IBPS GK Questions 2026

The address bus carries only the address of the memory location or the input-output port that the processor wants to use, and that address always travels outwards from the processor to memory, never back; a bus that carries signals in one direction only is unidirectional.

In 1945 John von Neumann described a design in which a computer's instructions and its data are both held in the same memory in the same binary form, so that the machine can be given a new task simply by loading a new program instead of being rewired.

The program counter, sometimes called the instruction pointer, always holds the memory address of the next instruction the processor will fetch, and it is incremented automatically as each instruction is taken up so that execution moves forward in order; a jump or branch instruction works simply by loading a new…

The ALU is the part of the processor that actually does the work on data: addition, subtraction, multiplication and division on the arithmetic side, and comparison along with the logical operations AND, OR and NOT on the logic side.

Cache is a small quantity of very fast static RAM placed between the processor and main memory to hold the instructions and data most likely to be needed next, and of the options given it has the shortest access time; only the registers inside the processor itself are faster.

Read Only Memory is the permanent or non-volatile memory of a computer: its contents are written once and survive when the power is switched off, which is why the BIOS firmware that starts the machine and runs the power-on self-test is stored in it.

A byte is made up of eight bits, so half a byte is four bits, and four bits together are called a nibble.

A microprocessor is named after the width of its data bus, that is, the number of bits it can carry in and out in a single operation.

TIFRAC, the Tata Institute of Fundamental Research Automatic Calculator, was the first computer designed and built within India; it was commissioned in 1960 and Jawaharlal Nehru gave it that name.

In his report on the EDVAC design in 1945 John von Neumann set out a computer in which a single memory holds both the program and the data it works on, with a control unit, an arithmetic and logic unit and input and output; that layout is still called the…

Herman Hollerith built an electric tabulating machine that read holes punched in cards, and it cut the time needed to process the United States census of 1890 from years to months.

In 1936 the British mathematician Alan Turing described an abstract machine, now called the Turing machine, that defines what it means for a problem to be computable, and in 1950 he proposed the Turing test, by which a machine is judged intelligent if its answers cannot be told from a…

Intel released the 4004 in 1971, putting a complete central processing unit on a single chip for the first time and beginning the fourth generation of computers along with the age of the personal computer.

The Scottish mathematician John Napier published his work on logarithms in 1614, which turned multiplication into addition, and he then devised a set of numbered rods, Napier’s bones, with which products could be read off mechanically.

ENIAC, the Electronic Numerical Integrator and Computer, was completed in 1946 at the University of Pennsylvania by J. Presper Eckert and John Mauchly and used some eighteen thousand vacuum tubes; it was a first generation machine, filled a large room and consumed a great deal of power.

Ada Lovelace, the daughter of Lord Byron, worked with Charles Babbage on the Analytical Engine, and the notes she published in 1843 include a step by step sequence for computing Bernoulli numbers on it, which is recognised as the first computer program; a programming language, Ada, is named after her.

The French mathematician Blaise Pascal built the Pascaline in 1642 to help his father with tax calculations; it worked with toothed wheels and could add and subtract, and the programming language Pascal is named in his honour.

Babbage designed the Difference Engine in 1822 and then the Analytical Engine, a general purpose mechanical computer with a store for numbers, a mill for arithmetic, punched card input and printed output, which is the plan of a modern computer drawn a century before one could be built; for that…

The IBM System/360, announced in 1964, was built around integrated circuits, and the integrated circuit is exactly what defines the third generation of computers; the series is also remembered for introducing a single compatible family of machines of different sizes.

The generations of computers are named for the switching device they use, and the second generation, running from the late 1950s into the early 1960s, replaced the bulky vacuum tube with the transistor, which had been invented at Bell Laboratories in 1947.