Electrostatic P...

A parallel plate capacitor has a capacity $$80\times 10^{-6}\ F$$ when air is present between the plates. The volume between the plates is then completely filled with a dielectric slab of dielectric constant $$20$$. The capacitor is now connected to a battery of $$30\ V$$ by wires. The dielectric slab is then removed. Then, the charge that passes now through the wire is :

Consider a parallel plate capacitator of capacity 10 $$\displaystyle \mu F$$ filled with air. When the gap between the plates is filled partly with a dielectric of dielectric constant $$4$$, as shown in figure, the new capacity of the capacitator is ($$A$$ is the area of plates):

Two identical condensers M and N are connected in series with a battery. The space between the plates of M is completely filled with a dielectric medium of dielectric constant $$8$$ and a copper plate of thickness $$\displaystyle \frac { d }{ 2 } $$ is introduced between the plates of N ($$d$$ is the distance between the plates). Then potential differences across M and N are, respectively, in the ratio:

A parallel plate capacitor with air as the dielectric has capacitance C. A slab of dielectric constant K and having the same thickness as the separation between the plates is introduced so as to fill one fourth of the capacitor as shown in the figure. The new capacitance will be :

Two metal plates each of area $$A$$ form a parallel plate capacitor with air in between the  plates. The distance between the plates is $$d$$. A metal plate of thickness $$\dfrac{d}{2}$$ and of same area $$A$$ is inserted between the plates to form two capacitors of capacitances $$C_1$$ and $$C_2$$ as shown in the figure. The effective capacitance of the two capacitors is C' and the capacitance of the capacitor initially is C, then $$\frac{C'}{C}$$ is :

The potential difference between two points A and B is $$10V$$. Point A is at higher potential. If a negative charge, q = 2 C, is moved from point A to point B, then the potential energy of this charge will:

Five capacitors, each of capacitance value $$C$$ are connected as shown in the figure. The ratio of capacitance between $$P$$ & $$R$$, and the capacitance between $$P$$ & $$Q$$, is :

In the given figure, the capacitors $${ C }_{ 1 },{ C }_{ 3 },{ C }_{ 4 },{ C }_{ 5 }$$ have a capacitance $$4 \mu F$$ each. If the capacitor $${ C }_{ 2 }$$ has a capacitance $$10 \mu F$$, then effective capacitance between $$A$$ and $$B$$ will be

A particle of mass $$10^{-3}kg$$ and charge $$5\mu C$$ is thrown at a speed $$20\ m\ s^{-1}$$ against a uniform electric field of strength $$2\times 10^{5}N\ C^{-1}$$. How much distance will it travel before coming to rest momentarily?

The V versus x plot for six identical metal plates of cross-sectional area A is as shown.The equivalent capacitance between 2 and 5 is (Adjacent plates are placed at a separation d):