1) Explain the concept of total cost and total revenue.

A) Cost Concepts:
When an entrepreneur undertakes an act of production, he has to use various inputs like raw material, labour, capital etc. He has to make payments for such inputs. The expenditure incurred on these inputs is known as the cost of production. Cost of production increases with an increase in need of output. There are three types of costs which are as follows:

1) Total Cost (TC): Total cost is the total expenditure incurred by a firm on the factors of production required for the production of goods and services. Total cost is the sum of total fixed cost and total variable cost at various levels of output.
TC = TFC + TVC
TC = Total cost
TFC = Total Fixed Cost
TVC = Total Variable Cost
Total Fixed Cost (TFC): Total fixed costs are those expenses of production which are incurred on fixed factors such as land, machinery etc.
Total Variable Cost (TVC): Total variable costs are those expenses of production which are incurred on variable factors such as labour, raw material, power, fuel etc.

2) Average Cost (AC): Average cost refers to cost of production per unit. It is calculated by dividing total cost by total quantity of production.
AC = TC/TQ
TCTQ
AC = Average cost
TC = Total cost
TQ = Total quantity

3) Marginal cost (MC): Marginal cost is the net addition made to total cost by producing one more unit of output.
MCn = TCn – TCn-1
n = Number of units produced
MCn = Marginal cost of the nth unit
TCn = Total cost of nth unit
TCn-1 = Total cost of previous units

B) Revenue Concepts: The term ‘revenue’ refers to the receipts obtained by a firm from the sale of certain quantities of a commodity at given price in the market. The concept of revenue relates to total revenue, average revenue and marginal revenue.

1) Total Revenue (TR): Total revenue is the total sales proceeds of a firm by selling a commodity at a given price. It is the total income of a firm. Total revenue is calculated as follows:
Total revenue = Price × Quantity

2) Average Revenue (AR): Average revenue is the revenue per unit of output sold. It is obtained by dividing the total revenue by the number of units sold.
AR = TR/TQ
AR = Average Revenue
TR= Total Revenue
TQ =Total Quantity

3) Marginal Revenue: Marginal revenue is the net addition made to total revenue by selling an extra unit of the commodity.
MRn = TRn – TRn-1
MRn = Marginal revenue of nth unit
TRn = Total revenue of nth unit
TRn-1 = Total Revenue of previous units
n = Number of units sold

2) What are the determinants of supply?

Ans: – According to Paul Samuelson, “Supply refers to the relation between market prices and the number of goods that producers are willing to supply.’’
Supply refers to the quantity of a commodity that a seller is willing and able to offer for sale at a given price, during a certain period of time.
The following are the determinants supply of a commodity:

1) Price of commodity : Price is an important factor influencing the supply of a commodity. More quantities are supplied at a higher price and less quantities are supplied at a lower price. Thus, there is a direct relationship between price and quantity supplied.

2) State of technology : Technological improvements reduce the cost of production which lead to an increase in production and supply.

3) Cost of Production : If the factor price increases, the cost of production also increases, as a result, supply decreases.

4) Infrastructural facility : Infrastructure in the form of transport, communication, power, etc. influences the production process as well as supply. Shortage of these facilities decreases the supply and vice versa.

5) Government policy : Favourable Government policies may encourage supply and unfavourable government policies may discourage the supply. Government policies like taxation, subsidies, industrial policies, etc. may encourage or discourage production and supply, depending upon government policy measures.

6) Natural conditions : The supply of agricultural products depends on the natural
conditions. For example, a good monsoon and favourable climatic condition will produce a good harvest, so the supply of agricultural products will increase and unfavourable climatic conditions will lead to a decrease in supply.
7) Future expectations about price : If the prices are expected to rise in the near future, the producer may withhold the stock. This will reduce the supply and vice versa
8) Other factors : It includes, • nature of the market,  relative prices of other goods,  export and imports,  industrial relations, availability of factors of production etc. If all factors are favourable, supply of a commodity will be more and vice versa.