EconomicsCBSE Class 12 · Open Economy Macroeconomics

Foreign Exchange Rate Systems: Fixed, Flexible and Managed Floating (Class 12)

Updated 15 October 2026 · Fact-checked

The foreign exchange rate is the price of one currency in terms of another, e.g. ₹84 per dollar. Under a flexible system it is set by demand and supply of foreign exchange; under a fixed system the government fixes it and the central bank intervenes; under managed floating, the market sets it but the central bank intervenes to moderate swings.

When demand for dollars rises, D shifts right to D′, the ₹/USD rate climbs from e* to e₁, and the rupee depreciates.

Illustration drawn for QuestionBuddy.

Understand Foreign Exchange Rate Systems

Foreign exchange market: where national currencies are traded; participants are commercial banks, foreign exchange brokers, authorised dealers and monetary authorities. It is world-wide.

Exchange rate: the price of one currency in terms of another (e.g. ₹ per USD).

Demand for foreign exchange (why residents want dollars): to buy foreign goods and services (imports, travel), to send gifts abroad, to buy foreign financial assets. A higher exchange rate makes imports costlier in rupees, so demand falls: the demand curve slopes downward.

Supply of foreign exchange (why dollars come in): exports bought by foreigners, gifts and transfers from abroad, foreigners buying domestic assets. A higher exchange rate makes Indian goods cheaper for foreigners, so exports and supply rise: the supply curve slopes upward (actual effect depends on elasticities).

Diagram checklist (flexible rate). Y-axis: exchange rate (₹/USD); X-axis: quantity of dollars. Downward-sloping D, upward-sloping S; equilibrium rate e* and quantity q* at the intersection. For an increase in demand (more travel abroad), D shifts right to D′; the rate rises from e* to e₁: rupee depreciates.

Depreciation vs appreciation (flexible system). A rise in the ₹/USD rate (more rupees per dollar) is depreciation of the rupee; a fall is appreciation. Under a fixed system, a government-made increase in the rate is devaluation; a decrease is revaluation.

Other influences (flexible market). Speculation (expected appreciation of a currency raises its demand now); interest rate differential (higher interest at home attracts funds and usually appreciates the home currency); income (faster domestic income growth raises imports and tends to depreciate the currency); long run: purchasing power parity — rates adjust so the same good costs the same everywhere (ignoring transport and trade barriers).

Fixed exchange rate. The government fixes the rate. If it is fixed above the market rate (rupee cheaper, to promote exports), there is an excess supply of dollars; the RBI buys dollars, accumulating reserves. If fixed below, there is excess demand for dollars; the RBI must sell from reserves, or a black market may develop.

Merits and demerits.

Fixed: gives certainty if credible, but needs large reserves; if reserves look inadequate, expectations of devaluation can trigger a speculative attack (as before the collapse of the Bretton Woods system).
Flexible: more flexibility, no need for large reserves; movements in the rate automatically correct BoP surpluses and deficits; independent monetary policy. (Its drawback is greater uncertainty from day-to-day swings.)

Managed floating ('dirty floating'). A mix: the market sets the rate (float), but central banks buy and sell currencies to moderate movements when they think it appropriate (managed). Official reserve transactions are therefore not zero. The world has moved to this system without any formal agreement.

Foreign Exchange Rate Systems: key facts

Exchange rate: Exchange rate = Price of one unit of foreign currency in domestic currency (₹/USD); Higher number = weaker rupee.
Depreciation %: % rise in price of USD = (New rate − Old rate) ÷ Old rate × 100; ₹75 → ₹84: 12%.
Rupee cost of imports: ₹ price = USD price × exchange rate; Rises when rupee depreciates.
Dollar price of exports: USD price = ₹ price ÷ exchange rate; Falls when rupee depreciates.
PPP (long run): Exchange rate = Domestic price of a good ÷ Foreign price of the same good; Ignoring transport costs and trade barriers.

How to answer Foreign Exchange Rate Systems questions

Exchange-rate questions include 1-mark terms (depreciation, devaluation), 3-4 mark diagram explanations of market determination, and merits/demerits of systems.

