A 2,μ F capacitor is charged to a potential =10 V . Another 4,μ F cap

English

Gujarati

Hindi

1. Electric Charges and Fields

normal

A $2\,\mu F$ capacitor is charged to a potential $=10\ V$ . Another $4\,\mu F$ capacitor is charged to a potential $= 20\ V$ . The two capacitors are then connected in a single loop, with the positive plate of one connected with negative plate of the other. What heat is evolved in the circuit ?.........$\mu J$

A

$300$

B

$600$

C

$900$

D

$450$

Solution

Given : $C_1=2 \mu F ; C_2=4 \mu F ; V_1=10 V ; V_2=20 V$

Solution: As we know that,

By energy Conservation

$\frac{1}{2} c _1 v ^2+\frac{1}{2} c _2 v _2^2=\frac{1}{2} c _1 v ^2+\frac{1}{2} c _2 v ^2+ H$

$\frac{1}{2} 2(10)^2+\frac{1}{2} 4(20)^2=\frac{1}{2}(2+4)(10)^2+ H$

$100+800=300+ H$

$H =900-300$

$=600 \mu J$

Standard 12

Physics

Share

Similar Questions

An electric point charge $10^{-3}\,\mu C$ is placed at the origin $(0, 0)$ of $X-Y$ co- ordinate system. Two points $A$ and $B$ are situated at $(\sqrt 2, \sqrt 2)$ and $(2, 0)$ respectively. The potential difference between the points $A$ and $B$ will be…..$volt$

normal

Electric charges $q, q, -2\,q$ are placed at the comers of an equilateral triangle $ABC$ of side $l$. The magnitude of electric dipole moment of the system is

normal

A parallel plate capacitor with air between the plates has a capacitance of $9\, pF$. The separation between its plates is $'d'$. The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant $K_1=3$ and thickness $\frac{d}{3}$ while the other one has dielectric constant $K_2 = 6$ and thickness $\frac{2d}{3}$. Capacitance of the capacitor is now….$pF$

normal

A capacitor is charged by using a battery which is then disconnected. A dielectric slab is then slipped between the plates, which results in

normal

Five point charges each having magnitude $'q'$ are placed at the corners of regular hexagon as shown in figure. Net electric field at the centre $'O'$ is $\vec E$ . To get net electric field at $'O'$ to be $6\vec E$ , charge placed on the remaining sixth corner should be

normal