ASSIGNMENT
ELECTROSTATIC POTENTIAL AND CAPACITANCE
SECTION A
1
The work done in carrying a charge Q once round a circle of radius r with charge q at the centre of the
circle is
(a) 1
4𝜋𝜀0⋅𝑄
𝑟 (b) 𝑄⋅𝑞
4𝜋𝜀0𝑟 (c) zero (d) 𝑄⋅𝑞
2𝑟
2
Three charges
qQ ,
and
q
are placed at the vertices of a right-angled isosceles triangle as shown.
The net electrostatic energy of the configuration is zero if Q is equal to
(a)
21
q
(b)
22
2
q
(c)
q2
(d)
q
3
The work done in carrying a charge of
C
5
from a point A to a point B in an electric field is 10mJ.
The potential difference
)( AB VV
is then
(a) + 2kV (b) – 2 kV
(c) + 200 V (d) – 200 V
4
There are two equipotential surface as shown in figure. The distance between them is r. The charge of
–q coulomb is taken from the surface A to B, the resultant work done will be
(a)
r
q
W
o
4
1
(b)
2
0
4
1
r
q
W
(c)
2
0
4
1
r
q
W
(d) W = zero
5
Four charges
QQQQ ,,,
are placed at the corners of a square taken in order. At the centre of the
square
(a)
0,0 VE
(b)
0,0 VE
(c)
0,0 VE
(d)
0,0 VE
6
The energy of a charged capacitor is given by the expression (
q
= charge on the conductor and C = its
+q
+q
Q
a
A
r
B
