(d) The change in energy stored is1 1 (^21)
2
CV
K
Two thin dielectric slabs of dielectric constants K 1
and K 2 (K K 1 2 ) are inserted between plates of
a parallel plate capacitor, as shown in the figure.
The variation of electric field E between the plates
with distance x as measured from P is correctly
shown by
(a) (b)
(c) (d)
A parallel plate condenser has a uniform electric
field E (V/m) in the space between the plates. If the
distance between the plates is d(m) and area of
each plate is A(m^2 ), the energy (joule) stored in
the condenser is
(a) E Ad^2 / 0 (b) 0 2
1
2
E
(c)
2
0
1
2
E Ad (d) 0 EAd
A series combination of n 1 capacitors, each of
value C 1 , is charged by a source of potential
difference 4V. When another parallel combination
of n 2 capacitors, each of value C 2 , is charged by
a source of potential difference V, it has the same
(total) energy stored in it, as the first combination
has. The value of C 2 , in terms of C 1 , is then
(a)
2
1
1
2
n
C
n (b)
2
1
1
16
n
C
n (c)
1
1 2
2 C
nn (d)
1
1 2
16 C
nn
Three capacitors each of capacitance C and of break
down voltage V are joined in series. The
capacitance and breakdown voltage of the
combination will be
(a) 3C, 3V (b) 3 ,
3
V
C (c) ,3
3
C
V (d) ,
3 3
C V
5.
[2014]
6.
[2011]1]
7.
[2010]
8.
[2009]
a d Delete a c
c d c
(^12)
2
U CVi
After connecting the two capacitors the common
potential is given by
1 1 2 2
1 2
0
f 2
CV CV CV C V
V
C C C C
2
1 1
2
f 2 2 2 i
V
U C U
Energy decreases by a factor of 2
Initial energy stored in 2
- Sol:
2.Sol: F capacitor (^122)
2
i 2
U V V
Final voltage after switch 2 is ON
1 1 2 2
1 2
2
0.2
f 10
CV CV V
V V
C C
Final energy in both the capacitors
2
2
1 2
1 2 1 2
10 0.2
f 2 f 2 10
V
U C C V V
So energy dissipated
2 2
2
0.2
100 80%
V V
V