Computers Aptitude

Correct Answer: address

Linux is an open source software which is assembled under the model of free and open-source software development and distribution.

Internal memory (RAM) is the primary memory that directly communicates with the CPU. It holds the programs and data currently being executed because the CPU can only directly access data in internal memory. Mass memory is secondary storage, non-volatile memory retains data without power, and PROM is a type of read-only memory.

Soft copy refers to output displayed on screen that exists only while powered. Hard copy is a permanent printed version. Print copy refers to hard copy, and VDU (Visual Display Unit) is the monitor hardware itself. The term 'soft copy' specifically denotes temporary, screen-based output.

An offline device is not connected to or under the direct control of the CPU. Offline devices operate independently and require manual intervention to connect or transfer data. Online devices remain connected and communicate directly with the CPU. The term specifically refers to the disconnected state.

Peopleware refers to the human personnel involved in computing - those who design, program, operate, and maintain computer equipment. This includes programmers, operators, analysts, and support staff. The other options are specific roles, while peopleware is the collective term for all computer personnel.

Fields are the distinguishable parts or individual data elements within a record. A record contains multiple fields (like name, age, address in an employee record). Files are collections of records, data is the general term for information, and a database is an organized collection of related data. Fields are the smallest named units.

An assembler converts assembly language (mnemonic instructions like MOV, ADD) to machine language (binary code the CPU executes). Compilers translate high-level languages to machine code, interpreters execute high-level code directly, and comparators compare data files. The assembler specifically handles assembly-to-machine translation.

Spreadsheets are specifically designed for financial calculations, planning, and numerical analysis. They provide formulas, functions, and grid layouts perfect for budgets, financial projections, and calculations. Graphics software creates images, communication software transfers data, and databases organize structured information. Spreadsheets excel at numerical computation.

RAM is called short-term memory because it is volatile - it loses all data when power is removed. This volatility makes it temporary storage for active programs and data. While RAM is expensive and has smaller capacity than secondary storage, its volatility is the key reason it's considered 'short' memory. Programmability is irrelevant to this classification.

The 'cp' command (copy) is the standard Unix command for copying files. Unix uses abbreviated commands - cp for copy, mv for move, rm for remove. The 'copy' command exists in other systems like Windows/DOS. Cpio is an archive tool, and tar creates archives, not file copies. Unix documentation confirms 'cp' as the copy command.

Inserting a date field ensures automatic updates whenever the document is opened or printed. This is the professional approach as it stays current without manual intervention. Typing dates manually or inserting constant text requires repeated updates. Text dates don't update automatically. Date fields are designed for dynamic, self-updating timestamps.

C++ is a multi-paradigm programming language that supports object-oriented programming. While it also supports procedural and generic programming, its key feature is object-oriented capabilities like classes, inheritance, and polymorphism. Low-level languages (like assembly) and machine languages are closer to hardware, while C++ provides abstraction with hardware access when needed.

Before writing any code or planning solutions, you must first understand what problem you're trying to solve. Analysis involves understanding requirements, identifying inputs/outputs, and recognizing constraints. Planning algorithms (B) comes after analysis, desk-checking (C) validates the algorithm, and coding (D) is the implementation phase.

Sequence is fundamental - every program executes statements sequentially (one after another) by default. Even the simplest program must execute statements in order. Selection (if/else) and repetition (loops) are optional control structures that programs may or may not use. "Switching" is not a standard control structure category.

Preprocessor directives in C++ always begin with a hash symbol (#). Examples include #include for header files, #define for macros, and #ifdef for conditional compilation. The preprocessor processes these directives before actual compilation. Double slashes (//) are for single-line comments, ampersand (&) is the address-of operator, and less-than (<) is a comparison operator or used in include statements.

The conditional (ternary) operator in C++ is ?: (question mark and colon). It's the only operator that takes three operands: condition ? value_if_true : value_if_false. For example: max = (a > b) ? a : b;. Double ampersand (&&) is logical AND, double pipeline (||) is logical OR, and a single question mark (?) alone is not a valid operator.

The getline(cin, mystring) function reads a complete line of text from the input stream (cin) and stores it in the string variable mystring. Unlike cin >> mystring which stops at whitespace, getline reads until a newline character. Option B is reversed (cin is the source, not destination). Option C is incorrect because getline is a standard valid function.

main() is the designated entry point where C++ program execution begins. When you run a C++ program, the operating system calls the main() function first. Options like Start(), Begin(), or Output() are not standard entry points in C++. The exact signature is typically int main() for standards-compliant code.

When arguments are passed by value, the function receives copies of the original values. Any modifications made to x and y inside the function affect only the local copies - the original variables outside remain unchanged. This is why pass-by-reference (using &) is needed when you want modifications to affect the originals. Option C describes pass-by-reference behavior, and option D is incorrect because function results can be assigned to variables.

x (without quotes) refers to a variable named x, which is a named storage location in memory. 'x' (with single quotes) is a character constant representing the character 'x'. In C++, single quotes denote character constants while unquoted names are identifiers/variables. Option B is wrong because string literals use double quotes ("x"), and option D is incorrect because 'x' is a character constant, not a pointer.

