Dielectric constant for a metal is:

A parallel plate condenser of capacity $10\mu F$ is connected to an A.C. supply voltage $e = 4\sin \left( {100\pi t} \right)$. The maximum displacement current:

Which of the following can be used as dielectric?

Which of the following is/are non-polar dielectrics?

Breakdown voltage is
$A$. voltage at which dielectric behaves as conductor
$B$. voltage at which molecules starts flowing inside the dielectric freely.
Which of the following is correct regarding above case,

Which of the following statement is false in context of dielectric?

If $C$ is the value of the capacitance of a capacitor filled with a given dielectric and $a$ is the capacitance of an identical capacitor in a vacuum, the dielectric constant, symbolized by the Greek letter kappa, , is simply expressed as

The value of the dielectric constant at room temperature (25 C, or 77 F) for air is 

Which of the following is polar dielectrics?

The insertion of a dielectric between the plates of a parallel-plate capacitor always 

The value of the static dielectric constant of any material is always 

The slight separation of charge, or polarization

Which of the following is not dielectric materials?

State whether given statement is True or False
The dielectric constant is the ability of a material to establish an electric field.

The value of relative permittivity of air is

A plane electromagnetic wave in a non magnetic dielectric medium is given by $\bar{E} = \bar{E _0} ( 4 \times 10^{-7} \times - 50 t)$ with distance being in meter and time in seconds. The dielectric constant of the medium is:

The velocity factor of a transmission line is $0.62$. Calculate dielectric constant of the insulation used

Two charges placed in air repel each other by a force of $10^{-4}N$. When  oil is introduced between the charges, the force becomes $2.5 \times 10^{-5} N$. The dielectric constant of oil is: 

The dielectric constant $k$ of a medium can be defined as $k=M/N$, where $N$ is the capacity of a parallel plate capacitor. When the space between plates is filled with air, $M$ is ?

$64$ small drops of mercury each of radius $r$ and change $q$ coalesce to from a big drop. The ratio of the surface charge density of each small drop with that of big drop is:

The force of attraction between two charges separated by certain distance in air is F1. If the space between the charges is completely filled with dielectric of constant 4 the force becomes F2. If half of the distance between the charges is filled with same dielectric the force between the charges is F3. Find F1:F2:F3 is

Water possesses a high dielectric constant, therefore

Two charges placed at a distance experience a force of x N.The force between the charges when each charge is doubled, distance between them is halved and charge placed in a medium of dielectric constant 2.52 is.

Two fixed charges separated by a distance $d$ experience a force $F$. A dielectric medium of thickness $\dfrac{d}{4}$ and dielectric constant $4$ is introduced in the space between them. Find the new force between the charges.

The relative permittivity of water is 81. If $\varepsilon _0$ and $\varepsilon$ are permittivities of vaccum and water respectively Then:

Two identical charged spheres are suspended by strings of equal lengths. The strings make an angle of ${ 30 }^{ o }$ with each other. When suspended in a liquid of density $0.8g { cm }^{ -3 }$ the angle remains the same. If density of the material of the sphere is $1.6g { cm }^{ -3 }$ the dielectric constant of the liquid is:

The capacitance of an air filled parallel plate capacitor is $8 pF$. The separation between the plates is doubled and the space between the plates is then filled with wax giving the capacitance a new value of $80 \times 10^{-12}$ farads. 
The dielectric constant of wax is

The dielectric strength of air is nearly ___ V/mm

What is the value of dielectric constant for metal ?

Surface charge density of a disc is given by $\sigma = \dfrac{\sigma _o r}{R}$ where $\sigma _0$ is a constant, $r$ is distance from the center, and $R$ is the radius of the disc. If electric potential at the centre of the disc is $\dfrac{\sigma _0 R}{\alpha \epsilon _0}$ then find value of $\alpha$.

The ratio of the forces between two small spheres with constant charges, in air and in a medium of dielectric constant $K$, is

Two conducting spheres of radii $r _1$ and $r _2$ are charged to the same surface charge density. The ratio of electric fields near their surface is -

Two identical balls each having mass density $ \rho $ mass m and charge q are suspended from a common point by two insulating mass less string of equal length .At equilibrium each string makes an angle $ \theta $ with the vertical Now both the balls are immersed in a liquid.At equilibrium $ \theta $ remains same If the mass density of liquid is $ \sigma $ then dielectric constant of liquid will be

Force $'F'$ exists between two point charges in air, if a medium having $\epsilon _{R} = 6$ is inserted between charges, the new force between them.

Two identical balls each having mass density $ \rho _1 $ mass m and charge q are suspended from a common point by two insulating massless strings of angle $\theta$ with the vertical. Now both the ball are immersed in a liquid.At equilibrium, $ \theta $ remain same. If the mass density of liquid is $ \sigma  $ then dielectric constant of liquid will be

Two charges when kept at a distance of $1 m$ apart in vacuum have some force of repulsion. If the force of repulsion between these two charges be same, when placed in an oil of dielectric constant $4$, the distance of separation is 

The induced charge on the dielectric of a capacitor of capacitance $4\mu F$ when charged by a battery of $50$V, is (dielectric constant of the dielectric $=4$):

When a metal plate is introduced between the two plates of a charged capacitor and insulated from them, then

A charge is placed at some distance from a non uniform conductor . Now charge is slowly moved towards the conductor at a slow rate ,now which of the following is correct regarding it,

On the application of electric field on a dielectric and a conductor one by one which of the following is observed

Which of the following statement is correct regarding dielectric?

Which of the material can be used as a dielectric?

Dielectric constant, property of an electrical insulating material (a dielectric) equal to

Which of the following can be used as dielectric?

 The capacitance of a capacitor

The voltage can be increased, but electric breakdown will occur if the electric field inside the capacitor becomes too large. The capacity can be increased by 

A dielectric slab of thickness $6 cm$ is placed between the plates of a parallel plate capacitor. If the distance between plates is reduced by $4 cm$, the capacity of the capacitor remains the same. Find the dielectric constant of the medium.

A parallel plate condenser is charged to $100$ volt. In this context which one of the following statements is true?

At room temperature, if the relative permittivity of water be $80$ and the relative permeability be $0.0222$, then the velocity of light in water is ________ $m/{s}^{-1}$

Surface charge density of a thin disc having radius $R$ varies with distance from centre as $\sigma =\sigma _{0}\dfrac {R}{r}(r\neq 0) $ then total charge of disc is