The bob of a simple pendulum has mass 2 g and charge of . It is at rest in a uniform horizontal electric field of intensity . At equilibrium, the angle that the pendulum makes with the vertical is :
(take )
Determine the charge on the capacitor in the following circuit :
Seven capacitors , each of capacitance 2 , are to be connected in a configuration to obtain an effective capacitance of . Which of the combinations, shown in figures below, will achieve the desired value ?
The given graph shows variation (with distance r from centre) of:
potential of a uniformly charged spherical shell
Electric field of a uniformly spherical shell
Electric field of a uniformly charged sphere
Potential of a uniformly charged sphere
An electric field of 1000 V/m is applied to an electric dipole at angle of 45^{o} . The value of electric dipole moment is 10^{-29} C.m. What is the potential energy of the electric dipole ?
- 20 x 10^{-18 }J
- 10 x 10^{-29 }J
- 7 x 10^{-27 }J
- 9 x 10^{-20 }J
In the figure shown below the charge on the left plate of the 10 capacitor is - 30. The charge on the right plate of the 6 capacitor is:
Three charges Q, +q and +q are placed at vertices of a right - angle isosceles triangle as shown blow. The net electrostatic energy of the configuration is zero, if the value of Q is:
+q
-2q
A parallel plate capacitor with plates of area 1m^{2} each, are at a separation of 0.1 m. If the electric field between the plates is 100 N/C , the magnitude of charge on each plate is :
(Take )
9.85 X 10^{-10} C
8.85 X 10^{-10} C
7.85 X 10^{-10} C
6.85 X 10^{-10} C
A paraller plate capacitor having capacity 12 pF is charged by a battery to a potential difference of 10 V between its plates. The charging battery is now disconnected and a poecelain slab of dielectric constant 6.5 is slipped between the plates. The work done by the capacitor on the slab is :
In the circuit shown, find C if the effective capacitance of the whole circuit is to be 0.5 . All values in the circuit are in .
Charge -q and +Q located at A and B, respectively, constitute an electric dipole.Distance AB=2a, O is the mid point of the dipole and OP is perpendicular to AB. A charge Q is places at P where OP=y and y>>2a. The charge Q experience an electrostatic force F. If Q is now moved along the equational line to P' such that the force on Q woll be close to :
9F
27 F
F/3
3F
Four equal point charges Q each are placed in the xy plane at (0,2), (4,2), (4, -2) and (0, -2). The work required to put a fifth charge Q at the ogigin of the coordinate system will be :
A charge Q is distributed over three concentric spherical shells of radii a,b,c (a<b<c) such that their surface charge densities are equal to one another. The total potential at a point at distance r from their common centre, where would be:
A Parallel plate capacitor is of area and separation 3mm. The gap is filled with three dielectric materials of equal thickness (see figure) with dielectric constants and . The dielectric constant of a material which when fully inserted in above capacitor, gives same capacitance would
be:
Two electric dipoles, A, B with respective dipole moments are placed on the x-axis with a separation R, as shown in the figure
The distance from A at which both of them production the same potentials is:
There is a uniform spherically symmetric surface charge density at a distance R_{o} from the origin. The charge distribution is initially at rest and starts expanding because of mutual repulsion. The figure that represents best the speed V(R(t)) of the distribution as a function of its instantaneous radius R(t) is :
In the figure shown, after the switch 'S' is turned from position 'A' to posittion 'B' , the energy dissipated in the circuit in terms of capacitance 'c' and total charge 'Q' is :
A parallel plate capacitor with square plates is filled with four dielectrics constant K_{1} , K_{2}, K_{3} , K_{4} arranged as shown in the figure. The effective dielectric constant K will be:
Charge is distributed within a sphere of radius R with a volume charge density , where A and a are constants. If Q is the total charge of this charge distribution, the radius R is:
Determiine the electric dipole moment of the sysytem of three charges, placed on the vertices of an equilateral triangle, as shown in the figure :