CBSE Class 11 Economics Question Paper Set 18 with Solutions

Answer: An enumerator is the person who collects information from the respondents (by visiting them and filling in the questionnaire/schedule) during a survey.

Teacher's Note:
1. An enumerator only collects the data; the investigator plans and directs the survey.
2. Do not confuse enumerator with respondent, who is the person giving the information.

Answer: Head note (prefatory note). It is placed just below the title and states the units of measurement or other explanation about the table.

Teacher's Note:
1. Remember the parts of a table in order: number, title, head note, stub, caption, body, footnote, source note.
2. Do not confuse head note with footnote, which comes at the bottom and explains a particular item.

Answer: The highest frequency is 9, which belongs to the marks 45.
Mode = 45 marks

Teacher's Note:
1. In a discrete series, the mode is simply the value with the highest frequency.
2. Do not give the frequency (9) as the answer; the mode is the value (45).

Answer: (b) Median. The point where the less than and more than ogives cross has the median as its x-coordinate.

Teacher's Note:
1. Ogives are cumulative frequency curves, and the median divides the cumulative frequency into two equal halves.
2. Mode is found from a histogram, not from ogives.

Answer: A source note is a statement placed at the bottom of a table that tells from where the data in the table have been taken (the source of the data).

Teacher's Note:
1. It lets the reader check the reliability of the data.
2. Source note comes at the very end, after the footnote.

Answer: (b) Pie diagram. It shows how a total is divided into its component parts, as sectors of a circle.

Teacher's Note:
1. Pie diagrams are used to show the break-up of a whole into parts.
2. Histogram and frequency polygon are for continuous frequency distributions.

Answer: Mode = 3 Median − 2 Mean = 3 × 28 − 2 × 31 = 84 − 62 = 22

Teacher's Note:
1. The relation Mode = 3 Median − 2 Mean holds for a moderately asymmetrical distribution.
2. Do not interchange median and mean in the formula.

Answer: Index numbers (price index numbers such as the Consumer Price Index).

Teacher's Note:
1. An index number measures the relative change in a variable over time.
2. Price index numbers compare the price level of a current year with a base year.

Answer: The base year is the year with which the prices (or quantities) of other years are compared; its index number is taken as 100.

Teacher's Note:
1. The base year should be a normal year, free from abnormal events like war or famine.
2. Its index value is always 100.

Answer: Rate of inflation = \( \dfrac{\text{CPI of current year} - \text{CPI of previous year}}{\text{CPI of previous year}} \times 100 \)

Teacher's Note:
1. Inflation is the percentage change in the price index between two periods.
2. Subtract first and then divide by the previous year's index, not the current one.

Answer: Take assumed mean A = 13 and common factor C = 1 (no common factor exists), so d = X − 13.
1. d values: 2, −5, −3, −1, 0, 22, 5, 1.
2. fd values: 16, −50, −24, −25, 0, 198, 30, 8. Σfd = 153.
3. N = Σf = 88.
4. Mean = A + Σfd/N × C = 13 + 153/88 = 13 + 1.74
Mean ≈ 14.74

Teacher's Note:
1. Here the values have no common factor, so the step deviation method reduces to the shortcut (assumed mean) method.
2. Keep the signs of d carefully, since a single sign error changes Σfd.

Answer: Females: 16 in all, including 1 lady teacher, so female students = 15 (peons are all male). Male students = 60 − 15 = 45. Male teachers = 14 − 1 = 13.

Teacher's Note:
1. First work out the missing figures (female students, male students, male teachers) and then build a two-way table.
2. Always give a title and check that the row and column totals agree.

