Structure of Matters, Electricity, Magnetism and Modern Physics 

Physics

Definition of electric charge?

Electric charge is a fundamental and characteristic of the elementary particles which are makeup of matter. These particles are proton, electron and neutron. Of these protons are positively charged, electrons are negatively charged and neutrons are neutral.

Type of electric charged  

Two types of electric charge

       I.          Positive charge

      II.          Negative charge

Property of electric charge

Property of electric charge are

       I.          Charge are additive in nature.

      II.          A charge is a conserved quantity.

    III.          Quantization of charge

What is quantization of charge

The basic cause of quantization charge is that during rubbing only an integral number of electrons can be transferred from one body to other body.  q = ne

Electric field

Electric field an electric property associated with each point in space when charge is present in any form.

E= F/Q

Point charge

All charge concentrated at a small point whose volume is negligible.

Electric flux

Electric flux, property of an electric field that may be thought as the number of electric lines of force that intersect a given area.

Capacitor

It is a type of electronic passive component or device that storage charge in the form of electric field.

Capacitance

The property of a capacitor to store electricity may be its called capacitance. The capacitance defined as the amount of charge required to raise its potential units.

 

 

 Limitations of Coulomb’s law:

Limitation of coulomb’s law are

·       Applicable only in cases when inverse law works.

·       Applicable only point charge at rest.

·       It is difficult to apply coulomb’s law when charge is arbitrary shape.

 

Application of coulomb’s law

Coulomb’s law applies only to charged objects that are not moving with respect to each other.

 

 

 

Modern physic

 

What’s relativity and type of relativity?

In physics, relativity refers to Einsten’s theory that time, space and mass are not absolute.

Two types of relativity

       I.          The general theory of relativity.

     II.          The special theory of relativity.

 

Explain the term of frame of reference with example?

The motion of the body is described with respect to some co-ordinate system, this co-ordinate system is known as frame of reference.

Two types of frames of reference

Inertial frame of reference (unaccelerated): A frame of reference, where Newton’s law holds true is called inertial frame of reference. That to be say, no external force acts on an object. It will continue at rest or in uniform motion.

Non- inertial frame of reference (accelerated): A reference frame in which a body is accelerated without being acted upon by external force is called non-inertial frame of reference.

Example:

Consider a train moving with uniform velocity. A person siting in the train drops a stone from the windrow. To this person the stone will appear to be falling vertically downward. But to a person standing near track the stone will appear to move along a parabolic path.

What is the basic postulate of special theory of relativity?

Special relativity is based on two postulates which are contradictory in classical mechanics. The two postulates of special theory of relativity are as follows

Postulate-1: All physics laws are the same in all inertial frame of reference.

Postulate-2: The speed of light in the free space has same value c=3x10^8 m/s in all inertial frame of reference. In other world the velocity of light is an invariant.

 

What is the Galilean’s transformation?

In classical mechanics those equations are related to each other with respect to two reference frames at constant speed and setup a relation between time and co-ordinate is called Galilean’s transformation.

 

What is the specification of Lorentz transformation? Or, show that for values of v<<c, Lorentz transformation reduces of the Galilean one.

If S and S’ frame of reference, the relativity velocity is very small then the velocity of light then Lorentz transformation converted into Galilean transformation.

 

What’s the condition of Lorentz transformation is converted to Galilean transformation?

When the velocity of an object is very small than to the velocity of light then Lorentz transformation is converted to Galilean transformation.

 

Define Lorentz contraction and tine dilation?

The length of a stationary object with respect to an observer in motion is shorter than the length. Measured by the observer at rest. This effect is called Lorentz contracti




Lo= Length of stationary object

V= Relativity velocity between two frames

C= speed of light

Time dilation: An interval of time observed in a moving frame of reference will be less than the same interval of time observed in a stationary frame of reference.

 

T= the interval of time measured by an observer in stationary frame of reference.

= the interval of time measured by an observer in moving frame of reference.

V= Relativity velocity between two frames.

C speed of light.