13 questionswith explanationsfor RSSB CET Graduation Level
Which part of the CPU carries out calculations such as addition and comparisons such as 'greater than'?
Answer: (1) Arithmetic Logic Unit (ALU)
Explanation
The ALU performs arithmetic operations (addition, subtraction etc.) and logical operations (comparisons); the Control Unit directs the flow of instructions.
Which of the following devices works both as an input device and as an output device?
Answer: (3) Touch screen
Explanation
A touch screen displays output and also accepts input through touch; a scanner and light pen are input devices and a plotter is an output device.
The binary number 1101 is equal to which decimal number?
Answer: (4) 13
Explanation
1101 in binary = 1×8 + 1×4 + 0×2 + 1×1 = 13 in decimal.
Which of the following is an impact printer, in which pins strike an inked ribbon to form characters on paper?
Answer: (1) Dot-matrix printer
Explanation
A dot-matrix printer is an impact printer; laser, inkjet and thermal printers are non-impact printers.
Consider the following statements about the characteristics of a computer: 1. A computer can work for long hours without tiredness or loss of concentration (diligence). 2. A computer has its own intelligence and can decide what to do without any instructions. 3. If wrong data is fed in, the computer gives wrong results ('Garbage In, Garbage Out'). Which of the statements given above are correct?
Answer: (3) 1 and 3 only
Explanation
Statements 1 and 3 are correct. A computer has no intelligence (IQ) of its own; it works only according to the instructions (program) given to it.
In a hierarchical file system, the top-most directory of a drive, from which all other folders branch out, is called the:
Answer: (1) Root directory
Explanation
The root directory (for example C:\ in Windows or / in Linux) is the top level of a drive; all other folders are its sub-directories.
Arrange the following in increasing order of access speed (slowest first): 1. Cache memory 2. Hard disk 3. CPU registers 4. RAM (main memory)
Answer: (4) 2, 4, 1, 3
Explanation
In the memory hierarchy, speed rises from secondary storage (hard disk) to RAM, then cache, and registers inside the CPU are the fastest.
Consider the following statements: 1. Static RAM (SRAM) must be refreshed periodically, which makes it slower than Dynamic RAM (DRAM). 2. DRAM stores each bit in a capacitor and must be refreshed periodically to retain its data. 3. The contents of an EEPROM can be erased and rewritten electrically. Which of the statements given above are correct?
Answer: (2) 2 and 3 only
Explanation
Statements 2 and 3 are correct. SRAM uses flip-flops, needs no refreshing and is faster than DRAM (hence used as cache); EEPROM is Electrically Erasable Programmable ROM.
The original ASCII code uses 7 bits to represent each character. How many different characters can it represent?
Answer: (4) 128
Explanation
n bits give 2ⁿ patterns, so 7 bits give 2⁷ = 128 codes, which is why original ASCII has 128 characters. NCERT (Class 11 Computer Science, Encoding Schemes) adds that ISCII keeps all 128 ASCII codes and uses the other 128 for Indian-language characters. The figure 256 is wrong here because it needs 8 bits.
Match List-I (pioneer) with List-II (contribution to computing): List-I: A. Blaise Pascal B. Charles Babbage C. Herman Hollerith D. John von Neumann List-II: i. Punched-card tabulating machine used in a census ii. Mechanical adding machine built in 1642 iii. Stored-program concept iv. Analytical Engine
Answer: (1) A-ii, B-iv, C-i, D-iii
Explanation
Pascal built the Pascaline (1642), a mechanical adder; Babbage designed the Analytical Engine (1834), with a store and a mill, and is called the father of the computer; Hollerith's punched-card tabulator was used for the 1890 US census; von Neumann (1945) proposed keeping the program in memory along with the data. The code with B-i and C-iv swaps Babbage and Hollerith because both worked with punched cards, but the census tabulator was Hollerith's.
Which of the following binary–decimal pairs is NOT correct?
Answer: (1) (11011)₂ = 26
Explanation
(11011)₂ = 16 + 8 + 2 + 1 = 27, not 26. The others are right: 11001 = 16 + 8 + 1 = 25, 10011 = 16 + 2 + 1 = 19 and 10101 = 16 + 4 + 1 = 21.
Which language translator converts an entire high-level language program into machine code in one go, before the program is run?
Answer: (4) Compiler
Explanation
A compiler translates the whole source program at once and reports its errors together. An interpreter translates and runs line by line, and an assembler translates assembly language, not a high-level language.
Which of the following is NOT system software?
Answer: (1) MS PowerPoint
Explanation
MS PowerPoint is application software used to make presentations. System software runs and manages the hardware: operating systems, device drivers and utility programs such as disk cleanup.