Preprocessor directives are lines processed by the preprocessor before compilation. They begin with # and include commands like #include, #define, #ifdef. Option A correctly states this. Option B is incorrect because directives like #define DO produce code (macro expansion). Option C is wrong because directives must be written BEFORE main, not within it. Option D is incorrect because directives don't end with colons - they're line-based.

A variable is a named portion of memory that stores a value that can change during program execution. The key aspects are: 1) It occupies memory space, 2) It holds a value, 3) The value can vary (hence "variable"). Option A is incorrect because variables are not strings themselves - they have names and store values. Option C describes constants, not variables. Option D describes constants/literals, which are fixed values.

Missing a header file like math.h means the compiler cannot find function declarations for math functions. In modern C/C++ standards (C99+, C++), this causes a compilation error because implicit function declarations are not allowed. The compiler needs to see function prototypes to validate function calls.

A selection statement allows the program to choose between different execution paths based on a condition. In C++, 'switch' is a selection statement that selects one of many code blocks to execute. 'break' is used within loops and switch to exit, 'goto' is an unconditional jump, and 'exit' is a library function that terminates the program.

Pass by reference means passing the memory address (location) of the variable to the function. This allows the function to directly access and modify the original variable in memory, rather than working with a copy. Changes made inside the called function affect the original variable in the calling function.

The while loop increments s using post-increment (s++). Initially s=0, after check s becomes 1. The condition (s<4 && s<9) is true for s=1,2,3, so continue skips printf. When s=4, the condition fails and printing starts. Output continues through s=10 when the loop condition (10<10) becomes false. Output: 4 5 6 7 8 9 10

A class serves as a blueprint or template that defines the structure and behavior common to all objects of that type. It specifies what data (variables/attributes) and operations (methods/functions) every object created from that class will have. Objects are instances created from this blueprint.

The 'void' return type specifically indicates that a function does not return any value to the caller. It is a valid and commonly used data type in C/C++ for functions that perform actions without producing a return value. Option A incorrectly describes void as a memory area, void is not about returning a memory area to populate.

When an array is passed as an argument to a function, it 'decays' into a pointer to its first element. The function receives the memory address of element [0], not a copy of all elements or the count. This is why array parameters are often accompanied by a separate size parameter - the pointer alone doesn't convey array length.

When a signed integer overflows (value exceeds maximum representable), it wraps around due to two's complement representation. The most significant bit (sign bit) flips, making the value negative. For example, if INT_MAX is 2147483647, adding 1 gives -2147483648 (INT_MIN). This is undefined behavior in C/C++ but typically results in wraparound.

Method overloading allows a class to have multiple methods with the same name but different parameter lists (different number or types of parameters). The compiler selects which version to call based on the arguments passed. This is different from overriding (replacing a parent class method) and enables method behavior to vary based on input types.

Binary search IS efficient (O(log n)) even for large datasets - its power grows with size. The real limitations are: A) it requires a sorted array, B) maintaining sorted order is costly with frequent insertions/deletions (requires resorting or complex data structures), and C) it needs direct middle element access (random access, not suitable for linked lists). Option D is NOT a limitation.

Recursion solves problems by breaking them into smaller instances of the same problem. The function calls itself with reduced input until reaching a base case. This divide-and-conquer approach is the essence of recursive thinking. Options A and B are incorrect - recursion has valid uses and is not about writing less code. Option C is wrong - recursion is not always most efficient due to overhead.

When p = num, p points to the first element. Array indexing num[i] is equivalent to *(num + i) or *(p + i). Option A is wrong because p+1 is an address, not a value. Option B is syntactically invalid - &(p+2) doesn't make sense. Option C is correct: num[3] = *(p+3) dereferences the pointer to get the value. Option D is wrong: *p gives the first element's value (3), not the array itself.

fstream is the correct C++ class for file operations that require both input and output capabilities. The ios::in | ios::out flags indicate we need to both read from and write to the file, which fstream supports. iostream only handles console I/O, while ifstream and ofstream are specialized for input-only or output-only operations respectively.

Constructors have the same name as their class (statement II is true) and can be overloaded to provide multiple initialization options (statement III is true). Statement I is false because while constructors have no return type, they are not void methods. Statement IV is false because constructors are called automatically during object creation, not like regular methods.

Encapsulation is the OOP principle of hiding implementation details (data and method internals) from users of the class. This allows the class designer to modify internal implementation without affecting code that uses the class, as long as the public interface remains stable. Data binding, polymorphism, and inheritance are related but distinct concepts.

Queues are specifically designed as FIFO (First-In-First-Out) data structures where elements are removed from the front and inserted at the rear. Stacks use LIFO order (last-in-first-out). Linked lists allow insertion/deletion at any position, and bubble sort is a sorting algorithm, not a data structure.

