If charge on a capacitor is increased by 2, C energy stored in it increases by 21% . original charge

English

Gujarati

Hindi

1. Electric Charges and Fields

normal

If the charge on a capacitor is increased by $2\, C$ the energy stored in it increases by $21\%$. The original charge on the capacitor (in coulomb) is

A

$10$

B

$20$

C

$30$

D

$40$

Solution

$\frac{\mathrm{Q}^{2}}{2 \mathrm{C}}=\mathrm{\,E}$ and $\frac{(\mathrm{Q}+2)^{2}}{2 \mathrm{C}}=1.21 \mathrm{\,E}$

$\frac{(\mathrm{Q}+2)^{2}}{\mathrm{Q}^{2}}=1.21 \Rightarrow \mathrm{Q}+2=1.1 \mathrm{Q} \Rightarrow \mathrm{Q}=20$

Standard 12

Physics

Share

Similar Questions

A wheel having mass $m$ has charges $+q $ and $-q$ on diametrically opposite points. It remains in equilibrium on a rough inclined plane in the presence of uniform vertical electric field $E =$

normal

The electric field $\vec E$ between two points is constant in both magnitude and direction. Consider a path of length d at an angle $\theta = 60^o$ with respect to field lines shown in figure. The potential difference between points $1$ and $2$ is

normal

If the distance between the plates of a capacitor having capacity $C$ and charge $Q$ is doubled then work done will be

normal

Two charges $q_1$ and $q_2$ are placed $30\,cm$ apart, as shown in the figure. A third charge $q_3$ is moved along the arc of a circle of radius $40\,cm$ from $C$ to $D$. The change in the potential energy of the $\frac{{{q_3}}}{{4\pi \,{ \in _0}}}k$ , where $k$ is

normal

Four capacitors of capacitance $10\, \mu\, F$ and a battery of $200\,V$ are arranged as shown. How much charge will flow through $AB$ after the switch $S$ is closed?

normal