A physics plan for NDA

Physics is the single largest block in the General Knowledge part of the NDA General Ability Test (Paper II). The NDA & NA (II) 2026 notification gives the GK section's weightage as Physics 25%, History 20%, Geography 20%, Chemistry 15%, General Science 10% and Current Events 10%. With GK worth 400 marks, a 25% share means physics carries roughly 100 marks, more than any other GK area.

The good news is the style. NDA physics is mostly conceptual: what a law says, which unit measures what, why a device works, what happens in an everyday situation. There are some calculations, but they are one or two steps with round numbers, since calculators are not allowed. A candidate who understands Class 9–10 physics well and has read the relevant Class 11–12 chapters for depth can score heavily here.

What the syllabus covers

The official syllabus lists these areas under Physics. In plain terms:

• Matter and its properties: mass, weight, volume, density and specific gravity, Archimedes' principle, pressure and the barometer.
• Mechanics: motion, velocity and acceleration, Newton's laws, force and momentum, the parallelogram of forces, stability and equilibrium, gravitation, and elementary work, power and energy.
• Heat: effects of heat, measuring temperature and heat, change of state and latent heat, and the modes of heat transfer.
• Sound: sound waves and their properties, and simple musical instruments.
• Light: rectilinear propagation, reflection and refraction, spherical mirrors and lenses, and the human eye.
• Magnetism: natural and artificial magnets, properties of a magnet, and the Earth as a magnet.
• Electricity: static and current electricity, conductors and insulators, Ohm's law, simple circuits, the heating, lighting and magnetic effects of current, measurement of electrical power, primary and secondary cells, and uses of X-rays.
• How things work: the general principles behind everyday devices, such as the simple pendulum, pulleys, siphon, levers, balloon, pumps, hydrometer, pressure cooker, thermos flask, telescope, microscope, periscope, mariner's compass, lightning conductor and safety fuse. The list also includes a few older devices that rarely appear in textbooks now.

That last group deserves its own notebook page. Each device is one principle, and the questions are easy marks if you have written the principle down once.

How questions are asked

Statement-based questions deserve special care. They reward the student who knows the exact condition under which a law holds, for example that momentum is conserved only when no external force acts.

Formulas worth knowing cold

An eight-week plan

A study pattern that works: read the NCERT chapter (Class 9–10 first, then the matching Class 11–12 sections for depth), write one page of notes (laws, units, formulas and three everyday applications), solve 20–30 questions, and add every mistake to an error log. At the end of each week, take a mixed quiz on everything done so far.

Worked NDA-style MCQs

Q1. A body of mass 2 kg moves at 3 m/s. Its kinetic energy is:
(a) 6 J (b) 3 J (c) 18 J (d) 9 J

KE = ½ × 2 × 3² = 9 J. Option (a) is its momentum in kg m/s, not energy. Answer: (d).

Q2. Two 6 Ω resistors are connected in parallel. The equivalent resistance is:
(a) 12 Ω (b) 6 Ω (c) 3 Ω (d) 1.5 Ω

For two equal resistors in parallel, the result is half of one: 6/2 = 3 Ω. Answer: (c).

Q3. Food cooks faster in a pressure cooker because:
(a) the boiling point of water rises with pressure (b) heat is trapped by the lid (c) steam conducts heat better than water (d) pressure lowers the boiling point

The higher pressure inside raises water's boiling point above 100 °C, so the food is cooked at a higher temperature. Answer: (a).

Q4. A short-sighted (myopic) person needs spectacles with:
(a) a convex lens (b) a concave lens (c) a cylindrical lens (d) a bifocal lens

In myopia the image forms in front of the retina; a diverging (concave) lens moves it back. Answer: (b).

Q5. Sound travels fastest in:
(a) air (b) water (c) steel (d) vacuum

Sound travels fastest in solids, slower in liquids, slower still in gases, and not at all in a vacuum. Answer: (c).

Q6. An object weighs 60 N on Earth. Taking the Moon's gravity as one-sixth of Earth's, its weight on the Moon is about:
(a) 10 N (b) 60 N (c) 360 N (d) 0

Mass stays the same; weight = mg falls to one-sixth. Answer: (a).

Common mistakes

• Studying only numericals and missing the conceptual and device questions, which make up much of the section.
• Confusing related units: joule (energy) and watt (power), coulomb (charge) and ampere (current), kWh (energy) and kW (power).
• Mixing mass and weight. Mass is constant; weight changes with g.
• Ignoring conditions. "Momentum is conserved" is true only without an external force; statement questions hinge on such conditions.
• Leaving the devices list to the end. It is the cheapest scoring material in the syllabus.

Practice set

1. The SI unit of electric charge is: (a) ampere (b) volt (c) coulomb (d) ohm
2. A hydrometer works on the principle of: (a) Pascal's law (b) Archimedes' principle (c) Bernoulli's principle (d) Boyle's law
3. A thermos flask reduces heat transfer by: (a) conduction only (b) radiation only (c) conduction and convection only (d) conduction, convection and radiation
4. A good fuse wire should have: (a) a low melting point (b) a high melting point (c) zero resistance (d) high conductivity and a high melting point
5. A periscope works by: (a) refraction through lenses (b) diffraction (c) total internal reflection in fibres only (d) reflection from two plane mirrors
6. A convex lens has a focal length of 50 cm. Its power is: (a) +2 D (b) +0.5 D (c) −2 D (d) +50 D
7. A 5 V battery drives current through a 10 Ω resistor. The current is: (a) 2 A (b) 50 A (c) 0.5 A (d) 5 A
8. Which of these is a vector quantity? (a) speed (b) momentum (c) work (d) energy

Answers:

1. (c). One coulomb is the charge carried by one ampere in one second.
2. (b). A floating body displaces liquid equal to its own weight, so it sinks deeper in less dense liquids.
3. (d). The vacuum stops conduction and convection; the silvered walls reduce radiation.
4. (a). It must melt quickly when the current exceeds the safe limit.
5. (d). Two plane mirrors (or prisms) at 45° turn the light twice.
6. (a). P = 1/f = 1/0.5 m = +2 D; a convex lens has positive power.
7. (c). I = V/R = 5/10.
8. (b). Momentum has direction; the others are scalars.

What to do next

• Download the current NDA notification and copy the physics syllabus onto the first page of your notebook.
• Start with units, measurement and motion basics, then follow the eight-week table in order.
• Give electricity extra time; it has the most one-step numericals. See electricity for NDA.
• In week 8, use the physics revision sheet for the final pass.