RRB ALP 2018 Previous Year GK Questions with Answers

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.

The number of moles is the given mass divided by the molar mass, so 60 grams of helium divided by 4 grams per mole gives 15 moles.

A mole is a count, not a weight: one mole of any element holds 6.022 into 10 to the power 23 atoms, the Avogadro number, whatever the element is.

First find the throwing speed from the height: v squared equals u squared minus 2 g h gives u equal to the square root of 2 into 10 into 80, that is 40 metres per second.

By the work-energy theorem the work done by a force equals the change in kinetic energy, so the work here is half of 4 kilograms times 5 metres per second squared, that is 0.5 into 4 into 25, which gives 50 joules.

A convex mirror bulges towards the viewer and always gives a virtual, erect and diminished image, so whatever your distance from it, your reflection looks smaller than you.

Razia Sultan was the daughter of Iltutmish, and Iltutmish belonged to the Slave dynasty, also called the Mamluk dynasty or the Ilbari Turks.

The focal length of a mirror does not depend on the medium around it, so a convex mirror of focal length f in air keeps the focal length f inside the liquid.

The receptors that pick up taste are called gustatory receptors, and they sit inside the taste buds on the tongue.

Pitch is how shrill or how flat a sound seems to the ear, and it is decided by frequency, the number of vibrations per second measured in hertz.

The first equation of motion is written as v equals u plus a t, so it tells how the velocity of a body changes with time.

The Freedom Trail is a 2.5-mile red brick path laid out in Boston, Massachusetts, in 1951, linking sixteen sites connected with the American Revolution.

Green plants use sunlight trapped by chlorophyll to join carbon dioxide and water, and the balanced equation reads six molecules of carbon dioxide plus twelve of water giving one molecule of glucose, six of oxygen and six of water.

The pH is the negative logarithm of the hydrogen ion concentration, so each rise of one unit means the concentration has fallen to one tenth.

Vegetable oils contain unsaturated fatty acids with carbon-carbon double bonds, and when hydrogen is passed through the oil at about 60 degrees Celsius in the presence of finely divided nickel, the double bonds add hydrogen and become saturated, turning the liquid oil into semi-solid vanaspati.

An amphoteric oxide reacts with both acids and bases to give a salt and water. Aluminium oxide dissolves in hydrochloric acid to give aluminium chloride and in sodium hydroxide to give sodium aluminate, so it behaves as a base in one case and as an acid in the other.

Benzene has the formula C6H6 and a ring of six carbon atoms, each carrying one hydrogen. Count the sigma bonds first: six carbon-carbon bonds around the ring and six carbon-hydrogen bonds give twelve sigma bonds.

Ethylene, also called ethene, has the formula C2H4, and its two carbon atoms share two pairs of electrons, which is a carbon-carbon double bond made of one sigma and one pi bond; it is the simplest alkene.

In a double displacement reaction two compounds exchange their ions, so both reactants must be compounds. Here hydrogen and oxygen are elements combining to form a single product, water, which makes it a combination reaction and also a combustion and redox reaction, but certainly not a double displacement.

Johann Wolfgang Dobereiner, a German chemist, grouped elements of similar properties in sets of three that he called triads. His rule was that the atomic mass of the middle element is about the average of the other two.