AICET for CITS cheat sheet

Absolute advantage: a country produces more output per unit input than its partner; comparative advantage: lower opportunity cost, which is the basis for mutually beneficial trade.

Opportunity cost of good X = units of good Y forgone ÷ extra units of X gained; the flatter the PPF slope, the lower that cost.

Terms of trade must lie strictly between the two domestic opportunity-cost ratios for both parties to gain from exchange.

Tariff effects on a small open economy: consumer surplus falls, producer surplus and government revenue rise, deadweight loss = production distortion + consumption distortion triangles.

Quota versus tariff: a quota transfers the equivalent rent to licence holders, so the importing country's welfare loss is generally larger than under an equal tariff.

Nominal tariff rate = (duty ÷ customs value) × 100; effective rate of protection accounts for input tariffs and exceeds the nominal rate when inputs enter duty-free.

Balance of trade = exports of goods − imports of goods; the current account adds services, income and unilateral transfers.

Elasticity rule (Marshall–Lerner): devaluation improves the trade balance only when the sum of export and import demand elasticities exceeds 1.

Infant-industry argument justifies temporary protection only if the learning cost is recouped and protection is time-bound; otherwise it becomes rent-seeking.

Incoterms 2020 risk transfer: EXW at seller's premises; FCA on handing to carrier; FOB when goods are on board; CFR/CIF on board with freight (and insurance under CIF) paid to destination; DAP at named place; DDP duty paid.

Only CIF and CIP require the seller to obtain insurance; under CIP the default cover is Institute Cargo Clauses (A), while CIF defaults to (C).

Documentary credit follows strict compliance: documents must match L/C terms exactly; banks deal in documents, not goods.

Bill of lading functions: receipt of goods, evidence of contract of carriage, and document of title enabling endorsement and transfer.

Shipping terms: gross weight includes packaging; volumetric (measurement) weight in tonnes = L × W × H (m) ÷ divisor per carrier rule; chargeable weight is the greater of actual and volumetric.

Customs value for ad valorem duty is normally transaction value (price actually paid or payable) plus adjustments such as freight and insurance where the tariff basis is CIF.

Export incentives and duty drawback require documentary linkage between imported inputs and exported output within the prescribed time limit.

A sight draft is payable on presentation; a usance (term) draft allows deferred payment, and acceptance by the drawee creates a banker's or trade acceptance.

Certificate of origin determines preferential tariff eligibility; a wrong HS classification changes both duty rate and origin rules applied.

Tolerance and limits: upper limit = basic size + upper deviation; lower limit = basic size + lower deviation; tolerance = upper limit − lower limit.

Allowance = minimum clearance = lower limit of hole − upper limit of shaft; a negative allowance denotes interference.

Cutting speed V = πDN ÷ 1000 (V in m/min, D in mm, N in rpm); rearrange N = 1000V ÷ (πD).

Feed and machining time: T = L ÷ (f × N), where L is total tool travel including approach and overtravel, f is feed per revolution.

Taper turning by swivel: tan(α) = (D − d) ÷ (2L); the compound slide is set to half the included angle.

Screw thread geometry: pitch = 1 ÷ threads per inch; metric thread depth ≈ 0.6134 × pitch; tap drill size ≈ major diameter − pitch.

Gear ratios: driver/driven product; for a simple train, ratio = product of driven teeth ÷ product of driver teeth, and output speed = input × (drivers ÷ drivens).

Stress σ = F ÷ A, strain ε = ΔL ÷ L, Young's modulus E = σ ÷ ε; shear stress in a rivet τ = F ÷ (πd²/4).

Turning and milling power: P (kW) = (F × V) ÷ 60000 with F in newtons and V in m/min; efficiency reduces available spindle power.

First-angle projection: the object sits between observer and plane, so the view from the front appears above the top view and the left-side view is placed on the right.

Third-angle projection: the plane sits between observer and object, so the top view is above the front view and the right-side view is on the right.

Line precedence: visible outlines over hidden lines, hidden lines over centre lines, centre lines over dimension and extension lines.

Scale = drawing length ÷ actual length; representative fraction is written as 1:n for reduction and n:1 for enlargement.

Dimensioning rules: dimensions go on the view showing the true shape, are not repeated, and the smallest dimension is placed nearest the feature.

Geometric tolerance symbols: straightness, flatness, circularity, cylindricity (form); parallelism, perpendicularity, angularity (orientation); position, concentricity, symmetry (location); runout.

Section views: hatching lines at 45° in thin continuous lines; adjacent parts are hatched in opposite directions; a half section shows one quarter removed.

Thread representation: external threads use thick crest and thin root lines; a threaded hole in section shows the minor diameter as a thick line.

Surface roughness Ra is the arithmetical mean deviation; lower Ra means a smoother surface, and the symbol is placed once with a general note if repeated.