the
Y-axis
at
em. Then the potentials at
A, B
and
C
satisfy
VA< VB
b )
VA> VB
c )
VA Vc [ l iT 2001}
Three charges Q + q and + q are placed at
the
vertices of
Q
a
right angled isosceles triangle as shown in
the
figure.
The
net electrostatic energy of
the
configuration is
zero
i f Q is
equal to
( a ) - q
1
+ J2
b ) -
2q
2
+ J2
I
c
I - 2q
d ) +
q
I
liT
2ooo
I
-
7/26/2019 Physics Electrostatics MCQ[1]
5/8
29
I
30
I
31 I
13 - ELECTROSTATICS Page 5
( Answers at the
end
of all
questions
)
A
parallel plate
capacitor of area A plate
separation
d
and capacitance
C is fitted
with three
different
dielectric constants k1, k2
and
k3 as shown in the
figure.
If a single
dielectric material is to
be used
to have
the
same capacitance
C
In
this
capacitor, then
its
dielectric constant k is given by
a
I
I b I
I
c
I
1 1 1
1
=- -
k
1
k
'
k
'
k1 k2
1
k1 + k2
k t k2
k t
k2
+
2 k 3
k t k3
+
k t k2
d ) k '
density at
A
=
charge
density at
A
:enltial at A = potential at B
A
nd
02
(
Qo b I V > Vo I c I E >
Eo
d
: uo
Two equal
negative
charges
-
q
are
fixed at
t h ~ n
, a
1
and
YaKiS.
A
positive
charge
Q Is released at s she int 2a,
0 I
charge Q
will
a 1 execute simple harmonic motion
bft
in
b 1 move to the origin
and
remain
at t
c 1 move to
in
in
ty
d 1 execute oscillatory but not
si
e
nic
motion
{liT
t985J
0,
-a
1
on the
on the Xaxls. The
[liT 1984 J
1 2 3 4 5 11 12 13 14 15 16 17 18 19 20
b d c c c b
a
d c b d d c d c
21 22 23 24 30 31 32 33 34 35 36 37 38 39
40
d c b c d d c.d b c d a.c a c c d a.c d
41
42
a
b d