RRB Group D 2018 Previous Year GK Questions with Answers

The halogens are placed in Group 17 of the modern periodic table. This family has five members - fluorine, chlorine, bromine, iodine and astatine.

An alkene carries one carbon-to-carbon double bond, and that bond uses up two hydrogen atoms that a saturated chain would have held, so the formula drops from CnH2n+2 to CnH2n. Putting n equal to 2 gives C2H4, ethene, the simplest alkene; n equal to 3 gives C3H6, propene.

Alkanes are saturated hydrocarbons in which carbon atoms are joined only by single bonds, and such a chain carries the largest possible number of hydrogen atoms, given by CnH2n+2.

The element with atomic number 56 is barium, and its outermost electron enters the 6s orbital, so it sits in the s-block.

Relative atomic mass is measured against the carbon-12 atom, one-twelfth of whose mass is taken as the standard unit. That unit is the atomic mass unit, written u, and it is defined as exactly one-twelfth of the mass of one atom of carbon-12.

Melting of ice only changes the state of water from solid to liquid; no new substance is formed, so it is a physical change.

Ice melts at 0 degrees Celsius, and 0 degrees Celsius is 273 K on the Kelvin scale. To change Celsius into Kelvin, add 273 to the Celsius reading, so 0 + 273 gives 273 K; the melting point of ice is usually written as 273.15 K in exact work.

Mass by mass percentage of a solution is the mass of the solute divided by the mass of the whole solution, multiplied by 100.

The heat produced by a current is given by Joule's law of heating, H equals I squared into R into t. Here the current is 0.3 A, the resistance is 418 ohms and the time is 1 minute, which is 60 seconds.

A quantity that has both magnitude and direction is a vector, and momentum, which is the product of mass and velocity, is a vector because velocity has a direction.

Ammonium chloride is the salt of a strong acid, hydrochloric acid, and a weak base, ammonium hydroxide, so its aqueous solution is acidic and its pH is less than 7.

Adding water to an acid spreads the same number of hydrogen ions through a larger volume, so the number of hydrogen ions per unit volume falls, and that process is called dilution.

Birds and mammals are warm-blooded, which means they keep their body temperature nearly constant whatever the temperature outside, and a pigeon is a bird.

The weight of an object is the force with which the earth attracts it, so the force of gravity acting on an object is its weight.

Deposition is the direct change of a substance from the gaseous state to the solid state, without passing through the liquid state in between.

In Sanjay Leela Bhansali's Padmaavat he played the Delhi Sultan Alauddin Khalji, whose siege of Chittor in 1303 is the historical background of the story, which is drawn from the Padmavat of Malik Muhammad Jayasi.

Babur's memoir was written in Chagatai Turkish and was translated into Persian in Akbar's time by Abdur Rahim Khan-i-Khanan, one of the nine jewels of the court, so that the book could be read by the Persian speaking nobility of the empire.

Wheat is the leading rabi crop of India. It is sown in October and November, needs a cool season of about fifty to sixty centimetres of rainfall for growth and bright sunshine at the time of ripening, and is harvested in March and April.

An echo is the sound heard when a wave is reflected from a distant obstacle and comes back, so in the time measured the sound covers the distance to the cliff and then the same distance back again.

Plant tissues are first divided into meristematic tissue, whose cells keep dividing, and permanent tissue, whose cells have stopped dividing and have taken a fixed shape and job.