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## Electric potential due to a dipole

If a point lies at a distance x from the midpoint of the dipole the electric potential is?

If the distance x is along the equatorial plane (a plane passing through the midpoint and perpendicular to the axis), the potential will be zero.

Please clarify what did you mean.

## Explain a method to create Uniform Electric Field.

The simplest method of creating a uniform electric field in a region is to keep two  equally charged thin plain metal sheets of opposite charge parallel to each other. As you can see from the derivation for electric field due to a plain sheet of charge, the electric field due to a plain sheet of charge is independent of distance (provided the distance is not large compared to the dimensions of the plain sheet of charge).

So, if you keep two plain metal sheets of same charge densities but opposite kind of charge, we get a fairly good uniform electric field in between the plates.

At regions close to a uniformly charged thin sheet also we get a uniform electric field, but as distance increases it may tend to become non uniform.

## What is charge basically?

It may be rather silly but still I’m really curious to know about this.  What is charge basically?  I’m tired of reading and hearing charge is an inherent property of matter,  it is that which causes electric field etc.

First of all, I would like to tell that I am interested mainly in such questions which are branded silly. But many of those silly branded questions are not so silly.

Charge is defined in intermediate Physics as below

“Electric charge is the physical property of matter that causes it to experience a force when close to other electrically charged matter. “

The concept of electric field was introduced by Faraday to explain how two charges exert force on each other without physical contact. A charged particle (and also a time varying magnetic field) produces an electric field.

## Problems from Electricity

1. The parallel plates of an air filled capacitor with area of area 1.1 x 10^8 m^2 . What must be the width of the plate be if the Capacitance is 1 Farad?
2. Four capacitor each of 2microfarad are connected in such a way that total capacitance is also 2microfarad. Show what combination gives this value. Also try to illustrate the diagram.

(Fari posted these)

1.Using the formula: $C=&space;A\varepsilon&space;/d$

and substituting , C= 1 F, A = 1.1 x 108, $\varepsilon$ = 8.8 x 10-12,

we get  , d =9.68×10-4 metres

2.

## Misconceptions on Electric Potential

We know that the potential developed at a point by a charge is the negative of the work done to bring a unit charge at that point from infinity. But how does a conducting plate develop a potential? what is the work done?

I can smell some misconceptions in your question. It is better to revise the question after revising the topic on Elelctric Potential thoroughly.

Electric potential at a point is defined as the work done per unit charge in bringing a positive test charge from infinity to that point against the electric field and without any acceleration.

When a conducting plate is charged, it is raised to some potential. Only to bring the first point charge to the plate, the work done is zero, but afterwards, repulsion is developed between the charge brought and the charge already present on the plate and therefore work is required to be done to increase the charge on the plate.

## A problem from Electrostatics

Two parallel plates A and B of infinite extent are spaced 1 cm apart. a steam of electrons is projected at a velocity corresponding to an accelerating voltage of 2kV into space betn the plates through a hole in plate A at an angle of 30 deg to it. find the value and polarity of the potential reqd betn A and B such that electrons just graze B.

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