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RRB ALP GK Questions 2026

General Science is the knowledge section of RRB ALP under CEN 01/2026. The CEN defines it as Physics, Chemistry and Life Sciences of Class 10 level in CBT-1, and CBT-2 Part A adds Basic Science and Engineering: units and measurements, mass, weight and density, work, power and energy, speed and velocity, heat and temperature, basic electricity, levers and simple machines, engineering drawing, occupational safety and health, environment education and IT literacy. The notes on this page are GK24's topic-wise GK notes for RRB ALP, written as short facts, formulas and tables so that a topic can be revised in one sitting. Physics notes cover motion, force, gravitation, work and energy, sound, light, electricity and magnetism; Chemistry notes cover matter, atoms and molecules, chemical reactions, acids, bases and salts, metals and non-metals, carbon compounds and the periodic table; Life Sciences notes cover the cell, life processes, control and coordination, reproduction, heredity, diseases and the environment. Topics that appear in both CBT-1 General Science and CBT-2 Basic Science and Engineering, such as units, energy, heat and electricity, are marked so that one reading serves two papers. Each note ends with the previous-year questions asked on it, and the quizzes on this site draw from the same topics, so a weak quiz score points back to the note to reread.

RRB ALP GK Questions with Answers

Q41.General ScienceEasy

Hooke's law states that within the elastic limit

  1. A.Stress is directly proportional to strain
  2. B.Stress is inversely proportional to strain
  3. C.Strain is independent of stress
  4. D.Stress is proportional to the square of the strain
Show answer
Correct answer: A. Stress is directly proportional to strain

Hooke found that so long as a body is not strained beyond its elastic limit, the restoring force per unit area rises in step with the fractional deformation, and the constant ratio of the two is called the modulus of elasticity.

Q42.General ScienceAsked in: CDS · CDS-I 2017, GKMedium

A photon of X-ray has energy of 1 keV. A photon of visible radiation has energy of 3 eV. In this context, which one of the following statements is not correct?

  1. A.The wavelength of X-ray photon is less than the wavelength of visible radiation photon.
  2. B.Both the photons have different energies.
  3. C.The speeds of both the photons in vacuum are different.
  4. D.The frequency of X-ray photon is higher than the frequency of visible radiation photon.
Show answer
Correct answer: C. The speeds of both the photons in vacuum are different.

This statement is wrong because every photon, whatever its energy, travels in vacuum at the same speed of light, about 3 × 10^8 metres per second.

Q43.General ScienceAsked in: CDS · CDS-II 2018, GKHard

When a convex lens produces a real image of an object, the minimum distance between the object and image is equal to

  1. A.the focal length of the convex lens
  2. B.twice the focal length of the convex lens
  3. C.four times the focal length of the convex lens
  4. D.one half of the focal length of the convex lens
Show answer
Correct answer: C. four times the focal length of the convex lens

The gap between an object and its real image is smallest when the object is placed at 2F, twice the focal length from the lens.

Q44.General ScienceMedium

Equal volumes of all gases, under the same conditions of temperature and pressure, contain an equal number of molecules. This statement is known as

  1. A.Avogadro's law
  2. B.Boyle's law
  3. C.Charles's law
  4. D.Dalton's law of partial pressures
Show answer
Correct answer: A. Avogadro's law

It is the reason one mole of every gas occupies the same 22.4 litres at standard temperature and pressure, and it allowed chemists to settle the formulae of gases such as hydrogen and oxygen as having two atoms each.

Q45.General ScienceHard

Carbon forms two oxides, carbon monoxide and carbon dioxide, in which twelve grams of carbon combines with sixteen grams and thirty two grams of oxygen respectively. This illustrates

  1. A.The law of conservation of mass
  2. B.The law of constant proportions
  3. C.The law of multiple proportions
  4. D.Avogadro's law
Show answer
Correct answer: C. The law of multiple proportions

When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other bear a simple whole number ratio, and here the oxygen masses of sixteen and thirty two grams for the same twelve grams of carbon are in the ratio…

Q47.General ScienceMedium

One unified atomic mass unit, written as u, is defined as

  1. A.The mass of one hydrogen atom
  2. B.One twelfth of the mass of one atom of carbon twelve
  3. C.One sixteenth of the mass of one atom of oxygen
  4. D.The mass of one electron
Show answer
Correct answer: B. One twelfth of the mass of one atom of carbon twelve

This standard was adopted so that the atomic masses of all elements could be compared on one relative scale, and on it hydrogen comes out as about 1 u, oxygen as 16 u and chlorine as 35.5 u. Option A is wrong because the hydrogen atom was the standard in…

Q48.General ScienceMedium

At standard temperature and pressure, the volume occupied by one mole of any gas is

  1. A.11.2 litres
  2. B.22.4 litres
  3. C.24.4 litres
  4. D.1 litre
Show answer
Correct answer: B. 22.4 litres

It follows from Avogadro's law: since equal volumes of all gases at the same temperature and pressure contain an equal number of molecules, one mole of hydrogen, of oxygen or of carbon dioxide all take up the same space at standard temperature and pressure, even though their masses are two…

Q49.General ScienceEasy

The number of particles present in one mole of any substance is

  1. A.6.022 into ten to the power twenty-three
  2. B.6.022 into ten to the power twenty-one
  3. C.3.011 into ten to the power twenty-three
  4. D.9.8 into ten to the power twenty-three
Show answer
Correct answer: A. 6.022 into ten to the power twenty-three

It is the number of atoms in twelve grams of carbon twelve, and it holds for atoms, molecules, ions or electrons alike, so one mole of water has that many water molecules and one mole of sodium has that many sodium atoms.

