Showing posts with label Broad Questions. Show all posts
Showing posts with label Broad Questions. Show all posts

## E-commerce:

E-commerce or Electronic Commerce is a modern way of business. Transaction in case of buying or selling a product or service through electronic devices and internet connection is E-commerce. In E-commerce, the buyer and seller can not only communicate with each other but also the buyer can pay and the seller can receive payments through internet connection which can be called electronic payment service.

Here is a list of 12 Advantages of E-commerce.

## E-commerce:

E-commerce or Electronic Commerce is a modern way of business. Transaction in case of buying or selling a product or service through electronic devices and internet connection is E-commerce. In E-commerce, the buyer and seller can not only communicate with each other but also the buyer can pay and the seller can receive payments through internet connection which can be called electronic payment service. So in E-commerce, a product travels to buyer from seller or a service is served to it's buyer without the need for the buyer to meet the seller by appearing physically. Again, in E-commerce, the seller receives payment for his/her sale without meeting the buyer physically.

## Value of Half-Life Period

From the law of radioactive disintegration, we know,

## The Law of Radioactivity Disintegration:

Let, N be the number of atoms present in the radio element at a given instant t. Then the rate of decrease,

Here, λ is the disintegration constant. It is defined as the ratio of the amount of the substance which disintegrates in a unit time to the amount of substance present.

## General Properties of Nucleus:

### (i) Nuclear Size:

From Rutherford’s work, the mean radius of nucleus is  and the radius of the atom is . Thus the radius of the nucleus is 10,000 times smaller than the radius of the atom.

The empirical formula for the nuclear radius is,

Here, A is the mass number,  is a constant.

From this formula the radius of the Carbon () nucleus is.

## The Required de Broglie Wavelength:

A photon of light of frequency  has the momentum,

But, . Therefore, the momentum of the photon can be expressed in terms of wavelength λ as,

The wavelength of a photon is, therefore, specified by its momentum according to the relation,

## Einstein’s Photoelectric Equation :

According to Einstein, light of frequency  consists of a shower of photons, is of energy . When a photon of light of frequency  is incident on a metal, a part of the energy acquired by the electron is used to pull out the electron from the surface of the metal and the rest of it is utilized in imparting K.E. to the emitted electron.