Answer: Paasche's index = \( \dfrac{\sum p_1 q_1}{\sum p_0 q_1} \times 100 \)
1. Σp₁q₁ = 12×8 + 20×5 + 16×3 + 11×6 = 96 + 100 + 48 + 66 = 310.
2. Σp₀q₁ = 10×8 + 15×5 + 8×3 + 9×6 = 80 + 75 + 24 + 54 = 233.
3. Paasche's index = 310/233 × 100 = 133.05 (approximately)

Teacher's Note:
1. Paasche's method uses current year quantities as weights for both years.
2. Do not use base year quantities, which would give Laspeyres' index.

Answer: Median
1. Cumulative frequencies: 15, 26, 38, 45, 55, 63. N = 63, N/2 = 31.5.
2. The median class is 20-30 (cf just above 31.5 is 38). l = 20, cf = 26, f = 12, h = 10.
3. Median = l + (N/2 − cf)/f × h = 20 + (31.5 − 26)/12 × 10 = 20 + 4.58 = 24.58 years
Mode
4. The highest frequency is 15, so the modal class is 0-10. l = 0, f₁ = 15, f₀ = 0 (no class before), f₂ = 11, h = 10.
5. Mode = l + (f₁ − f₀)/(2f₁ − f₀ − f₂) × h = 0 + 15/(30 − 0 − 11) × 10 = 150/19 = 7.89 years

Teacher's Note:
1. Find N/2 and locate the median class from the cumulative frequency before applying the formula.
2. For the first class the frequency before it is taken as zero in the mode formula.

Answer: Base year quantities are the weights.
(i) Aggregative Expenditure method
1. Σp₁q₀ = 20×8 + 40×6 + 32×20 + 44×5 = 160 + 240 + 640 + 220 = 1260.
2. Σp₀q₀ = 10×8 + 35×6 + 30×20 + 40×5 = 80 + 210 + 600 + 200 = 1090.
3. CPI = 1260/1090 × 100 = 115.60
(ii) Family Budget method (weights W = p₀q₀, price relative R = p₁/p₀ × 100)
4. A: W = 80, R = 200, WR = 16000. B: W = 210, R = 114.29, WR = 24000. C: W = 600, R = 106.67, WR = 64000. D: W = 200, R = 110, WR = 22000.
5. ΣW = 1090, ΣWR = 126000.
6. CPI = ΣWR/ΣW = 126000/1090 = 115.60
Both methods give the same value, as they must when base year quantities are the weights.

Teacher's Note:
1. In the family budget method the weights are base year expenditures (p₀q₀), so the answer matches the aggregative method.
2. Use only base year quantities; 2021 quantities are not needed for a Laspeyres type CPI.

Answer: 1. Growth in the resources of the economy (more labour, capital, land etc.).
2. Technological improvement, which raises productivity of the existing resources.

Teacher's Note:
1. A rightward shift means the economy can now produce more of both goods, so it is economic growth.
2. A mere movement along the curve is a change in product mix, not a shift.

Answer: (b) It is necessary. Necessities have few substitutes and cannot be given up, so demand hardly responds to price.

Teacher's Note:
1. Necessities have inelastic demand while luxuries have elastic demand.
2. A good whose use can be postponed has elastic demand, so option (c) is wrong.

Answer: False. For an inferior good, demand falls as income rises, so the income effect is negative.

Teacher's Note:
1. For a normal good the income effect is positive; for an inferior good it is negative.
2. Do not confuse the income effect with the price effect.

Answer: p₁x₁ + p₂x₂ = M, where p₁ and p₂ are the prices of goods 1 and 2, x₁ and x₂ are their quantities and M is the consumer's income.

Teacher's Note:
1. The budget line shows all bundles that cost exactly the consumer's income.
2. Bundles below the line cost less than M, and those above it are unaffordable.

Answer: (d) Rs 330. TVC = AVC × output = 3 × 100 = Rs 300; TC = TFC + TVC = 30 + 300 = Rs 330.

Teacher's Note:
1. First convert average variable cost to total variable cost by multiplying with output.
2. Total cost is TFC plus TVC, so do not stop at TVC (Rs 300).

