UPSC CISF-AC-EXE

Which one of the following is not a raster image format ?

[amp_mcq option1=”JPEG” option2=”GIF” option3=”PNG” option4=”SVG” correct=”option4″]

A raster image format stores images as a grid of pixels, where each pixel contains colour information. JPEG, GIF, and PNG are all popular file formats that store images using this pixel-based approach. SVG (Scalable Vector Graphics), on the other hand, is a vector image format. Vector images are composed of mathematical descriptions of geometric shapes, lines, and curves, making them scalable without loss of quality.

Raster images are pixel-based, while vector images are based on mathematical descriptions. SVG is a vector format.

Common raster formats include BMP, TIFF, and WebP in addition to JPEG, GIF, and PNG. Vector formats are often used for logos, illustrations, and graphics that need to be resized frequently because they scale smoothly without pixelation.

Which one of the following is a technique of dividing the physical memory space into multiple blocks ?

[amp_mcq option1=”Fragmentation” option2=”Paging” option3=”Segmentation” option4=”Swapping” correct=”option2″]

Paging is a memory management technique that divides the physical memory (RAM) into fixed-size units called frames and the logical address space of a process into equally sized units called pages. It is a method of dividing physical memory into blocks (frames) to facilitate non-contiguous memory allocation and virtual memory implementation.

Paging divides physical memory into fixed-size frames and logical memory into same-size pages, enabling processes to be loaded into non-contiguous physical memory locations.

Fragmentation refers to wasted space in memory. Segmentation divides logical memory into variable-size segments based on the program’s structure. Swapping is a technique to move processes between memory and disk to manage limited physical memory resources, not a method of dividing physical memory into blocks for allocation.

The result of binary subtraction between 1001 and 101 is :

[amp_mcq option1=”1011″ option2=”1001″ option3=”001″ option4=”100″ correct=”option4″]

To subtract 101 (binary) from 1001 (binary), we perform binary subtraction:
1001 (which is 9 in decimal)
– 0101 (which is 5 in decimal, added a leading zero for alignment)
——-
Starting from the rightmost bit:
1 – 1 = 0
0 – 0 = 0
0 – 1: Cannot subtract. Borrow from the leftmost digit (1). The leftmost 1 becomes 0. The borrowed 1 moves to the left, making the next position 2 (in base 2). So, we have 2 – 1 = 1.
The leftmost digit is now 0.
Result: 0100 (binary), which is 100 (binary) when the leading zero is dropped.
100 (binary) is 1*2^2 + 0*2^1 + 0*2^0 = 4 (decimal). 9 – 5 = 4.

Binary subtraction follows similar principles to decimal subtraction, using borrowing when a smaller digit is being subtracted from a larger one.

Binary arithmetic is fundamental in digital electronics and computer science. Subtraction can also be performed using two’s complement representation and binary addition. In this case, direct subtraction is straightforward.

Debugger is a :

[amp_mcq option1=”Software.” option2=”Hardware.” option3=”Combination of software and hardware.” option4=”None of the above” correct=”option1″]

A debugger is a software tool used by programmers to test and find errors (bugs) in other software programs. It allows developers to step through code execution, inspect variables, and analyze program behaviour to identify the root cause of issues.

Debuggers are software applications used to aid in the process of software development by helping to locate and fix errors in code.

While debugging hardware systems (like embedded systems) may involve hardware interfaces (like JTAG adapters), the debugger application running on a host computer is fundamentally a piece of software. The question asks what the debugger *is*, referring to the tool itself.

How many input lines are there in the NOT gate ?

[amp_mcq option1=”2″ option2=”1″ option3=”3″ option4=”4″ correct=”option2″]

A NOT gate, also known as an inverter, is a basic digital logic gate that performs logical negation. It takes a single binary input and produces an output that is the opposite logic level (0 becomes 1, and 1 becomes 0). Therefore, it has exactly one input line.

The NOT gate is a unary operation, meaning it operates on a single input.

Other basic logic gates like AND, OR, XOR, NAND, and NOR typically have two or more input lines. The output of a NOT gate is always the complement of its input.

How many bits combination is present in a Byte?

[amp_mcq option1=”2″ option2=”4″ option3=”8″ option4=”16″ correct=”option3″]

A byte is the fundamental unit of data storage in computer systems, typically defined as a sequence of 8 bits.

A byte consists of 8 bits, which is the smallest addressable unit of memory for most modern computer architectures.

A bit is the smallest unit of data, representing a binary value (0 or 1). A group of 4 bits is called a nibble. Larger units include words, which consist of varying numbers of bytes depending on the computer architecture (e.g., 2 bytes for a 16-bit word, 4 bytes for a 32-bit word, 8 bytes for a 64-bit word).

1 KB is equivalent to :

[amp_mcq option1=”1042 bytes.” option2=”1023 bytes.” option3=”1021 bytes.” option4=”1024 bytes.” correct=”option4″]

In the context of computer memory and storage, 1 KB (Kilobyte) is conventionally understood as 2¹⁰ bytes.

The standard definition of a Kilobyte in computing is 1024 bytes, based on powers of 2 (2¹⁰).

While the SI definition of kilo (k) is 10³ (1000), computer science traditionally uses powers of 2. This led to ambiguity, and standards bodies like IEC introduced prefixes like kibi (Ki) for 2¹⁰ (1024) and kilo (k) for 10³ (1000). However, in common usage for memory sizes, KB still widely refers to 1024 bytes. For storage devices like hard drives and network speeds, kilo often means 1000. Given the options, 1024 is the expected answer for a computer science context.

Which one of the following is a sequential electronic circuit that is used to store 1-bit information?

[amp_mcq option1=”Register” option2=”Flip-flop” option3=”Counter” option4=”Accumulator” correct=”option2″]

A flip-flop is a basic sequential logic circuit that has two stable states and can store one bit of binary information (0 or 1). It is the fundamental building block for memory elements in digital electronics.

Flip-flops are the elementary memory units in sequential circuits, capable of storing a single bit of data and changing state based on input signals and clock pulses.

A register is a collection of multiple flip-flops used to store a group of bits (e.g., a byte or a word). A counter is a sequential circuit that cycles through a sequence of states, often counting pulses, and is typically constructed using flip-flops. An accumulator is a type of register used in central processing units (CPUs) for performing arithmetic and logic operations.