RRB Group D GK Questions 2026

The retina is the innermost coat of the eyeball and it carries the photoreceptor cells, the rods and the cones, which convert light into nerve impulses that the optic nerve carries to the brain; the image formed on the retina is real and inverted, and the brain interprets it as…

The three semicircular canals of the inner ear are set at right angles to one another and are filled with fluid; movement of the head moves the fluid, which stimulates the receptors and tells the brain about the position and motion of the head, so that balance or equilibrium is…

The stapes, also called the stirrup because of its shape, lies in the middle ear and is the smallest bone in the human body; it passes the vibration received from the eardrum on to the oval window of the inner ear.

Gustatory receptors are the receptors of taste, and they lie in the taste buds of the tongue, which sit mostly on small projections called papillae; they are stimulated by chemicals dissolved in saliva and send impulses to the brain.

The iris is the coloured ring in front of the lens, formed by the front part of the choroid, and the muscles in it widen or narrow the pupil so that the right amount of light reaches the retina; in dim light the pupil opens wide and in bright light…

Niranjan Mukundan won the bronze in the Men’s 200m Individual Medley SM7 event at the Asian Para Games 2026 on 20 October 2026, and the individual medley is a swimming race in which one competitor covers the distance in four different strokes.

Hokato Hotozhe Sema took the bronze there on 20 October 2026, and the Prime Minister noted that the throw improved on what he had produced at the previous edition of the Games, calling it a sign of passion and dedication.

Preeti Pal finished second in the Women’s 200m T35 sprint at the Asian Para Games 2026 on 20 October 2026, and the Prime Minister described her as a fine example of perseverance and dedication while hoping she would carry the momentum into her remaining events.

Pradeep Kumar secured the bronze in the Men’s Discus Throw F43/F44/F62/F64 event at the Asian Para Games 2026 with the best throw of his own career, and the Prime Minister praised his commitment to pushing his own limits.

Devender Kumar took the gold, Rakesh the silver and Pradeep Kumar the bronze in the Men’s Discus Throw F43/F44/F62/F64 at the Asian Para Games 2026 on 20 October 2026, which accounts for every medal the event had to give.

He won the gold medal in the Men’s Discus Throw F43/F44/F62/F64 event at the Asian Para Games 2026 on 20 October 2026, and the Prime Minister described the throw as excellent and the victory as a celebration of the way Indian para sport is growing.

When natural gas or heavy oil burns with too little air, the carbon cannot all turn into carbon dioxide and separates as a very fine black soot, which is collected as carbon black.

Hydrated oxalic acid has a molar mass of 126 and is a dibasic acid, so its equivalent weight is 126 ÷ 2 = 63.

Iodine exists as diatomic molecules, I₂, in which two iodine atoms share a pair of electrons; so its atomicity is two, not one.

Here water only combines with calcium sulphate hemihydrate to form gypsum; no gas is given off and the paste simply sets hard.

Most carbon compounds are poor conductors of electricity, because their atoms are joined by covalent bonds and they do not form ions or free electrons that could carry a current.

Goldsmiths dip gold and silver ornaments in dilute nitric acid to dissolve the dirt, oxide layers and traces of base metals stuck to them, which brings back their shine.

Both statements are true, and the second explains the first: infrared waves are called heat waves because water molecules, present in most materials, absorb them readily and heat up.

Heat is energy in transit: it flows from a hotter body to a colder one only because their temperatures differ, and stops when they reach the same temperature.

The SI unit of inductance is the henry, symbol H, named after the American scientist Joseph Henry. Inductance measures how strongly a coil opposes a change in the current through it by producing an induced emf.