The inductance of the oscillatory circuit of a radio station is 10 milli henry band its capacitance is $0.25 \mu F$. Taking the effect of the resistance negligible, wavelength of the broadcasted waves will be (velocity of light = $3.0  \ 10 ^4 \ m/s, \pi = 3.14$):

The capacitance of an air filled parallel plate capacitor is $10\times {10}^{-12}F$. 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 $40\times {10}^{-12}F$. The dielectric constant of wax is:

Each plate of parallel plate capacitor has a charge q on it. The capacitor is now connected to a battery. Now,

We assume that earth is at zero potential because capacitance of the earth is

1000 drops ofwater each of radius r and charged to a potential V coalesce together to form a big drop. The potential of big drop will be

A circuit contains a capacitor and inductance each with negligible resistance. The capacitor is initially charged and the charging battery is disconnected. At subsequent time, the charge on the capacitor will 

A fully charged capacitor has a capacitance C.It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity s and mass m. If the temperature of the block is raised by $\Delta T$, the potential difference V across the capacitance is:

Capacitance of an isolated metallic sphere having radius $8.1$ mm is nearly :

Two points A and B lying on Y- axis at distances 12.3 cm and 12.5 cm from the origin. The potentials at these points are 56V and 54.8V respectively, then the component of force on a charge of $4\mu C$ placed at A along Y- axis will be

The capacitance of an isolated conducting sphere of radius $R$ is proportional to

Two metal spheres of capacitance, ${C} _{1}$ and ${C} _{2}$ carry some charges. They are put in contact and then separated. The final charges ${Q} _{1}$ and ${Q} _{2}$ on them will satisfy:

A $110V. 60W$ lamp is run from a $220V$ AC mains using a capacitor in series with the lamp, instead of a resistor then the voltage across the capacitor is about:

Three capacitors of capacitances 6 µF each are available. The minimum and maximum capacitances, which may be obtained are

The capacitance of a spherical condenser is $1mF$. If the spacing between the two spheres is $1mm$, then the radius of the outer sphere is

The capacitance of a spherical condenser is $1mF$. If the spacing between the two spheres is $1mm$, then the radius of the outer space is

A capacitor has capacitance $2F$. plate separation $0.5 cm $ then area of plate  [You will realize from your answer why ordinary capacitors are in the range of μF or less. However, electrolytic capacitors do have a much larger capacitance $(0.1 F)$ because of very minute separation between the conductors.]:

A coil, a capacitor and an A. C. source of rms voltage 24 V are connected in series. By varying the frequency of the source, a maximum rms current of 6 A is observed. If the coil is connected to a battery of emf 12 V and internal resistance $4\Omega$, the current through it will be    

The capacitance (C) for an isolated conducting sphere of radius(a) is given by $4\pi \varepsilon _0a$. If the sphere is enclosed with an earthed concentric sphere, the ratio of the radii of the spheres being $\dfrac{n}{(n-1)}$ then the capacitance of such a sphere will be increased by a factor?

If the circumferences of a sphere is $2\ m$, then capacitance of sphere in water would be:

If 'Q' is the quantity of charge, 'V' the potential and 'C' the capacity of a conductor, they are related as:

Inside a hollow charged spherical conductor, the electric field is found to be.

Of the following about capacitive reactance which is correct