C-DAC, the organisation behind India's PARAM supercomputers, stands for:

The correct answer is A, Electronic Numerical Integrator and Computer. ENIAC was built to compute artillery firing tables and is remembered as the first general-purpose electronic digital computer; it used thousands of vacuum tubes and belongs to the first generation of computers. Option B is wrong because no part of the name contains the word calculator, which belongs instead to EDSAC, the Electronic Delay Storage Automatic Calculator. Option C is wrong because the letter C in ENIAC stands for Computer and not Compiler, and no early machine of this family carried the word network in its name. Option D is wrong because the first letter stands for Electronic and not Extended; the word Extended appears in EBCDIC, the Extended Binary Coded Decimal Interchange Code. Candidates should also keep EDVAC, the Electronic Discrete Variable Automatic Computer, and UNIVAC, the Universal Automatic Computer, separate from ENIAC.

The correct answer is B, 4. A bit is a single binary digit, zero or one; four bits together form a nibble, and two nibbles, that is eight bits, form a byte. The nibble is a convenient unit because one hexadecimal digit is written in exactly four bits, which is why Binary Coded Decimal also stores each decimal digit in four bits. Option A is wrong because two bits have no standard name in this ladder. Option C is wrong because eight bits make a byte, the unit in which file sizes are measured, and this is the commonest trap in the question. Option D is wrong because sixteen bits are usually described as a word on a sixteen-bit machine, not as a nibble. The ladder above the byte is the one to memorise: 1,024 bytes make a kilobyte, 1,024 kilobytes a megabyte and 1,024 megabytes a gigabyte.

The correct answer is A, American Standard Code for Information Interchange. ASCII assigns a number to every letter, digit and punctuation mark so that text can be stored and sent as binary; in its original form it is a seven-bit code and therefore represents 128 characters. Option B is wrong because the second word is Standard, not Series, and the code is for interchange between systems rather than anything internal. Option C is wrong because the first word is American, naming the standards body that issued it, and not Automatic. Option D is wrong because Advanced and Serial form no part of the name, although serial transmission is one way ASCII text travels. The code to contrast it with is EBCDIC, the Extended Binary Coded Decimal Interchange Code, an eight-bit code used on mainframe computers, while Unicode extends coverage to the scripts of the world, Devanagari among them.

The correct answer is C, Basic Input Output System. The BIOS is held in a read only memory chip on the motherboard; when the machine is switched on it tests the hardware through the power-on self test and then loads the operating system from the disc into main memory, a process called booting. Option A is wrong because the final word is System and not Software, and the BIOS handles both input and output rather than output alone. Option B is wrong because the first letter stands for Basic, not Binary, even though the chip of course stores binary code. Option D is wrong because the BIOS is not itself an operating system; it only starts the machine and hands control to the operating system, whose core is called the kernel. Because the BIOS sits permanently in a chip it is the standard textbook example of firmware, which is the term examiners pair with it.

The correct answer is B, SMTP, the Simple Mail Transfer Protocol, which carries a message from the sender's programme to the mail server and onward between servers. Option A is wrong because POP3, the Post Office Protocol version 3, works in the other direction: it downloads mail from the server to the user's computer, usually removing it from the server. Option C is wrong because FTP, the File Transfer Protocol, moves files between a client and a server and has nothing to do with mail delivery. Option D is wrong because SNMP, the Simple Network Management Protocol, is used to monitor and manage network devices such as routers and switches; its similarity to SMTP by one letter is exactly why it is offered here. The third mail protocol worth knowing is IMAP, the Internet Message Access Protocol, which reads mail while leaving it on the server.