1Identify the system: market (flexible), government-fixed, or market with intervention (managed floating).
2For a change in demand or supply, shift the right curve and read the new rate; more ₹ per USD = depreciation.
3Use 'depreciation/appreciation' for market changes and 'devaluation/revaluation' for government changes under fixed rates.
4For effects on trade: depreciation makes imports dearer in rupees and exports cheaper in dollars.
5Draw and label the diagram: axes, D and S curves, equilibrium, shift and new equilibrium.

Foreign Exchange Rate Systems in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Depreciation and your shopping

Suppose the rupee moves from ₹75 to ₹84 per dollar. You want a US-made gadget priced at USD 40, while an Indian handicraft exporter sells a lamp for ₹4,200.

How do the gadget's rupee price and the lamp's dollar price change?

Try it first, then show the solutionSolution

Gadget: 40 × 75 = ₹3,000 before; 40 × 84 = ₹3,360 after.
Lamp: 4,200 ÷ 75 = USD 56 before; 4,200 ÷ 84 = USD 50 after.
The rupee has depreciated by 12% against the dollar.

Answer: The gadget becomes ₹360 costlier, while the lamp becomes USD 6 cheaper for American buyers. Depreciation discourages imports and encourages exports.

Memory hook: Weak rupee: imports pinch, exports win.

Speculation

Imagine traders expect the pound to rise from ₹100 to ₹106 within a month. A trader buys £2,000 for ₹2,00,000.

What profit does she expect, and how does such behaviour affect the exchange rate now?

Try it first, then show the solutionSolution

Expected value: 2,000 × 106 = ₹2,12,000.
Expected profit = ₹12,000.
Many traders buying pounds raise demand for pounds now.

Answer: She expects ₹12,000 profit. When many traders act on the same expectation, demand for pounds rises today, pushing up the rupee-pound rate: expectations become self-fulfilling.

Memory hook: Expect it, buy it, cause it.

Tricks to remember Foreign Exchange Rate Systems

Short memory aids. Say each one aloud once, then use it on a question the same day.

Market-made vs government-made
Depreciation/appreciation = market-made (flexible); devaluation/revaluation = government-made (fixed).
Use it when: The commonest 1-mark trap.
Up the rate, down the rupee
A higher ₹/USD number means a weaker rupee.
Use it when: Reading exchange-rate changes.
Managed floating = float + manage
Market sets the rate; the central bank smooths the waves.
Use it when: Defining managed floating.

Foreign Exchange Rate Systems: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Devaluation · 1 mark · MCQBoard level

Under a fixed exchange rate system, a government action that raises the price of foreign currency in domestic currency is called:
(a) Depreciation
(b) Appreciation
(c) Devaluation
(d) Revaluation

Try it first, then show the solutionSolution

Government-made increase in the rate under fixed system = devaluation.

Answer: (c) Devaluation

Example 2: Market determination · 4 marks · Short answerBoard level

Explain with a diagram how the exchange rate is determined in a free (flexible) foreign exchange market. (4 marks)

Try it first, then show the solutionSolution

Demand: imports, gifts abroad, foreign assets; slopes down (1 mark).
Supply: exports, transfers in, foreign purchase of domestic assets; slopes up (1 mark).
Equilibrium at D = S (1 mark).
Diagram labelled (1 mark).

Answer: Demand for foreign exchange arises from imports, gifts abroad and purchase of foreign assets; a higher rate makes imports costlier, so the demand curve slopes downward. Supply comes from exports, transfers from abroad and foreigners buying domestic assets; a higher rate makes exports cheaper abroad, so supply slopes upward. The equilibrium rate e* (and quantity q*) is where D = S. Diagram: ₹/USD on the Y-axis, quantity of USD on the X-axis, D and S intersecting at e*.

Example 3: Depreciation numbers · 3 marks · Short answerHarder board level

The rupee moves from ₹75 to ₹84 per dollar. Calculate the percentage rise in the price of the dollar and the percentage fall in the dollar value of a rupee. Is this depreciation or devaluation if the system is flexible? (3 marks)

Try it first, then show the solutionSolution

(84 − 75) ÷ 75 × 100 = 12%.
Rupee value: 1/75 → 1/84; change = 75/84 − 1 ≈ −10.7%.
Market change in a flexible system: depreciation.

Answer: The dollar's price rises by 12%; the rupee's value in dollars falls by about 10.7%. In a flexible system, this is depreciation of the rupee.

