Normative economic analysis deals with 'What ought to be' phenomenon. It indicates what is good or what is bad.

(i) False When there is underutilisation or inefficient utilisation of resources, the economy will produce at a point inside the Production Possibility Curve.
(ii) False Massive unemployment does not cause a shift in the Production Possibility Curve but causes the economy to operate at a point inside the Production Possibility Curve.
(iii) True A Production Possibility Curve is drawn by assuming given resources and technology constant.  With these assumptions, the economy can operate at a point on Production Possibility Curve but not beyond it.

Opportunity cost for a commodity is the amount of other commodity that has been foregone in order to produce the first. For example, if a person 'A' is working in a bank and gets a job offer of a journalist.  A as a bank executive, gets Rs. 40000 and as journalist would get Rs. 45000.  In this case, the opportunity cost of being a journalist is Rs. 40000, which is the second best opportunity.

Opportunity cost is the value of a factor in its next best alternative use.  In other words, the opportunity cost of any commodity is the amount of other good which has been given up in order to produce that commodity.
Production Possibility Schedule

Marginal Opportunity Cost  \(={\triangle\ Loss\ of\ Output\over \triangle\ Gain\ of\ Output}\)

Economics is concerned with the study of economic problems at the level of an economy as a whole, on one side and on the other, it is concerned with the study of an individual too. The subject matter of economics is studied under two broad branches viz microeconomics and macroeconomics.
Vital theories or studies of microeconomics are:
(i) Theory of consumer behaviour.
(ii) Theory of price.
(iii) Theory of producer behaviour.
Vital theories or studies of macroeconomics are:
(i)Theory related to equilibrium level of output and employment.
(ii) Theory related to inflationary and deflationary gap in the economy.
(iii) Theory of multiplier.
(iv) Study of government budget.
(v) Study of exchange rate and Balance of Payments (BoP).

Examples of microvariables are:-
(i) Consumer's demand
(ii) Market price of a commodity
(iii) Firm's output (supply)
Examples of macrovariables are:
(i) Aggregate Demand in the economy.
(ii) General price level in the economy.
(iii) Aggregate Supply in the economy.

All of these

Consumer preference

Four major sectors in an economy, according to the macroeconomic point of view are:
(i) Firms: These are the production units which hire inputs like land, labour, capital and enterprise and undertake the task of production.
(ii) Households: They are the suppliers or owners of factor services to the firms,
like land, labour, capital and enterprises. In return for these, households receive factor incomes like Rent, Wages, Interest and Profit from the firms.They spend these incomes on buying various goods and services to satisfy their wants, i.e., incur 'Consumption Expenditure'.
(iii) Government: It imposes taxes and spends money on building social
infrastructure like roads, schools, providing health services, etc. It frames laws and enforces them and delivers justice to the people.
(iv) External sector (R.O.W. Sector): In almost all countries of the world, external trade, in the form of imports and exports of goods, services and capital, takes place.

Yes, a production possibility curve can be a straight line if marginal rate of transformation is constant. MRT is constant if all the resources are equally efficient in production of all goods. But, this is not a common situation because resources are actually not equally efficient in the production of all goods. So, PPC'is generally concave

Cleanliness leads to a reduction in the chances of people falling sick. Thus, it can ensure better health. When one is healthy, he will be regular in his work. This will raise the productive efficiency of the people. Ultimately, the country's production potential will get a boost. This rise in the country's potential to produce will shift the Production Possibility Curve to the right.

An economic problem mainly arises on account of the scarcity of the resources available to satisfy the unlimited human wants. To a large extent, if the resources were not limited, the economic problem would not have arisen, because every want could be satisfied, i.e., everyone could have everything. But this indeed is not true as the reality is that relative scarcity will continue to prevail and the other related problem -of 'choice' would always exist. One is always confronted with the problem of what to choose and what to give up, i.e., sacrifice. Thus, scarcity, being a relative term, will always exist and so would an economic problem.