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
The work done in carrying a charge Q once round the circle of radius r with charge Q at the centre of the circle is
zero
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 study of the effects associated with electric charges at rest is called
electromagnetism
electrostatics
magnetostatics
none of these
Two spherical conductors A and B of radii 1mm and 2mm are separated by a distance of 5 cm and are uniformly charged. If the spheres are connected by a conducting wire then the 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
Electric potential of earth is taken to be zero because earth is a good
dielectric
semiconductor
insulator
conductor
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
The electric field required to just support a water droplet of mass 10-5 g, which has a charge of 10-13 C is
107 V m-1
9.8 × 103 V m-1
106 V m-1
9.8 × 105 V m-1
Capacitance (in F) of a spherical conductor with radius 1 m is
1.1 × 10-10
10-6
9 × 10-6
10-3
The length of a given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter the change in the resistance of the wire will be
200%
100%
50%
300%
