RRB Group D GK Questions 2026

Mitochondria are membrane-bound organelles, and only eukaryotic cells have membrane-bound organelles. Prokaryotes such as bacteria and cyanobacteria have no true nucleus and no membrane-bound organelles; their DNA lies in a region called the nucleoid, and they carry out respiration on their plasma membrane.

Only this split of boron-10 and boron-11 gives an average atomic mass of 10.81. The relative atomic mass of an element is the average of its isotopes' masses, each weighted by how common it is.

Inside a long current-carrying solenoid the magnetic field has the same strength and direction at every point, shown by parallel, evenly spaced field lines.

A work done that is fixed by the starting and ending speeds alone is exactly what the work-energy theorem states: W(net) = ½mv² − ½mu².

The longer wire's resistance works out to 2.88 times that of the shorter one, which is 188% more. Resistance is R = ρL/A, where ρ is the resistivity of the material.

Of the three forms of carbon, only fullerenes are made of closed, hollow, cage-like molecules. The best-known fullerene is buckminsterfullerene, C60, a hollow sphere of 60 carbon atoms arranged in 20 hexagons and 12 pentagons, shaped like a football.

A simple periscope has two plane mirrors, and light reaches the eye only by bouncing off them. In a simple periscope, two plane mirrors are fixed parallel to each other at the two bends of a long tube, each tilted at 45° to its length.

A mixture of carbon monoxide and hydrogen is called synthesis gas, or syngas, because it is the starting material for making methanol and many other compounds.

This is sodium stearate, the sodium salt of a long-chain fatty acid, which makes it a soap and not a synthetic detergent.

This statement is false: water is a strongly polar molecule. In a water molecule the oxygen atom is much more electronegative than hydrogen, so it pulls the shared electrons towards itself and carries a partial negative charge, while the two hydrogens carry partial positive charges.

Argon has atomic number 18, and a neutral atom has as many electrons as protons, so it has 18 electrons.

X-rays have wavelengths of roughly 0.01 nm to 10 nm, so 1 nm sits right inside the X-ray band. The electromagnetic spectrum runs, from the shortest wavelength to the longest, as gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves and radio waves.

Meiosis makes gametes that differ from one another, and fertilization joins a gamete from each of two parents, so every offspring gets a new mix of genes.

Work is W = F × d × cos θ, and when the angle θ between force and displacement is 90°, cos 90° = 0, so the work done is zero.

As an object comes in from far away towards C, its real, inverted image moves out from the focus towards C, and the two meet at C. For a concave mirror, an object at infinity forms its image at the focus F, and an object at the centre of curvature…

To just complete a vertical circle, a bob on a string needs a speed of at least √(5gL) at the lowest point, and √(5 × 10 × 0.5) = √25 = 5 m/s. A string can only pull, never push.

The bonus was approved on the strength of the railways' performance in 2025-26, and the government cited a record freight loading of 1,670 million tonnes for that year together with a passenger count of nearly 7.41 billion.

That is the amount the Union Cabinet approved for paying a bonus of 78 days' wages to railway employees, and it is spread across 11,40,770 employees.

The Union Cabinet cleared a Productivity Linked Bonus equal to 78 days' wages for railway employees, and this is the figure every other number in the decision hangs on: the total sanctioned amount, the per-employee ceiling and the count of employees covered are all tied to the same 78 days.

A diode does not obey Ohm's law: the current through it is not proportional to the voltage across it. An ohmic conductor gives a straight-line graph of current against voltage, so its resistance stays constant at a fixed temperature.