Q50.General ScienceAsked in: RRB ALP · 27 Nov 2024, Shift 2Medium

The formula unit mass of CaCl2 is:

  1. A.115u
  2. B.114u
  3. C.111u
  4. D.110u
Show answer
Correct answer: C. 111u

Calcium chloride is an ionic compound, so the sum of the atomic masses in its formula is called the formula unit mass rather than the molecular mass.

Q51.General ScienceAsked in: RRB ALP · 17 Aug 2018, Shift 2Easy

Atomic mass of Nitrogen is 14 and that of Hydrogen is 1. What will be the molecular mass of Ammonia?

  1. A.17
  2. B.18
  3. C.15
  4. D.16
Show answer
Correct answer: A. 17

The formula of ammonia is NH3, so its molecular mass is the atomic mass of one nitrogen atom added to the atomic masses of three hydrogen atoms, that is fourteen plus three times one, which equals seventeen unified atomic mass units; one mole of ammonia therefore weighs seventeen grams.

Q52.General ScienceMedium

The law which states that a pure chemical compound always contains the same elements combined in the same proportion by mass is known as

  1. A.The law of multiple proportions
  2. B.The law of constant proportions
  3. C.The law of conservation of mass
  4. D.The law of gaseous volumes
Show answer
Correct answer: B. The law of constant proportions

Water drawn from a river, from rain or made in a laboratory always has hydrogen and oxygen in the mass ratio of one to eight, and ammonia always has nitrogen and hydrogen in the ratio of fourteen to three.

Q53.General ScienceEasy

The law of conservation of mass in a chemical reaction was given by

  1. A.John Dalton
  2. B.Antoine Lavoisier
  3. C.Joseph Proust
  4. D.Amedeo Avogadro
Show answer
Correct answer: B. Antoine Lavoisier

The correct answer is B, Antoine Lavoisier, the French chemist who showed by careful weighing in closed vessels that the total mass of the products of a reaction is exactly equal to the total mass of the reactants, so that matter is neither created nor destroyed in a chemical change.

Q55.General ScienceHard

The expulsion of magnetic flux from the interior of a superconductor is known as

  1. A.The Hall effect
  2. B.The Meissner effect
  3. C.The Zeeman effect
  4. D.The Seebeck effect
Show answer
Correct answer: B. The Meissner effect

When a material becomes superconducting it pushes the magnetic field out of its interior and behaves as a perfect diamagnet, an effect reported by Meissner and Ochsenfeld in 1933; it is the reason a small magnet can be made to hover above a cooled superconductor, as in magnetic levitation demonstrations.

Q56.General ScienceMedium

Superconductivity was discovered in 1911 in mercury cooled to about 4.2 kelvin by

  1. A.Heike Kamerlingh Onnes
  2. B.Walther Meissner
  3. C.John Bardeen
  4. D.Georg Bednorz
Show answer
Correct answer: A. Heike Kamerlingh Onnes

The Dutch physicist Kamerlingh Onnes, who had already succeeded in liquefying helium, cooled mercury with it in 1911 and found that its electrical resistance disappeared completely below about 4.2 kelvin, the first observation of superconductivity.

Q57.General ScienceMedium

The property of laser light by which all its waves are in the same phase is called

  1. A.Monochromaticity
  2. B.Coherence
  3. C.Divergence
  4. D.Polarisation
Show answer
Correct answer: B. Coherence

Coherence means that the waves in the beam keep a constant phase relationship, so crest marches with crest; this is a direct result of stimulated emission, since each new photon is emitted in phase with the photon that caused it, and it is what makes holography and interference work with…

Q59.General ScienceEasy

The word LASER is an abbreviation for

  1. A.Light Absorption by Spontaneous Emission of Radiation
  2. B.Light Amplification by Stimulated Emission of Radiation
  3. C.Linear Amplification of Stored Energy by Radiation
  4. D.Light Alignment by Statistical Emission of Rays
Show answer
Correct answer: B. Light Amplification by Stimulated Emission of Radiation

The device works by stimulated emission, in which a photon passing an excited atom makes it fall to a lower level and emit a second photon identical in frequency, phase and direction, so one photon becomes two and the light is amplified.

Q60.General ScienceEasy

The minimum energy required to eject an electron from the surface of a metal is called its

  1. A.Work function
  2. B.Stopping potential
  3. C.Ionisation energy
  4. D.Binding energy
Show answer
Correct answer: A. Work function

The work function of a metal is the least energy needed to free an electron from its surface, and it is equal to Planck's constant multiplied by the threshold frequency of that metal; caesium and potassium have low work functions, which is why they respond to visible light.