CUET UG Booster Economics 4 (D1)

Under perfect competition, a firm is a price taker, meaning the market price remains constant regardless of the quantity sold. Therefore, TR = p × q where p is constant and q is output. Since Total Revenue increases proportionately with every additional unit sold, the Total Revenue curve is an upward-sloping straight line passing through the origin. Both the Assertion and the Reason are correct, and the Reason correctly explains why the Total Revenue curve has this shape. Option C is correct because both statements are true and the Reason directly explains the Assertion. Option A is incorrect because both statements are true. Option B is incorrect because the Reason is also true. Option D is incorrect because the Assertion is true.

The NCERT follows a logical analytical sequence: 1. Specify the market environment (perfect competition). 2. Set up the firm\'s profit-maximisation problem. 3. Derive the individual firm\'s supply curve based on profit-maximising output. 4. Aggregate all individual supply curves to obtain the market supply curve. Only Option C correctly represents this sequence.

Perfect competition assumes a large number of buyers, ensuring that each buyer purchases only a very small fraction of total market output. If this assumption is violated, a sufficiently large buyer could influence market demand and potentially negotiate or affect the market price. This would violate the price-taking assumption. Option D is correct because the immediate consequence is increased buyer market power. Option A is incorrect because product homogeneity is unaffected. Option B is incorrect because entry conditions remain unchanged. Option C is incorrect because information availability is unrelated to the number of buyers.

Since there are numerous sellers, each firm\'s contribution to total market supply is extremely small. As a result, no firm can create scarcity or influence the market price by changing its own output. Therefore, each firm accepts the market price as given and behaves as a price taker. Option B is correct because the inability to influence price defines price-taking behaviour. Option A is incorrect because firms maximise profit, not output. Option C is incorrect because product differentiation is absent. Option D is incorrect because perfect competition assumes perfect information rather than information asymmetry.

If products become heterogeneous, buyers can distinguish among firms\' products. Consequently: Statement I becomes false because buyers can no longer obtain identical products from every seller. Statement II also fails because differentiated products give firms some market power, so the firm\'s demand curve is no longer perfectly elastic. Statement III remains true because firms still seek to maximise profits regardless of market structure. Therefore, Statements I and II only fail. Option C is correct. The remaining options incorrectly include or exclude Statement III.

Under perfect competition, all firms sell homogeneous products, and buyers possess perfect information. Therefore, if one firm charges a higher price, buyers simply purchase the identical product from another firm without any inconvenience. Since the products are identical, there are no adjustment problems when switching sellers. Option A is correct because the NCERT specifically mentions that no \"adjustment\" problems arise. Option B is incorrect because market failure refers to a different economic concept. Option C is incorrect because profit fluctuations are not the reason buyers can switch easily. Option D is incorrect because legal barriers are unrelated to product homogeneity.

Each market condition leads to a specific consequence: 1 → b : Free entry means firms can easily enter the market. 2 → c : When Price > AC, firms earn super-normal profit, attracting new firms. 3 → a : If Price < minimum AVC, firms shut down in the short run. 4 → d : Normal profit provides no incentive for entry or exit. Therefore, Option D correctly matches every pair.

In the long run, firms under perfect competition remain in the market only if they can earn at least normal profit. If they cannot cover their costs, they leave the market because free exit is one of the assumptions of perfect competition. Exiting prevents firms from continuing to incur losses. Option B is correct because free exit allows firms to avoid persistent losses. Option A is incorrect because government subsidies are not assumed. Option C is incorrect because firms do not continue producing indefinitely at a loss. Option D is incorrect because product differentiation is not possible under perfect competition.

Perfect competition assumes that buyers possess complete information regarding prices and product quality. If buyers lack this information, some firms could charge prices above the prevailing market price because uninformed buyers would not know that cheaper alternatives exist. This weakens the price-taking nature of the market. Option D is correct because imperfect information enables firms to exploit uninformed buyers. Option A is incorrect because imperfect information alone does not create a monopoly. Option B is incorrect because unchanged prices would not cause all buyers to leave. Option C is incorrect because production costs are unrelated to information availability.

The combination of homogeneous products and perfect market transparency means buyers can easily compare prices and switch to another seller without any adjustment problems. Consequently, an individual firm cannot charge a price above the market price. It therefore faces a perfectly elastic demand curve, represented by a horizontal price line. Option C is correct because this is the direct consequence of the assumptions of perfect competition. Option A is incorrect because price discrimination is impossible under perfect competition. Option B is incorrect because demand is perfectly elastic, not perfectly inelastic. Option D is incorrect because the firm\'s marginal revenue equals price and does not slope downward.

