Advertisements
Advertisements
Question
Consider a uniform electric field in the ẑ direction. The potential is a constant ______.
- in all space.
- for any x for a given z.
- for any y for a given z.
- on the x-y plane for a given z.
Options
a, b and c
a, c and d
b, c and d
c and d
Advertisements
Solution
b, c and d
Explanation:
We know, the electric field intensity E and electric potential V are E = `- (dV)/(dr)`
Electric potential decreases in the direction of the electric field. The direction of electric field is always perpendicular to one equipotential surface maintained at the high electrostatic potential to another equipotential surface maintained at low electrostatic potential.

The electric field in the z-direction suggests that equipotential surfaces are in the x-y plane. Therefore the potential is a constant for any x for a given z, for any y for a given z and on the x-y plane for a given z.
APPEARS IN
RELATED QUESTIONS
Two charges 2 μC and −2 µC are placed at points A and B 6 cm apart.
- Identify an equipotential surface of the system.
- What is the direction of the electric field at every point on this surface?
The top of the atmosphere is at about 400 kV with respect to the surface of the earth, corresponding to an electric field that decreases with altitude. Near the surface of the earth, the field is about 100 Vm−1. Why then do we not get an electric shock as we step out of our house into the open? (Assume the house to be a steel cage so there is no field inside!)
A man fixes outside his house one evening a two metre high insulating slab carrying on its top a large aluminium sheet of area 1 m2. Will he get an electric shock if he touches the metal sheet next morning?
The discharging current in the atmosphere due to the small conductivity of air is known to be 1800 A on an average over the globe. Why then does the atmosphere not discharge itself completely in due course and become electrically neutral? In other words, what keeps the atmosphere charged?
What is the geometrical shape of equipotential surfaces due to a single isolated charge?
Draw the equipotential surfaces due to an electric dipole. Locate the points where the potential due to the dipole is zero.
Why is there no work done in moving a charge from one point to another on an equipotential surface?
Two identical point charges, q each, are kept 2m apart in the air. A third point charge Q of unknown magnitude and sign is placed on the line joining the charges such that the system remains in equilibrium. Find the position and nature of Q.
Find the amount of work done in rotating an electric dipole of dipole moment 3.2 x 10- 8Cm from its position of stable equilibrium to the position of unstable equilibrium in a uniform electric field if intensity 104 N/C.
Equipotentials at a great distance from a collection of charges whose total sum is not zero are approximately.
- The potential at all the points on an equipotential surface is same.
- Equipotential surfaces never intersect each other.
- Work done in moving a charge from one point to other on an equipotential surface is zero.
Equipotential surfaces ______.
Can two equipotential surfaces intersect each other?
Find the equation of the equipotentials for an infinite cylinder of radius r0, carrying charge of linear density λ.
Equipotential surfaces are shown in figure. Then the electric field strength will be ______.

