General Studies
BRICS Nations — Remember "BRICS" itself: Brazil, Russia, India, China, South Africa. Recently expanded to BRICS+ with UAE, Saudi Arabia, Egypt, Ethiopia, Iran (2024).
Nobel Prize Categories — Physics Chemistry Medicine Literature Peace Economics = "Please Come My Love, Please Eat" (6 categories total).
Five-Year Plan Eras — 1st Plan (1951) focused on Agriculture, 2nd on Industry, 3rd on self-sufficiency. Remember: A-I-S (Agriculture → Industry → Self-reliance) for the foundational plans.
Fiscal vs Monetary Policy — Fiscal = Finance Ministry (taxes, spending); Monetary = Money Supply (RBI controls interest rates, CRR, SLR). Different controllers, different tools.
Development Indicators — HDI has 3 components: Health (life expectancy), Education (schooling years), Income (GNI per capita). Remember HEI = Height of development.
External Sector Terms — CAD (Current Account Deficit) = Trade + Services + Transfers. FAD (Fiscal Deficit) = Government spending minus revenue. CArs go outside (external), FAmily stays home (internal budget).
Indian Economy
CRR vs SLR — CRR = Cash with RBI (liquid, no interest); SLR = Securities in government bonds (earns interest). CRR is Cash Reserve, SLR is Securities/Liquid Ratio.
Direct vs Indirect Tax — Direct tax: burden cannot shift (income tax, wealth tax). Indirect tax: burden shifts to consumer (GST, customs). "Direction" matters—direct stays, indirect moves.
Repo vs Reverse Repo — Repo = RBI lends to banks (banks repurchase); Reverse Repo = Banks lend to RBI (RBI repurchases). Repo increases liquidity, Reverse Repo absorbs it.
Agricultural Seasons — Kharif = Khan (monsoon, June-Oct): rice, cotton. Rabi = Rain-after (winter, Oct-March): wheat, mustard. Zaid = Zest/summer (March-June): cucumber, watermelon.
Tamil Nadu — History, Culture, Society & Administration
Sangam Age Divisions — Three Sangams: 1st (lost), 2nd (lost), 3rd Sangam at Madurai produced classics. Remember "Third Time's the Charm"—only 3rd Sangam literature survived.
Tamil Nadu Classical Dances — Bharatanatyam uses Bhava (expression), Raga (melody), Tala (rhythm) = BRT formula. Originated in temples, Thanjavur school most famous.
Chola Bronzes — Nataraja, Ardhanarisvara, Somaskanda = NAS trinity. Chola bronze casting peaked 10th-12th century CE under Raja Raja and Rajendra Chola.
Tamil Festivals Order — Pongal (Jan), Chittirai (April-May), Aadi (July-Aug), Navaratri (Sep-Oct), Deepavali (Oct-Nov) = PCAND through the year.
Aptitude and Mental Ability
Divisibility by 11 — Subtract alternate digit sums: (1st+3rd+5th...) − (2nd+4th+6th...). If result is 0 or divisible by 11, the number is divisible by 11. Quick check for large numbers.
LCM × HCF Formula — For two numbers: LCM × HCF = Product of the two numbers. If you know 3 values, instantly calculate the 4th. Saves 30+ seconds in exams.
Percentage Shortcuts — 10% = divide by 10; 5% = half of 10%; 15% = 10% + 5%. For 20%: divide by 5. Build from these bases instead of multiplying by 0.15, etc.
Time-Distance-Speed Triangle — Cover any one: Distance = Speed × Time; Speed = Distance/Time; Time = Distance/Speed. Triangle method: D on top, S and T below. Cover what you need.
Simple Interest Trick — SI = (P × R × T)/100. For quick mental math: If P=1000, R=10%, T=2 years → SI = 2000/100 = 200. Scale proportionally for different values.
Compound Interest vs SI Difference — For 2 years: CI − SI = PR²/10000 (when rate R% per annum). This difference is interest on first year's interest only. Instant calculation.
Dice Opposite Faces — Standard die: 1-6, 2-5, 3-4 are opposite pairs. Sum of opposite faces always equals 7. Visualize cube folding to solve dice rotation problems quickly.
Data Interpretation Approximation — Round numbers to nearest 10 or 100 first: 487 ≈ 500, 23.7% ≈ 25%. Calculate with round numbers, then adjust. DI tests speed over precision in most cases.