EXERCISE 4

A parallel plate capacitor with air as dielectric is charged by a $dc$ source to a potential $V,$ without disconnecting the capacitor from the source, air is replaced by another dielectric medium of dielectric constant $K.$ State with reasons how does the electric field between the plates changes.

A parallel plate capacitor with air as dielectric is charged by a $dc$ source to a potential $V,$ without disconnecting the capacitor from the source, air is replaced by another dielectric medium of dielectric constant $K.$ State with reasons how does energy stored in the capacitor changed.

A parallel plate air capacitor has capacitance $C.$ What will be the capacitance of the capacitor if it is half-immersed in an oil of dielectric constant $1.6$ with the plates remaining perpendicular to the surface of the oil.

Two dielectric slabs of dielectric constants $K_1$ and $K_2$ are filled in between the two plates, each of area $A,$ of the parallel plate capacitor as shown in figure, Fig. 4.76 Find the net capacitance of the capacitor.

Find the equivalent capacitance between the points $A$ and $B$ of the given combination of capacitors, Fig. 4.77. If a battery

of $\mathrm{emf}10 \mathrm{V}$ is connected between the points $A$ and $B$, calculate the total charge in the circuit.

Find the equivalent capacitance of the combination of capacitors between the points $A$ and $B$ as shown in the figure, Fig. 4.78 . Also calculate the charge that flows in the circuit when a $100 \mathrm{V}$ battery is connected between the points $A$ and $B$

Four capacitors are connected as shown in the Fig 4.79 calculate the equivalent capacitance between the points $X$ and $Y$

A Van-de-Graaff generator has metallic sphere of diameter $1 \mathrm{m}.$ How much charge in coulomb is required to raise its potential to $2.7\times {10}^6$ volts ?