Example 4: Fixed rate and intervention · 3 marks · Short answerHarder board level

The market rate is ₹75 per dollar, but the government fixes it at ₹80 to promote exports. At ₹80, dollars supplied are 520 million and dollars demanded 470 million. What must the RBI do, and what happens to its reserves? (3 marks)

Try it first, then show the solutionSolution

Excess supply of dollars = 520 − 470 = 50 million.
RBI buys 50 million dollars with rupees.
Reserves rise by 50 million dollars (as long as it keeps intervening).

Answer: There is an excess supply of USD 50 million at ₹80. The RBI buys these dollars, so its foreign exchange reserves rise by USD 50 million; it must keep accumulating reserves as long as it holds the rate above the market level.

Example 5: Purchasing power parity · 4 marks · Short answerHOTS / competency

A school bag costs ₹1,800 in India and USD 24 in the USA. (i) What exchange rate does PPP suggest? (ii) If Indian prices rise 10% and US prices 20%, what will the PPP rate become, and which currency depreciates? (4 marks)

Try it first, then show the solutionSolution

(i) 1,800 ÷ 24 = ₹75 per USD.
(ii) New prices: ₹1,980 and USD 28.80; 1,980 ÷ 28.80 = ₹68.75 per USD.
Fewer rupees per dollar: dollar depreciates, rupee appreciates.

Answer: (i) ₹75 per dollar. (ii) ₹68.75 per dollar; because US prices rose faster, the dollar depreciates (the rupee appreciates) in the long run, according to PPP.

Example 6: Case: managed floating · 3 marks · Case-basedHOTS / competency

Suppose a surge in oil prices sharply raises India's import bill, and the rupee slides for three weeks. The RBI sells dollars from its reserves on some days to smooth the slide but announces no target rate. (i) Which exchange-rate system does this describe? (ii) Why are official reserve transactions not zero here? (iii) Give one merit of a flexible rate that this system keeps. (3 marks)

Try it first, then show the solutionSolution

(i) Managed floating (dirty floating).
(ii) The RBI intervenes by selling dollars.
(iii) Market largely sets the rate, so BoP gaps are corrected automatically and huge reserves aren't needed to defend a fixed level.

Answer: (i) Managed floating. (ii) Because the central bank buys and sells foreign currency to moderate movements, official reserve transactions are not zero. (iii) The rate is still mainly market-determined, so movements help correct BoP imbalances and the country need not hold very large reserves to defend a fixed level.

Where students lose marks in Foreign Exchange Rate Systems

The slips examiners see most often, and what to write instead.

Mistake: Using devaluation for a market fall
Terms confused.
Wrong working
The rupee was devalued as demand for dollars rose.
Right working
In a flexible market it depreciated; devaluation is a government act under fixed rates.
Do this: Market-made vs government-made.
Usually costs: 1 mark.
Mistake: Reading a higher ₹/USD rate as a stronger rupee
Direction confusion.
Wrong working
₹75 → ₹84: rupee appreciated.
Right working
More rupees per dollar: rupee depreciated.
Do this: Up the rate, down the rupee.
Usually costs: 1 mark.
Mistake: Unlabelled diagram
Axes and curves missing.
Wrong working
Two crossing lines.
Right working
Y: ₹/USD; X: quantity of USD; D (down), S (up); e*, q*; shift and new rate.
Do this: Label everything.
Usually costs: 1 mark.

Exam tips

Exchange-rate systems and the forex market carried about six tagged items in the PYQ bank.
Box 6.2 on international exchange-rate experience is out of the 2026-27 syllabus.
Always draw the demand-supply diagram for 'determination' questions.

