RRB JE GK Questions 2026

In the SI system the prefix femto, written f, stands for 10 raised to minus 15. The name comes from the Danish and Norwegian word femten, meaning fifteen.

Potassium permanganate is a neutral compound, so the oxidation numbers of all its atoms must add up to zero. Potassium, an alkali metal, is always +1, and each of the four oxygen atoms is -2, giving the oxygens a total of -8.

The Sabarmati rises in the Aravalli Range in the Udaipur district of Rajasthan, then flows south-west across Gujarat and empties into the Gulf of Khambhat in the Arabian Sea after a course of about 371 km.

Coulomb friction, also called dry friction, is the resistance that acts when two solid surfaces touch each other with no lubricant between them.

In electroplating the article to be coated is made the cathode, the plating metal serves as the anode, and both are dipped in an electrolyte containing a salt of that metal.

Balance is controlled by the inner ear, which holds the vestibular apparatus alongside the organ of hearing. It is made of three semicircular canals set at right angles to one another and two small sacs, the utricle and the saccule.

The speed of any wave is its frequency multiplied by its wavelength, so here 200 Hz times 2 m gives 400 metres per second.

HTTP, the HyperText Transfer Protocol, is the application-layer protocol a browser uses to ask a web server for a page and to receive the HTML, images and scripts that make it up.

HTML has no separate checkbox element at all. Every simple form control is written with the single input tag, and the type attribute decides what the browser draws, whether that is text, password, radio, checkbox, submit, file or hidden.

A concave lens, also called a diverging lens, spreads out the rays that fall on it and so can never bring them to a real focus.

Wetting is decided by a contest between two forces: cohesion, the attraction among the molecules of the liquid itself, and adhesion, the attraction between the liquid and the solid surface.

PPP is a data-link layer protocol that carries data directly between two nodes over a single link, such as a telephone line, a leased line or a serial cable.

Most renewable sources depend on the weather, so the power they give is intermittent rather than steady. Solar panels make nothing at night and little under thick cloud, wind turbines stop when the wind drops, and hydropower falls away in a weak monsoon.

Each hexadecimal digit stands for exactly four binary digits, so a two-digit hex number becomes an eight-bit binary number. Here C is 12 in decimal, which is 1100 in binary, and 6 is 0110.

The atomic number of an element is by definition the number of protons in its nucleus, so an atomic number of 11 means 11 protons.

Flash memory, ROM and a hard drive all keep their contents after the power is switched off, and that is exactly what non-volatile means.

Reduce the parallel pair first: 20 into 30 divided by 50 gives 12 ohms. Adding the 8 ohm resistor in series makes the circuit resistance 20 ohms, so the battery drives 12 volts divided by 20 ohms, that is 0.6 ampere, through the whole circuit.

In a class 3 lever the effort is applied between the fulcrum and the load, so the effort always sits nearer the fulcrum and its arm is the shorter of the two.

For resistors in parallel the reciprocals add, so one over R equals one over 20 plus one over 20, which is 2 over 20, and R comes out as 10 ohms.

The velocity ratio of a pulley system is the distance moved by the effort divided by the distance moved by the load, so it is 12 divided by 3, that is 4.