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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

Q61.General ScienceMedium

The maximum kinetic energy of the photoelectrons emitted from a metal surface depends on

  1. A.The intensity of the incident light
  2. B.The frequency of the incident light
  3. C.The area of the illuminated surface
  4. D.The time for which light falls
Show answer
Correct answer: B. The frequency of the incident light

By Einstein's photoelectric equation, the photon gives energy equal to Planck's constant times the frequency, part of which is spent as the work function, so the maximum kinetic energy left with the electron rises with frequency and is independent of how bright the light is.

Q62.General ScienceMedium

Albert Einstein was awarded the Nobel Prize in Physics for 1921 mainly for

  1. A.The special theory of relativity
  2. B.The general theory of relativity
  3. C.His explanation of the photoelectric effect
  4. D.The discovery of the photon rest mass
Show answer
Correct answer: C. His explanation of the photoelectric effect

The citation for the prize refers to his services to theoretical physics and especially to his discovery of the law of the photoelectric effect, the equation in which the energy of a photon equals the work function plus the maximum kinetic energy of the emitted electron.

Q63.General ScienceMedium

The photoelectric effect was first observed by which scientist?

  1. A.Albert Einstein
  2. B.Heinrich Hertz
  3. C.Max Planck
  4. D.Robert Millikan
Show answer
Correct answer: B. Heinrich Hertz

In 1887, while studying the sparks produced across a gap between two electrodes, Hertz noticed that the spark passed more easily when ultraviolet light fell on the electrodes, which was the first observation of the photoelectric effect; Hallwachs and Lenard then studied it systematically.

Q71.General ScienceMedium

The total pressure of a mixture of two non-reacting gases equals the sum of their individual pressures. This is

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

The law states that for a mixture of gases that do not react, the total pressure is the sum of the partial pressures each gas would exert if it alone occupied the whole volume at the same temperature.

Q72.General ScienceHard

The root mean square speed of the molecules of an ideal gas is given by the square root of

  1. A.RT divided by M
  2. B.2RT divided by M
  3. C.3RT divided by M
  4. D.8RT divided by pi M
Show answer
Correct answer: C. 3RT divided by M

The root mean square speed follows from the kinetic gas equation and equals the square root of three RT divided by the molar mass, or equally the square root of three times the Boltzmann constant times the temperature divided by the mass of one molecule.

Q73.General ScienceHard

Which of the following is NOT a postulate of the kinetic theory of gases?

  1. A.Gas molecules are in constant random motion
  2. B.Collisions between gas molecules are perfectly elastic
  3. C.Gas molecules attract one another strongly at all times
  4. D.The volume of the molecules is negligible compared with the volume of the container
Show answer
Correct answer: C. Gas molecules attract one another strongly at all times

The kinetic theory of an ideal gas assumes exactly the opposite: that there are no forces of attraction or repulsion between molecules except during the brief moment of a collision.

Q74.General ScienceAsked in: RRB JE · 26 May 2019, Shift 3Easy

On increasing the temperature of solids, the kinetic energy of the particles ________.

  1. A.First increases and then decreases
  2. B.Is constant
  3. C.Increases
  4. D.Decreases
Show answer
Correct answer: C. Increases

Temperature is a measure of the average kinetic energy of the particles of a substance, in a solid as in a gas: in a solid the particles are held in fixed positions but vibrate about them, and heating makes the vibrations faster and wider, so the average kinetic energy rises…

Q76.General ScienceMedium

According to Graham's law, the rate of diffusion of a gas is inversely proportional to the

  1. A.Square of its molar mass
  2. B.Square root of its molar mass
  3. C.Cube root of its molar mass
  4. D.Absolute temperature
Show answer
Correct answer: B. Square root of its molar mass

Graham's law of diffusion states that at the same temperature and pressure the rate at which a gas diffuses is inversely proportional to the square root of its density, and therefore of its molar mass.

Q77.General ScienceMedium

The volume occupied by one mole of an ideal gas at 273.15 K and one atmosphere pressure is about

  1. A.11.2 litres
  2. B.22.4 litres
  3. C.44.8 litres
  4. D.1 litre
Show answer
Correct answer: B. 22.4 litres

Substituting one mole, 273.15 kelvin and one atmosphere in the ideal gas equation gives a volume of 22.4 litres, the molar volume at standard temperature and pressure, and this is the figure used in mole calculations; with the modern standard pressure of one bar the value works out to about…

Q79.General ScienceEasy

Absolute zero of temperature is equal to

  1. A.0 degrees Celsius
  2. B.-100 degrees Celsius
  3. C.-273.15 degrees Celsius
  4. D.-373.15 degrees Celsius
Show answer
Correct answer: C. -273.15 degrees Celsius

Extending the straight line of Charles's law backwards shows that the volume of an ideal gas would become zero at minus 273.15 degrees Celsius, and this point is taken as the zero of the kelvin or absolute scale, at which molecular motion carries its least possible energy.

Q80.General ScienceEasy

A hot air balloon rises because warm air

  1. A.Becomes denser than the surrounding air
  2. B.Expands and becomes less dense than the surrounding air
  3. C.Loses its mass on heating
  4. D.Has a lower specific heat than cold air
Show answer
Correct answer: B. Expands and becomes less dense than the surrounding air

By Charles's law the volume of a fixed mass of gas at constant pressure is proportional to its absolute temperature, so heating the air inside the envelope makes it expand; some of it escapes from the open mouth, the mass of air left inside falls, its density becomes lower than…