Practice questions on Foreign Exchange Rate Systems

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
In a flexible exchange rate system, a rise in the demand for dollars (other things constant) will:
(a) appreciate the rupee
(b) depreciate the rupee
(c) devalue the rupee
(d) leave the rate unchanged
Hint
Price of USD rises.
Answer
(b) depreciate the rupee
Q2 · 1 mark · Short answerBoard level
Define managed floating exchange rate. (1 mark)
Hint
Float + manage.
Answer
A system in which the exchange rate is mainly market-determined but the central bank buys and sells foreign currency to moderate movements when it considers this appropriate (dirty floating).
Q3 · 3 marks · Short answerBoard level
State three sources each of demand for and supply of foreign exchange. (3 marks)
Hint
Imports vs exports.
Answer
Demand: imports of goods and services, sending gifts abroad, purchase of foreign assets. Supply: exports, gifts/transfers from abroad, foreigners buying domestic assets.
Q4 · 2 marks · Short answerHarder board level
Distinguish between depreciation and devaluation. (2 marks)
Hint
Market vs government.
Answer
Depreciation: a fall in the value of domestic currency (rise in the exchange rate) due to market forces under a flexible system. Devaluation: a deliberate increase in the exchange rate by the government under a fixed system.
Q5 · 2 marks · Short answerHarder board level
State two merits of a flexible exchange rate system. (2 marks)
Hint
Reserves, BoP, monetary policy.
Answer
Any two: no need to hold large foreign exchange reserves; exchange-rate movements automatically correct BoP surpluses and deficits; independence in monetary policy, since no intervention is needed to maintain the rate.
Q6 · 3 marks · Short answerHarder board level
What is a speculative attack on a currency, and why are fixed rates prone to it? (3 marks)
Hint
Doubtful reserves.
Answer
Under fixed rates, governments use reserves to cover BoP deficits. If people believe reserves are inadequate, they expect devaluation and buy foreign currency aggressively, forcing the government to devalue: a speculative attack. Fixed rates depend on credibility, so doubts about reserves make them vulnerable.
Q7 · 1 mark · Assertion-reasonHarder board level
Assertion (A): A rise in domestic interest rates often leads to appreciation of the domestic currency.
Reason (R): Higher interest rates attract foreign funds, raising demand for the domestic currency.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Hint
Interest rate differential.
Answer
(a) Both A and R are true and R is the correct explanation of A.
Q8 · 3 marks · Short answerHarder board level
How does an increase in foreign tourists visiting India affect the rupee-dollar rate under a flexible system? Explain with the curves involved. (3 marks)
Hint
Supply of dollars.
Answer
Foreign tourists spend dollars in India (export of tourist services), increasing the supply of dollars. The supply curve shifts right; at the old rate there is excess supply, so the ₹/USD rate falls: the rupee appreciates and the dollar depreciates.
Q9 · 3 marks · Short answerHOTS / competency
Suppose a government fixes the rupee below the market rate (making the rupee costlier) to cut the cost of imported oil. Analyse the consequences. (3 marks)
Hint
Excess demand for dollars.
Answer
At a rate below the market level, the demand for dollars exceeds supply. The RBI must sell dollars from its reserves to meet the excess demand; reserves fall continuously. If reserves run short, a black market for dollars may develop, exports become less competitive, and doubts about reserves can invite a speculative attack and eventual devaluation.
Q10 · 3 marks · Short answerHOTS / competency
A country's income grows much faster than that of its trading partners. Under a flexible rate, what is likely to happen to its currency? Explain. (3 marks)
Hint
Imports grow faster.
Answer
Faster income growth raises spending, including on imports, so demand for foreign currency rises faster than its supply from exports (partners' incomes are growing more slowly). The demand curve for foreign exchange shifts right more than supply, so the domestic currency tends to depreciate, other things equal.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.What is the foreign exchange rate?Show answer
The price of one currency in terms of another.
2.Rate falls from ₹84 to ₹80 per USD: rupee appreciates or depreciates?Show answer
Appreciates.
3.Revaluation happens under which system?Show answer
Fixed exchange rate system.
4.Another name for managed floating?Show answer
Dirty floating.
5.Which theory predicts long-run rates from price levels?Show answer
Purchasing power parity.

Foreign Exchange Rate Systems: frequently asked questions

What are the types of exchange rate systems in Class 12?

Fixed, flexible (floating) and managed floating exchange rate systems.

How is the exchange rate determined in a free market?

By the intersection of the demand for and supply of foreign exchange.

What is the difference between depreciation and devaluation?

Depreciation is a market-driven fall in a currency's value under flexible rates; devaluation is a government decision to lower it under fixed rates.

What is managed floating?

A system where the market mainly sets the rate but the central bank intervenes to moderate sharp movements.