To convert (a + b) * (c - d) / (e + f) to postfix: first convert each subexpression (a+b)→ab+, (c-d)→cd-, (e+f)→ef+, then apply operators: ab+ cd- * gives the product, then ab+cd-* ef+ / gives the final division. Option B correctly shows: ab+ cd- * ef+ /. The other options either apply operators in wrong order or have misplaced operands.

Pop is the standard term for removing an element from a stack, operating on the top element following LIFO (Last-In-First-Out) order. Delete is too generic, peek views without removing, and remove is not the conventional terminology for stack operations in computer science.

The formula for calculating memory address uses: Base Address + (Index - Lower_Bound) × Word_Size. Option A correctly shows this pattern (despite minor notation issues). Options B and C incorrectly index into the array rather than using the base address. Option D uses Upper bound instead of Lower bound in the offset calculation, which is incorrect.

George Boole (1815-1864) was the English mathematician who invented Boolean algebra in the mid-19th century, establishing the mathematical foundation for logical operations that later became fundamental to computer circuit design and programming. Von Neumann contributed to computer architecture, Knuth to algorithms, and Babbage to early computing mechanical devices.

To convert 1000 from base-10 to base-5: divide repeatedly by 5. 1000 ÷ 5 = 200 remainder 0, 200 ÷ 5 = 40 remainder 0, 40 ÷ 5 = 8 remainder 0, 8 ÷ 5 = 1 remainder 3, 1 ÷ 5 = 0 remainder 1. Reading remainders bottom-to-top: 13000. Verification: 1×5⁴ + 3×5³ + 0×5² + 0×5¹ + 0×5⁰ = 625 + 375 + 0 + 0 + 0 = 1000.

A queue follows FIFO (First-In-First-Out) ordering. When elements are enqueued as D, C, B, A, they exit in that same order: D first, then C, then B, then A. This is the defining behavior of queues versus stacks (LIFO). Option D correctly shows DCBA as the removal order.

A NOR gate outputs ON (logic 1) only when all inputs are OFF (logic 0). The NOR operation is equivalent to NOT-OR: it outputs 1 only when all inputs are 0, and outputs 0 if any input is 1. This makes it the logical complement of the OR gate.

Option C is always true by the law of excluded middle: either x >= 10 or x < 10 must hold. The expression 10 <= x || !(x >= 10) simplifies to (x >= 10) || !(x >= 10), which is a tautology. Option A is always false (contradiction). Options B and D are not tautologies - they assert specific arithmetic relationships between variables that may not hold.

Baud measures the number of signal units or symbols transmitted per second over a communication channel. It represents the rate at which data travels over the communication line. The other options are unrelated: memory capacity is measured in bytes, execution time in clock cycles or seconds, and a small initialization program is called a bootstrap loader.

The code uses assignment operator (=) instead of equality comparison operator (==). In C, the expression if (x = 100) assigns 100 to x and the condition always evaluates to true (non-zero), whereas if (x == 100) properly compares x with 100. This is a common programming error.

Traditional Ethernet (especially early versions like 10Base5 and 10Base2) uses bus topology where all devices share a common communication medium. Modern Ethernet using switches typically uses star topology, but the question asks about Ethernet's fundamental design. Ring topology is used by Token Ring, mesh in complex networks, and star requires a central hub.

Fiber optic transmission offers all three advantages: it is resistant to data theft (tapping fiber requires physical intrusion that breaks transmission), provides very high data rates (gigabits per second), and has low noise (immune to electromagnetic interference). Therefore 'All of the above' is the correct choice.

The function prints digits in reverse order. It repeatedly extracts the last digit using n % 10 (7, then 3, then 8 for 837) and divides n by 10. The do-while ensures at least one iteration. So f(837) prints '738' followed by newline. Option A is in reverse order, C and D are incorrect values.

In C, integer division (5/3) truncates toward zero, yielding 1 (not 1.66 or decimal values). The modulo operator (5 % 3) gives the remainder, which is 2. Therefore printf with '%d, %d' format prints '1, 2'. The fractional answers A, B, C are incorrect because %d expects integers.

In relational database terminology, a tuple refers to a single row or record in a table. It represents one complete set of related data values. A key is called a primary or foreign key (not tuple), an attribute is a column, and a table is a relation. The term comes from mathematical set theory.

SQL's SELECT statement implements the three fundamental relational operations: selection (choosing rows based on conditions via WHERE), projection (choosing columns via SELECT), and join (combining data from multiple tables via JOIN). Difference and intersection are other set operations, not the primary SELECT operations described.

From the truth table, Y is 1 only when A=1 (regardless of B). Using K-map simplification: minterms are A'B' (0,0→0), A'B (0,1→0), AB' (1,0→1), AB (1,1→1). The simplified expression is AB + AB' = A(B + B') = A(1) = A. Among the options, AB + AB' (option C) is equivalent to A and matches the truth table output.

Operator overloading allows programmers to redefine how built-in operators (like +, -, *, etc.) work with user-defined objects or data types. This enables intuitive syntax (e.g., adding complex numbers with a+b) and is a key feature of C++ polymorphism. It has nothing to do with overheating, parallel processing, or deadlock avoidance.