A parallel plate capacitor having capacitance 12 , pF is charged … - Vidyadip

Question

A parallel plate capacitor having capacitance $12\, pF$ is charged by a battery to a potential difference of $10\, V$ between its plates. The charging battery is now disconnected and a porcelain slab of dielectric constant $6.5$ is slipped between the plates. The work done by the capacitor on the slab is.......$pJ$

✓

Answer

b
$W = \frac{{{Q^2}}}{{2c}} - \frac{{{Q^2}}}{{2ck}}$

$ = \frac{{{Q^2}}}{{2c}}\left[ {1 - \frac{1}{k}} \right]$

$ = \frac{1}{2} \times 12 \times 100\,pJ\left( {1 - \frac{1}{{6.5}}} \right)$

$ = \frac{{12 \times 100 \times 11}}{{2 \times 13}}\,{\text{pJ}}$

$ = 507.69\,{\text{pJ}}$

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

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

Similar questions

A bullet of mass $10 \;g$ leaves a rifle at an initial velocity of $1000 \;m/s$ and strikes the earth at the same level with a velocity of $500\; m / s$. The work done ($Joule$) in joule overcoming the resistance of air will be

The net current flowing in the given circuit is _________ A.

→

A body of mass ${m_1}$ moving with a velocity$ 3 ms^{-1}$ collides with another body at rest of mass ${m_2}.$After collision the velocities of the two bodies are $2 ms^{-1} \,and \, 5ms^{-1}$ respectively along the direction of motion of ${m_1}$ The ratio $ \frac{m_1}{m_2}= $

An electric appliance supplies $6000\, {J} / {min}$ heat to the system. If the system delivers a power of $90\, {W}$. How long (in $sec$) it would take to increase the internal energy by $2.5 \times 10^{3}\, {J}$ ?

A point moves in $x -y$ plane according to the law $x = 3\, cos\,4t$ and $y = 3\, (1 -sin\,4t)$. The distance travelled by the particle in $2\, sec$ is...........$m$ (where $x$ and $y$ are in $metres$ )

A Carnot's engine used first an ideal monoatomic gas then an ideal diatomic gas. If the source and sink temperature are ${411^o}C$ and ${69^o}C$ respectively and the engine extracts $1000\, J $ of heat in each cycle, then area enclosed by the $PV$ diagram is ........ $J$

$50$ tuning forks are arranged in increasing order of their frequencies such that each gives $4 \,beats/sec$ with its previous tuning fork. If the frequency of the last fork is octave of the first, then the frequency of the first tuning fork is ... $Hz$

A ball will a speed of $9\, m / s$ collides with another identical ball at rest. After the collision, the direction of each ball makes an angle of $30^{\circ}$ with the original direction. The ratio of velocities of the balls after collision is $x : y$ where $x$ is........

A lamp is hanging at a height of $4\,m$ above a table. The lamp is lowered by $1\,m$. The percentage increase in illuminace will be.....$\%$

The figure shows a network of five resistances and two batteries The total electrical power consumed by the circuit is ............... $W$