Law of supply with its assumption

LAW OF SUPPLY WITH ITS ASSUMPTION

This law was formulated by ' Alfred Marshall.' He has explained this law in the book ' principles of economics' published in the year 1890. In this law he has explained the functional relationship between price and quantity supplied.
Meaning of supply:
Supply refers to the quantity of a commodity offered for sale at a different alternative prices at a point of time or during a period of time.
Supply function:
It is a symbolic expression of law of supply. It states that quantity supplied is the function of price.
                              QS=f( p)
Where,
           QS= Quantity supplied
            F= function of
            P= price
Statement of the law:
 Alfred Marshall stated the law as" other think remaining the same there is a direct relationship between price and quantity supplied. "
Supply schedule:
It refers to " a list or table showing various quantity of a commodity offered for sale or supply at different alternative price at a point of time or during a period of time. "

In the above table when the price is one rupee quantity supplied is 10 units. When price rises to Rs. 2 quantity supplied also rises to 20 units. As price keeps on rising like RS. 3 Rs. 4, etc. Quantity supplied also keeps on rising like 30 units, 40 units and so on. It means supply is directly related to price.
Supply curve:
It is a diagrammatic representation of supply schedule. The following supply curve is drawn with the help of schedule given above.

In the o diagram we have represented price on  Y - axis. When we represented the figures given in the supply schedule we got the points a,b,c,d,&e on the diagram. The locus of all these points constitute supply curve (ss). The supply curve slopes upwards from left to right. Because of the direct relationship between price and quantity supplied the supply curve has positive slope or upward slope.
ASSUMPTION
1) Cost of production:
As the producers produces more and more, the a average cost of production is assumed to be the same.
2) period of production:
It takes the same period of time to produce the given commodity.
3) State of technology
There is no change in the method of production or state of technology.
4) Scale of production
There is no change in the scale of production.
5) Self consumption :
The producers keeps the same proportion of production for his consumption.
6) Development of transport and communication:
There is no change in the development of transport & communication systems.
7) Development of banking and finance:
There is no change in the development of banking and financial system
8) Natural factors:
There is no natural calamities occurred and the a availability of raw material etc. are assumed to be the same.
9) Need for cash:
The seller is not urgently in need of cash.
10) Expectation regarding future change in price :
It is assumed that the sellers do not expect the future change in price.