A point Q lies on the perpendicular bisector of an electric dipole of dipole moment p. If the distance of Q from the dipole is r, (much larger than the size of the dipole) then electric field at Q is proportional to
p-1 and r2
p and r-2
p2 and r-3
p and r-3
Intensity of an electric field (E) depends on distance r due to a dipole, is related as
E α 1/r
E α 1/r2
E α 1/r3
E α 1/r4
The formation of a dipole is due to two equal and dissimilar point charges placed at a
short distance
long distance
above each other
none of the above
Two spherical conductors A and B of radii 1 mm and 2 mm are separated by a distance of 5 cm and are uniformly charged. If the spheres are connected by a conducting wire then in equilibrium condition, the ratio of the magnitude of the electric fields at the surfaces of spheres A and B is
4 : 1
1 : 2
2 : 1
1 : 4
Two concentric spheres of radii R and r have similar charges with equal surface densities (σ). What is the electric potential at their common centre?
none of these
A point charge + q is placed at midpoint of a cube of side L. The electric flux emerging from the cube is
zero
The study of the effects associated with electric charges at rest is called
electromagnetism
electrostatics
magnetostatics
An electric dipole, consisting of two opposite charges of 2 x 10-6 C each separated by a distance 3 cm is placed in an electric field of 2 x 105N/C. Torque on the dipole is
12 x 10-1 Nm
12 x 10-2 Nm
12 x 10-3 Nm
12 x 10-4 Nm
The potential of a point A is -500 V and that of another point B is +500 V. The work done by an external agent to take 2 units of negative charge from B to A is
+1000 J
-1000 J
+2000 J
-2000 J
The electric potential V at any point (x1, y1, z1) in space is given by V = 4x2 volt. The electric field at (1, 0, 2) m in Vm-1 is
8, along negative x-axis
8, along positive x-axis
16, along negative x-axis
16, along positive y-axis
