Download App

STD 12 - 2. Electric potential and capacitance — NEET STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceNEETSTD 12 - 2. Electric potential and capacitance4 Marks
Question
Two identical parallel plate capacitors of capacitance $C$ each are connected in series with a battery of emf, $E$ as shown below. If one of the capacitors is now filled with a dielectric of dielectric constant $k$, then the amount of charge which will flow through the battery is (neglect internal resistance of the battery)
✓

Answer

(b)

Initially, $\quad C_{ eq }=\frac{C}{2}, V=E$

So, charge that is delivered by cell is

$Q_1=C_{ eq } E=\frac{C E}{2}$

In series charge remains same for both capacitors.

When one of capacitors is filled with a dielectric then,

$C_{ eq }=\frac{k C^2}{(C+k C)}=\left(\frac{k}{1+k}\right) C$

As battery remains connected, $V=E$. So, charge of combination

$Q_2=C_{ eq } V=\left(\frac{k}{1+k}\right) C E$

So, extra charge given by cell after insertion of dielectric is

$\Delta Q=Q_2-Q_1=\left(\frac{k}{1+k}-\frac{1}{2}\right) C E$

$=\frac{k-1}{2(k+1)} \cdot C E$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

A soap bubble is given a negative charge, then its radius
→
Magnetic field at the centre $O$ due to the given structure is
→
Two rectangular blocks $A$ and $B$ of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of $A$ is $100°C$ and that of $B$ at the other end is $0°C$ . If the ratio of their thermal conductivity is $1 : 3$ , then under steady state, the temperature of the junction in contact will be ........ $^oC$
→
A point charge $q$ is held at the centre of a circle of radius $r . B, C$ are two points on the circumference of the circle and $A$ is a point outside the circle. If $W_{A B}$ represents work done by electric field in taking a charge $q_0$ from $A$ to $B$ and $W_{A C}$ represents the workdone from $A$ to $C$, then
→
Donor type impurity is found in
→
In a transformer, number of turns in the primary are $140$ and that in the secondary are $280$. If current in primary is $4\,A$, then that in the secondary is......$A$
→
The electric field in an electromagnetic wave is given by $E =56.5 \sin \omega( t - x / c ) \;NC ^{-1}$. Find the intensity of the wave if it is propagating along $x-$axis in the free space. (Given $\left.\varepsilon_{0}=8.85 \times 10^{-12} \;C ^{2} N ^{-1} m ^{-2}\right)$
→
Electric field in a plane electromagnetic wave is given by ${E}=50 \sin \left(500 {x}-10 \times 10^{10} {t}\right) \,{V} / {m}$ The velocity of electromagnetic wave in this medium is :

(Given ${C}=$ speed of light in vacuum)

→
In a double -slit experiment, green light $\left( {5303\,\mathop A\limits^o } \right)$ falls on a double slit having a separation of $19.44\,\mu m$ and a width of $4.05\,\mu m$. The number of bright fringes between the first and the second diffraction minima is
→
When ultraviolet rays are incident on metal plate, then photoelectric effect does not occurs. It occurs by the incidence of
→