Answer: False. AP rises as long as MP is above AP, even if MP is falling; AP falls only when MP is below AP.

Teacher's Note:
1. The MP curve cuts the AP curve at the maximum point of AP.
2. Compare MP with AP, not MP with its own earlier value.

Answer: An upward sloping straight line starting from the origin (TR = P × q with price constant).

Teacher's Note:
1. Since the firm is a price taker, each extra unit adds the same revenue (MR = P).
2. Under monopoly or monopolistic competition TR is not a straight line.

Answer: Extension of demand is a rise in quantity demanded due to a fall in the price of the good itself, other factors constant (movement along the demand curve). Increase in demand is a rise in demand at the same price due to other factors like income or tastes (rightward shift of the demand curve).

Teacher's Note:
1. The cause is the key difference: own price for extension, other determinants for increase.
2. Remember that extension is a movement along the curve and increase is a shift of the curve.

Answer: Buffer stock is the stock of foodgrains that the government purchases and holds, at the minimum support price, to release in the market when prices rise too much; it is used to stabilise prices.

Teacher's Note:
1. Buffer stock is linked with the price floor (minimum support price) policy.
2. Government buys when the price is low and sells when the price is high.

Answer: (b) Excess supply. At a price above equilibrium, quantity supplied exceeds quantity demanded, so price tends to fall.

Teacher's Note:
1. Above equilibrium price means a surplus; below equilibrium price means a shortage.
2. Excess supply pushes the price down towards equilibrium.

Answer: 1. Downward sloping: since resources are limited, more of one good can be produced only by producing less of the other, so the curve slopes down from left to right.
2. Concave to the origin: the marginal opportunity cost (marginal rate of transformation) rises, because resources are not equally efficient in producing both goods. More and more of one good has to be given up for each additional unit of the other.
3. Every point on the curve shows full and efficient use of resources; points inside the curve show underutilisation and points outside are unattainable with the given resources and technology.

Teacher's Note:
1. Link each property to a reason: scarcity for the downward slope and increasing opportunity cost for concavity.
2. Mention what the points inside and outside the curve represent to score full marks.

Answer: 1. Nature of the good: necessities (salt, medicines) have inelastic demand, while luxuries have elastic demand.
2. Availability of substitutes: the more close substitutes a good has, the more elastic is its demand, since consumers can easily switch.
3. Share of income spent: goods that take a large part of the budget (like a car) have more elastic demand than goods that take a very small part (like salt).
(Other factors: time period, possibility of postponing use.)

Teacher's Note:
1. Give each factor with a one-line reason and an example.
2. Say clearly which way each factor pushes elasticity, i.e. more or less elastic.

Answer: P₀ = 5, P₁ = 10, so ΔP = 5. Q₀ = 100, Q₁ = 120, so ΔQ = 20.
Es = (Percentage change in quantity supplied)/(Percentage change in price)
1. % change in quantity = 20/100 × 100 = 20%.
2. % change in price = 5/5 × 100 = 100%.
3. Es = 20/100 = 0.2
Supply is inelastic (Es < 1).

Teacher's Note:
1. Calculate both percentage changes on the original (initial) values.
2. Interpret the answer: a value below 1 means supply is inelastic.

Answer: TFC = AFC × output = 5 × 4 = Rs 20 at every level of output (fixed cost does not change). TVC = TC − TFC; AVC = TVC/Q; AFC = TFC/Q; AC = TC/Q; MC = change in TC.

Teacher's Note:
1. Find TFC first, because everything else follows from it.
2. AC must equal AFC + AVC in every row, which is a good check.

Answer: Statement: as the quantity of a variable factor is increased, keeping the other factors fixed, the marginal product of the variable factor first rises, then falls and finally becomes negative.

Teacher's Note:
1. Always state that one factor is fixed, and that this is a short run law.
2. Show all three stages in the table and tie each stage to the behaviour of MP and TP.