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
MCQ
A capacitor of capacitance $C$  is initially charged to a potential difference of $V$ $volt$. Now it is connected to a battery of $2V$ with opposite polarity. The ratio of heat generated to the final energy stored in the capacitor will be
  • A
    $1.75$
  • ✓
    $2.25$
  • C
    $2.5$
  • D
    $0.5$
✓

Answer

Correct option: B.
$2.25$
b
Here $q_{i}=C V$ and $q_{f}=2 C V$

As battery is connected with opposite polarity so charge flow through the battery is

$\Delta q=q_{f}-\left(-q_{i}\right)=2 C V+C V=3 C V$

Initial energy stored $, U_{i}=\frac{1}{2} C V^{2}$ and

Final energy stored $, U_{f}=\frac{1}{2} C(2 V)^{2}=2 C V^{2}$

Generated heat, $H=\left(U_{f}-U_{i}\right)-\Delta q(2 V)=2 C V^{2}-\frac{1}{2} C V^{2}-6 C V^{2}=-\frac{9}{2} C V^{2}$

Thus, $\frac{H}{U_{f}}=\frac{9 C V^{2}}{2\left(2 C V^{2}\right)}=2.25$

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

The angle between two vectors $ - 2\hat i + 3\hat j + \hat k$ and $\hat i + 2\hat j - 4\hat k$ is ....... $^o$
→
Initially the switch $S$ is open and energy stored in inductance $L$ connected in series with battery is $E$ , Now switch $S$ is closed. The energy stored in both the inductors after long time is
→
Assertion: The specific charge of positive rays is not constant.
Reason: The mass of ions varies with speed.
→
Two projectiles are projected at $30^{\circ}$ and $60^{\circ}$ with the horizontal with the same speed. The ratio of the maximum height attained by the two projectiles respectively is:
→
In figure shown, both blocks are released from rest. Find the time to cross each other ? ......... $\sec$
→
The length of a magnet is large compared to it's width and breadth. The time period of its oscillation in a vibration magnetometer is $T$. The magnet is cut along it’s length into six parts and these parts are then placed together as shown in the figure. The time period of this combination will be
→
Consider the ray diagram for the refraction given below. The maximum value of angle $\theta$ for which the light suffers total internal reflection at the vertical surface, is
→
A body of $5 \,kg$ weight kept on a rough inclined plane of angle $30^{\circ}$ starts sliding with a constant velocity. Then the coefficient of friction is (assume $g=10 \,ms ^{-2}$ )
→
The mass of a particle is $1\,\,kg$ and it is moving along  $x-$ axis. The period of its small oscillation is $\frac {\pi }{2}$ . Its potential energy may be
→
A vector in $x-y$ plane makes an angle of $30^{\circ}$ with $y$-axis The magnitude of $y$-component of vector is $2 \sqrt{3}$. The magnitude of $x$-component of the vector will be
→