Physics
Right-Hand Palm Rule for Force — Magnetic force direction: fingers point current direction, field lines enter palm, thumb shows force direction on conductor. For moving charge, use fingers for velocity instead of current.
CIVIL for AC Circuits — In a Capacitor, current (I) leads Voltage; in an Inductor, Voltage leads current (I). Helps remember phase relationships in AC circuits instantly.
Lenz's Law Memory — Induced current always opposes the change causing it. Think "nature is lazy"—it resists change. Thumb opposes motion in right-hand rule for induced current.
Photoelectric Equation Setup — KEmax = hν - φ. Remember "Energy IN minus Energy OUT." Photon energy minus work function equals leftover kinetic energy of ejected electron.
Escape Velocity Quick — ve = √(2GM/R) = √(2gR). For Earth: roughly 11.2 km/s. Mnemonic: "2 Good Rats" for the 2, g, R formula structure.
Kirchhoff's Laws Distinction — KCL (Current Law): "What comes IN must go OUT" (junction). KVL (Voltage Law): "Complete loop adds to ZERO" (closed path). Junction vs. loop.
Chemistry
Alcohol Oxidation Ladder — Primary alcohol → Aldehyde → Carboxylic acid. Secondary alcohol → Ketone (stops). Tertiary alcohol → No oxidation. Remember: 1°→2 steps, 2°→1 step, 3°→0 steps.
Lucas Test Timing — Tertiary alcohols react immediately (cloudiness), secondary in 5 minutes, primary don't react at room temperature. Mnemonic: Turbo, Slow, Parked (T-S-P for 3°-2°-1°).
Carbylamine Reaction Specificity — Only primary amines give isocyanide (foul smell) with CHCl₃ and KOH. Remember: "Primary Carbylamine" test—distinguishes 1° from 2° and 3° amines.
AUFBAU Principle Order — Orbitals fill: 1s 2s 2p 3s 3p 4s 3d 4p 5s 4d... Remember: (n+l) rule—lower (n+l) fills first; if equal, lower n fills first.
VSEPR Shape Memory — 2 pairs=linear, 3=trigonal planar, 4=tetrahedral, 5=trigonal bipyramidal, 6=octahedral. Lone pairs reduce angles: NH₃ (107°) < CH₄ (109.5°). "LP > BP repulsion."
Coordination Number Trick — Common CNs: 2 (linear), 4 (square planar/tetrahedral), 6 (octahedral). Remember: Ag⁺=2, Cu²⁺=4, Fe³⁺=6 as typical examples for each geometry.
d-Block Oxidation States — Manganese shows maximum oxidation states (+2 to +7) due to 3d⁵4s². Remember: "Mn is Maximum" for variable oxidation states in 3d series.
Biology
Tissue System Mnemonic — Three tissue systems in plants: Epidermal (protective), Ground (bulk/storage), Vascular (transport). "Every Good Vegetable" for E-G-V order.
Animal Classification Ladder — Phylum order: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata, Chordata. Mnemonic: "Please Come Play Near Aunt Anne's Mansion Every Christmas."
Heart Chamber Flow — Deoxygenated: Vena Cava → Right Atrium → Right Ventricle → Lungs. Oxygenated: Lungs → Left Atrium → Left Ventricle → Aorta. "RAP music" (Right Atrium to Pulmonary) vs "LAA music" (Left Atrium to Aorta).
Enzyme Suffix Rule — Enzymes typically end in -ase. Pepsin, trypsin, chymotrypsin are exceptions. Substrate name + ase: maltase (maltose), lactase (lactose), sucrase (sucrose).
Cell Cycle Phase Duration — Interphase (G1-S-G2) takes ~95% of cell cycle time; M phase only ~5%. "Interphase is Immense" helps remember it's the longest phase.
Biomolecule Bond Memory — Proteins: peptide bonds. Carbohydrates: glycosidic bonds. Lipids: ester bonds. Nucleic acids: phosphodiester bonds. "Pro-Pep, Carb-Gly, Lip-Est, Nuc-Phos" matches each type.
Gas Exchange Surface — Humans: alveoli (~300 million, 70-80 m² area). Remember: "Alveoli are Abundant" for massive surface area enabling efficient O₂-CO₂ exchange.