Static general knowledge makes up about 90% of Part B of the NDA General Ability Test, about 360 of its 400 marks. The NDA & NA (II) 2026 notice divides it into five sections: Physics (about 25%), Chemistry (about 15%), General Science (about 10%), History, Freedom Movement etc. (about 20%) and Geography (about 20%). Half of Part B is science. Physics covers matter, motion, gravitation, heat, sound, light, magnetism, electricity and the working of everyday devices such as the siphon, pressure cooker, periscope and safety fuse. Chemistry covers changes of matter, elements and compounds, common gases, acids, bases and salts, carbon, fertilizers and the materials used to make soap, glass, cement and gunpowder. General Science covers cells, the human body, diseases, diet, the solar system and eminent scientists. Section D spans Indian history and culture, the freedom movement, the Constitution, Five Year Plans, Panchayati Raj and world history from the Renaissance to the Russian Revolution. Geography covers the Earth, rocks, oceans, the atmosphere and climate, and India's resources, industries, ports and trade. This page holds GK24's topic-wise GK notes for NDA, in English and Hindi, written as short facts and tables. Read a topic, then solve its quiz and previous-year questions on this site.
The focal length of a concave lens is 0.5 m. The power of the lens is
Power is the reciprocal of focal length in metres, and a concave lens has a negative focal length. The power of a lens is P = 1/f, with f in metres, and its unit is the dioptre (D).
Read the full explanation →A pendulum of length L oscillates with an angular amplitude of θ = 60° and time period T. Let T₀ = 2π√(L/g) be the time period for small angle of oscillations, where g is the acceleration due to gravity. If air resistance is negligibly small and the string remains straight, then which one of the following is correct?
The formula T₀ = 2π√(L/g) holds only for small swings; at large amplitudes the period grows.
Read the full explanation →A bicycle racing track is a level circular road of radius 10 m. Three cyclists P, Q and R with identical cycles are cycling on the track with speeds 2 m/s, 3 m/s and 5 m/s respectively. If the coefficient of friction between the tyres and the road is 0.1, then which cyclist will slip? (Take g = 10 m/s²)
On a level curve, friction alone supplies the centripetal force, so a cyclist slips when the needed force exceeds the maximum friction.
Read the full explanation →Which one of the following chemical reactions is not feasible?
Copper is less reactive than lead, so it cannot push lead out of its compound. In a displacement reaction, a more reactive metal takes the place of a less reactive metal in its salt solution.
Read the full explanation →Which of the following carbon allotropes is/are good conductor(s) of electricity? 1. Diamond 2. Graphite 3. Fullerene Select the correct answer using the code given below :
Graphite has free electrons that can move through it, so it conducts electricity; diamond and fullerene do not conduct well.
Read the full explanation →At the time of short-circuit, the current in the circuit:
In a short circuit the live and neutral wires touch, the resistance of the path falls almost to zero, and the current shoots up.
Read the full explanation →Which types of vegetation will you find on the way as you travel from Bikaner to Konark by road by shortest distance ?
The route runs from the dry west to the wet east coast, so the vegetation changes as rainfall rises. Bikaner lies in the Thar Desert of western Rajasthan, where rainfall is below about 25 cm and only desert plants such as khejri and cactus grow.
Read the full explanation →A leaf was plucked from a plant on a sunny day and kept for 2 minutes in boiling water. It was subsequently immersed in boiling alcohol and treated with iodine solution. What will be the final colour of the leaf after the test?
A leaf from a sunny day is full of starch made by photosynthesis, and iodine turns starch blue-black. This is the standard school test for starch in a leaf.
Read the full explanation →Sonic boom is produced when a source of sound travels at a speed :
A body moving faster than sound outruns its own sound waves, which pile up into a shock wave heard on the ground as a sonic boom.
Read the full explanation →Xylem in the plants are responsible for the transport of:
Xylem carries water along with the minerals dissolved in it from the roots up to the stem and leaves. Plants have two kinds of conducting tissue.
Read the full explanation →Identify the Mineral on the basis of the following characteristics relating to it : I. It is usually a greenish crystal. II. It is often found in basaltic rocks. III. Magnesium, iron and silica are its major elements. Select the answer using the code given below :
Olivine is a silicate of magnesium and iron that forms greenish crystals and is common in basalt. Olivine takes its name from its olive-green colour.
Read the full explanation →The antibiotic penicillin can kill invading bacteria without harming human cells because it targets bacterial :
Bacteria have a cell wall and human cells do not, so a drug that attacks the cell wall harms only the bacteria.
Read the full explanation →Polynucleotide chain of DNA contains
Each nucleotide of DNA is made of these three parts, and many nucleotides joined together form the polynucleotide chain. In a DNA strand, the sugar of one nucleotide is linked to the phosphate of the next by a phosphodiester bond, making a sugar-phosphate backbone.
Read the full explanation →Which one of the following islands is the largest?
With an area of about 7.86 lakh sq km, New Guinea is the world's second-largest island, after Greenland. New Guinea lies just north of Australia and is shared by two countries: its western half belongs to Indonesia and its eastern half is the mainland of Papua New Guinea.
Read the full explanation →Which one of the following elements is essential for the formation of chlorophyll in green plants?
A magnesium atom sits at the centre of every chlorophyll molecule, so a plant cannot make chlorophyll without it. Chlorophyll is built around a ring-shaped structure called a porphyrin, with a single magnesium ion held at its centre.
Read the full explanation →Two reactants in a flask at room temperature are producing bubbles of a gas that turn limewater milky. The reactants could be
A carbonate reacts with an acid at room temperature to give carbon dioxide, and only carbon dioxide turns limewater milky.
Read the full explanation →What is the effect of pressure of a human body on sand ?
The body's weight stays the same, but standing puts it on the small area of the feet, so the pressure is greater.
Read the full explanation →What is the correct sequence of resistivity of silver, nichrome and glass at room temperature ?
Silver is the best conductor, nichrome is an alloy with high resistivity, and glass is an insulator with enormous resistivity.
Read the full explanation →A sprinter feels cramps and pain in the thigh muscles after a run. This is due to accumulation of
During a hard sprint the muscles run short of oxygen and switch to anaerobic respiration, which leaves lactic acid behind.
Read the full explanation →If the Moon is brought closer to the Earth such that its distance from the Earth becomes half of the original distance, then the gravitational force of attraction between the Earth and the Moon would :
Gravitational force varies inversely as the square of the distance, so halving the distance makes the force 2 × 2 = 4 times larger.
Read the full explanation →