ANM GNM Physical Science Study Notes
Master Physics and Chemistry for your WBJEEB entrance exam. Summary of core concepts, formulas, and periodic table trends compiled by expert educators.
Physical Science Syllabus Structure
Physical Science carries a weightage of 20 marks. There are 15 questions in Category-1 (1 mark each, -0.25 negative marking) and 5 questions in Category-2 (2 marks each, no negative marking).
1. Light (Optics)
Laws of reflection/refraction, lens formulas, lens power (Dioptres), dispersion of light, critical angle, and total internal reflection.
2. Current Electricity
Ohm's Law (V=IR), electrical resistance, combination of resistors (series & parallel), electrical energy and heating effects of current.
3. Atomic Structure & Bonding
Isotopes, Isobars, Isotones. Chemical bonding (covalent vs electrovalent/ionic), octet rule, and electronic configurations.
4. Periodic Table & Properties
Mendeleev's vs Modern Periodic Table. Periodic properties and trends (atomic radius, electronegativity, ionization energy).
Light, Lenses & Wave Optics
Key Points:
- Refraction Index (μ): Speed of light in vacuum / Speed of light in medium (c / v).
- Critical Angle (θc): The angle of incidence in a denser medium for which the angle of refraction in the rarer medium is 90°. Formulated as: sin(θc) = 1/μ.
- Convex Lens: Converging lens. Used to correct Hypermetropia (farsightedness).
- Concave Lens: Diverging lens. Used to correct Myopia (nearsightedness).
- Power of Lens (P): P = 1 / f (focal length in meters). Unit is Dioptre (D). A convex lens has positive power, concave has negative power.
Electricity & Electronics
Formulas & Laws:
| Law / Concept | Formula | Key Definition / Meaning |
|---|---|---|
| Ohm\'s Law | V = I × R | Current (I) is directly proportional to potential difference (V) at constant temperature. |
| Resistors in Series | Rs = R₁ + R₂ + R₃ | Current remains the same; total resistance increases. |
| Resistors in Parallel | 1/Rp = 1/R₁ + 1/R₂ + 1/R₃ | Voltage remains the same; total resistance decreases. |
| Joule\'s Law of Heating | H = I² × R × t | Heat produced (H) is proportional to the square of current, resistance, and time. |
| Electric Power | P = V × I = I²R = V²/R | Rate at which electrical energy is consumed. Unit: Watt (W). |
Chemistry — Atomic Structure & Periodic Trends
⚛️ Atomic Definitions
Isotopes: Same atomic number (Z), different mass number (A). (e.g., ¹H, ²H, ³H).
Isobars: Same mass number (A), different atomic number (Z). (e.g., ⁴⁰Ar, ⁴⁰Ca).
Isotones: Same number of neutrons (A - Z). (e.g., ¹⁴C, ¹⁵N, ¹⁶O have 8 neutrons).
📈 Periodic Table Trends
Left to Right in a Period: Atomic size decreases, ionization energy increases, electronegativity increases.
Top to Bottom in a Group: Atomic size increases, ionization energy decreases, electronegativity decreases.
Note: Fluorine (F) is the most electronegative element. Helium (He) has the highest ionization energy.
Physical Science FAQs
Score 15+ in Physical Science
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