RRB ALP GK Questions 2026

Abscisic acid is the one plant hormone in this list that slows growth instead of speeding it up, which is why it is often called the stress hormone of plants.

Testosterone is made by the Leydig cells of the testes and is the main male sex hormone.

White blood cells are usually about 8 to 20 micrometres across, larger than red cells but not in the range given here.

Gases move across the cell membrane by diffusion, the spread of particles from a region where they are more concentrated to a region where they are less concentrated.

Mendeleev arranged the elements by increasing atomic mass in 1869 and left blank spaces where his pattern demanded an element that was not yet known.

After discovering the electron in 1897, J. J. Thomson pictured the atom as a sphere of positive charge with negatively charged electrons stuck in it, a picture often compared to plums in a pudding or seeds in a watermelon.

Isotopes are atoms of the same element, so they have the same number of protons and therefore the same atomic number, but they carry different numbers of neutrons, which makes their mass numbers differ.

The modern periodic table has seven horizontal rows, called periods, and eighteen vertical columns, called groups.

John Newlands arranged the fifty-six elements known in 1866 in order of increasing atomic mass, beginning with hydrogen, the lightest, and ending with thorium, the fifty-sixth.

Henry Moseley showed in 1913, from the frequencies of the X-rays that elements emit, that the atomic number, the number of protons in the nucleus, is the more fundamental property of an element.

Electronegativity is the tendency of an atom to attract a shared pair of electrons towards itself. It increases from left to right across a period, as nuclear charge grows, and decreases down a group, as each new shell puts the outer electrons further from the nucleus.

The alkali metals are lithium, sodium, potassium, rubidium, caesium and francium. Each has a single electron in its outermost shell, loses it readily to form a positive ion, and therefore stands in group 1 of the modern periodic table.

The capacity of a shell is given by the formula 2n squared, where n is the number of the shell counted outward from the nucleus.

Most alpha particles passed straight through the foil, a few were deflected through small angles and about one in twenty thousand bounced back.

James Chadwick discovered the neutron in 1932 by bombarding beryllium with alpha particles and showing that the radiation produced consisted of neutral particles of nearly the same mass as the proton.

The Greek philosopher Democritus, working in the fifth century before the common era, argued that matter could be divided only up to a limit, and he called that smallest indivisible particle atomos, from which the word atom comes.

The resistance of a wire equals the resistivity of the material multiplied by the length and divided by the area of cross section.

It is the energy consumed by an appliance of one kilowatt working for one hour, and it equals three point six million joules.

The tangent drawn to a magnetic field line at any point gives the direction of the field at that point.

The fuse is a short piece of wire of low melting point placed in series in the live line, so that an excessive current melts it and breaks the circuit.