A perfectly competitive firm faces a perfectly elastic demand curve, meaning it can sell any quantity at the prevailing market price. Since every additional unit is sold at the same price, the increase in Total Revenue from selling one more unit is always equal to the market price. Therefore, MR = Price = Rs 10 The output level (q = 5) does not affect Marginal Revenue because price remains constant. Option A is correct because MR always equals the market price under perfect competition. Option B is incorrect because MR is not half of the market price. Option C is incorrect because Rs 50 represents Total Revenue at 5 units, not Marginal Revenue. Option D is incorrect because Marginal Revenue is positive as long as output is sold.

A price-taking buyer understands that every seller is willing to sell only at the prevailing market price because identical products are available from many firms. Therefore, requesting a lower price is ineffective, as sellers can easily sell their products to other buyers at the market price. Option B is correct because buyers recognise that offering a lower price results in no purchase. Option A is incorrect because bargaining is inconsistent with perfect competition. Option C is incorrect because an individual buyer cannot influence market price. Option D is incorrect because fairness is unrelated to price-taking behaviour.

The passage explains that a perfectly competitive firm can sell as many units as it wishes at the prevailing market price. Therefore, reducing the price below the market price does not increase sales, since the firm already faces a perfectly elastic demand curve at the market price. Lowering the price would simply reduce revenue without increasing quantity sold. Option D is correct because the firm already sells all desired output at the market price. Option A is incorrect because price does not determine total cost. Option B is incorrect because the government does not prohibit lower prices. Option C is incorrect because product quality is identical across firms.

The passage explains that a perfectly competitive firm always sets its price equal to the market price because charging more results in zero sales, while charging less is unnecessary. This means the firm\'s pricing decision is entirely determined by the market, confirming that it has no individual control over price. Option B is correct because it reflects the price-taking nature of the firm. Option A is incorrect because firms possess no pricing power. Option C is incorrect because output depends on profit maximisation, not pricing. Option D is incorrect because an individual firm cannot manipulate market demand.

A profit-maximising firm chooses output where Marginal Revenue (MR) equals Marginal Cost (MC). However, this condition alone is insufficient. For the chosen output to represent maximum profit, the Marginal Cost curve must be non-decreasing (typically rising) at the equilibrium point. If MC were falling at q0q_0q0​, producing additional output could further increase profit, indicating that q0q_0q0​ is not the true profit-maximising level. Option A is correct because it describes the second-order condition for profit maximisation. Option B is incorrect because decreasing MC does not necessarily imply losses. Option C is incorrect because the shape of the MC curve is unrelated to the price-taking assumption. Option D is incorrect because Total Revenue remains positive when output is sold.

A firm\'s objective under perfect competition is to maximize profit, where: π = TR − TC The firm compares Total Revenue (TR) and Total Cost (TC) for different output levels and chooses the quantity where their difference is greatest. This is the profit-maximising level of output. Option C is correct because profit is defined as TR − TC. Option A is incorrect because profit is not calculated by adding TR and TC. Option B is incorrect because profit is not measured as a ratio. Option D is incorrect because firms generally produce only when positive revenue can be earned.

Under perfect competition, the demand curve facing an individual firm is perfectly elastic, meaning the market price remains constant regardless of output. Therefore, TR = p × q where p is constant. The slope of the Total Revenue curve equals: ΔTR / ΔQ = p which is also the firm\'s Marginal Revenue (MR). Option C is correct because the slope of the TR curve is constant and equal to the market price. Option A is incorrect because the slope does not vary. Option B is incorrect because zero is the slope of the firm\'s demand curve, not the Total Revenue curve. Option D is incorrect because Average Cost has no relationship with the slope of the TR curve.

The NCERT explains that the firm\'s demand curve under perfect competition is a horizontal price line because the market price remains fixed. The line intersects the y-axis at the value p, which represents the market price. Since AR = MR = Price, the horizontal line remains at the height p. Option D is correct because the vertical intercept equals the market price. Option A is incorrect because profit is not measured on the demand curve. Option B is incorrect because Marginal Cost is a different curve. Option C is incorrect because Average Variable Cost is unrelated to the price line.

The NCERT acknowledges that assuming firms are ruthless profit maximisers may not perfectly describe real-world behaviour. However, economists adopt this assumption because it simplifies the analysis of production and output decisions, allowing the development of clear models for firm behaviour under perfect competition. Option A is correct because simplification is the reason for the assumption. Option B is incorrect because firms do not always behave exactly as the assumption suggests. Option C is incorrect because supply curves are still required. Option D is incorrect because profit maximisation is not legally mandated.

The perfect competition model is based on several simplifying assumptions that may not hold in real markets. Statement I is correct because perfect information rarely exists in reality. Statement II is correct because many real markets have legal, financial, or technological barriers to entry. Statement III is incorrect because the model assumes firms maximise profit (TR − TC), not simply revenue. Therefore, Statements I and II only are correct. Option D is the correct answer. The remaining options incorrectly include Statement III or exclude a correct statement.