BPSC Assistant Maintenance Engineer Exam: 2019প্রশ্ন ও সমাধান

Correct answer: (c) Long Term Evolution

LTE stands for Long Term Evolution. The name comes from 3GPP, which around 2000 widened its work to the long-term evolution of the 3G (UMTS/UTRA) radio specifications; the resulting system, E-UTRA radio plus the all-IP Evolved Packet Core, became known as LTE. It is commonly marketed as 4G, although strictly the 4G (IMT-Advanced) benchmark was met by LTE-Advanced.

Why the other options are wrong

• (a) Long Term Evaluation: "Evaluation" means assessment; the standard is an evolution (step-by-step development) of 3G, not an evaluation.
• (b) Long Time Evaluation: Both "Time" and "Evaluation" are wrong; the words are Term and Evolution.
• (d) Long Terminal Evolution: "Terminal" is not part of the name; LTE covers the whole radio access and core network, not just the terminal.

Tip: LTE = Long Term Evolution: the evolution of 3G toward 4G.

Source: LTE - 3GPP

Correct answer: (a) (10DC)₁₆

Add column by column from the right, carrying 1 whenever a column reaches 16:

• 2 + A = 2 + 10 = 12 = C, carry 0
• 1 + C = 1 + 12 = 13 = D, carry 0
• B + 5 = 11 + 5 = 16 = 10₁₆ → write 0, carry 1
• The final carry 1 becomes the leading digit.

Result: (B12)₁₆ + (5CA)₁₆ = (10DC)₁₆.

Decimal check: B12₁₆ = 11 × 256 + 1 × 16 + 2 = 2834; 5CA₁₆ = 5 × 256 + 12 × 16 + 10 = 1482; 2834 + 1482 = 4316 = 1 × 4096 + 0 × 256 + 13 × 16 + 12 = 10DC₁₆ ✓

Why the other options are wrong

• (b) (AFDC)₁₆: = 45020, far larger than the true sum 4316.
• (c) (1FDC)₁₆: = 8156; it writes F in the third column instead of 0 (B + 5 = 16 must become 0 with a carry).
• (d) (E1DC)₁₆: = 57820, also far too large.

Tip: In hex, a column sum of 16 or more → subtract 16, write the remainder, carry 1.

Correct answer: (c) Method

A constructor is a special member function (a method, in OOP terms) that runs automatically when an object is created and initialises it. Three things set it apart from an ordinary method:

1. It has the same name as its class.
2. It has no return type, not even void.
3. It is not called by name like a normal function; it runs as part of creating the object (Point p(1, 2); or new Point(1, 2)).

In C++ a constructor is a non-static member function with a special declaration syntax. In Java, a constructor declaration looks like a method declaration except for the class name and the missing return type (the Java specification keeps constructors formally separate from methods, but in exam terms a constructor is a special method).

Why the other options are wrong

• (a) Class: A class is the blueprint that contains constructors, fields and methods; a constructor is one member of a class, not a kind of class.
• (b) Field: A field (data member) stores an object's state; a constructor is executable code that sets that state.
• (d) Property: A property (for example in C#) is a field-like member read and written through get/set accessors; a constructor is never used that way.

Tip: Constructor = special method: same name as the class, no return type, runs automatically when an object is created.

Sources: Constructors and member initializer lists - cppreference.com; Providing Constructors for Your Classes (The Java Tutorials, Oracle)

Correct answer: (d) None

The stem prints "MIRC", an evident misprint of MICR, which stands for Magnetic Ink Character Recognition. The characters along the bottom of a bank cheque (cheque number, bank/branch code, account number) are printed in ink that contains iron oxide, in a special font such as E-13B. A MICR reader magnetises the ink and recognises each character from the waveform it produces, so banks can sort and clear cheques automatically. Since no option ends in "Recognition", none of (a)–(c) is the correct full form.

Why the other options are wrong

• (a) Magnetic Ink Character Reader: the last word is wrong. The machine that scans cheques is a MICR reader, but the acronym's R stands for Recognition.
• (b) Magnetic Ink Code Reader: both "Code" and "Reader" are wrong.
• (c) Magnetic Ink Case Reader: "Case" and "Reader" are wrong.

Tip: MICR = Magnetic Ink Character Recognition; OCR = Optical Character Recognition; OMR = Optical Mark Recognition (or Reader).

Source: Information on Magnetic Ink Character Recognition (MICR) fonts (IBM Support)

Correct answer: (c) System calls

Files, memory, devices and similar resources are owned and managed by the operating system. A program therefore requests a resource and later releases it by asking the kernel through system calls, for example open() and close() for a file. This request → use → release cycle, with request and release performed as system calls, is also the standard model used when studying deadlocks.

Why the other options are wrong

• (a) Command line: a text interface through which a user runs programs; programs do not acquire or free resources through it.
• (b) Interrupt statements: interrupts are signals (from hardware, or traps) that make the CPU run a handler. A system call is entered through a trap instruction, but the request itself is the system call, not an "interrupt statement" written by the program.
• (d) Special program: too vague; there is no separate "special program" for this, and the defined mechanism is the system call.

Exam note: Option (b) was printed "Interrupts statements"; only the grammar has been fixed.

Tip: Request a resource → system call; release it → system call.

Source: Adding a New System Call (Linux kernel documentation)