RRB JE IT (CBT II) Mock Test- 2 - Computer Science Engineering (CSE) MCQ

Machine Language

Machine Language is the language written as strings of binary 1's and O's. It is the only language which a computer understands without using a translation program. A low-level language is a machine language.

Assembly Language

It is a high-level programming language that allows a user to write a program using alphanumeric mnemonic codes, instead of numeric codes for a set of instructions. It requires a translator known as assembler to convert assembly language into machine language so that it can be understood by the computer. It is easier to remember and write than machine language.

• Volcano Popocatepetl, whose name is the Aztec word for Smoking Mountain, towers to 5426 m 70 km SE of Mexico City to form North America's 2nd-highest volcano.

• This type of mountain is a stratovolcano or a composite volcano.

The Output is high only when all the inputs are high

• An information system has five key components hardware, software, data, processes, and people.

• Hardware consists of everything in the physical layer of the information system. For example, hardware can include servers, workstations, networks etc.

• Software refers to the programs that control the hardware and produce the desired information or results. Software consists of system software and application software.

• People who have an interest in an information system are called stakeholders. Stakeholders include the management group responsible for the system.

• A computer worm is a standalone malware computer program that replicates itself in order to spread to other computers.

• Ransomware is a type of malware from cryptovirology that threatens to publish the victim's data or perpetually block access to it unless a ransom is paid.

• Keystroke logging often referred to as keylogging or keyboard capturing, is the action of recording (logging) the keys struck on a keyboard, typically covertly, so that person using the keyboard is unaware that their actions are being monitored.

• A Trojan horse, or Trojan, is any malware that misleads users of its true intent.

Class A: 1 - 126

Class B: 128 – 191

Class C: 192 - 223

Class D: 224 - 239

Class E: 240 - 254

In IP address 125.250.250.250, the first octet is 125 which lies in range 1 - 125 of class A.

The ?: operator is a ternary operator

expression? statement1: statement2

if the expression is true, then statement1 is the return

if the expression is false, then statement2 is the return

expression is false since b = 2, that is, b ≠ 0

∴ tb = 20

Output: Ternary operator: 20

The integer printed in the output is 20.

• Non-impact printers print the characters without using ribbons, These printers print a complete page at a time so they are also called page printers. E.g. Ink-Jet printer, Laser printer

• The impact printers print the characters by striking them on the ribbon which is then pressed on the paper, E.g. Drum printer, chain printer, Dot matrix printer

To execute any last executed command, just type double exclamation marks, and hit ENTER:

$ !!

This will execute the last command.

Add “sudo” in front of “!!” to execute the last command as root user like below.

$ sudo !!

NRZ – L: Non-Return to Zero – Level

NRZ – L: level of voltage decides the value of bit

NRZ – I: Non-Return to Zero - Invert

NRZ – I: Change or lack of change in the voltage level determines the value of the bit. If there is no change, the bit is 0; if there is a change, the bit is 1.

Unipolar: All the signals are on one side of the time axis, either above or below, Unipolar NRZ has only one level of voltage.

Example:

If TestBook is a class

TestBook mytestbook; // declare reference to object

mytestbook = new TestBook(); // allocate a Box object

Important Points:

In C programming language:

• malloc() function is used to allocate a block of memory. A block of memory with a particular size is reserved and a pointer is returned which is of type void meaning that this function can be assigned to any type of pointers.

• calloc() function is used when there is a need for multiple blocks of storage, of the same size, and then set all bytes to zero.

• sizeof() is an operator to find the size of a variable in bytes.

In Java, all variables must be declared before they can be used. The basic form of a variable declaration is:

type identifier [ = value ][, identifier [= value ] …];

Examples:

int a, b;

int a = 10, b = 20, c = 30;

int a, b = 20, c;

char a = ‘3’

In option 4, data type is a char but data assigned to char is not present in single quotes. Therefore, it is an invalid assignment in Java.

the phase is known as the development phase.

Phases of classical waterfall model:

Feasibility study

↓

Requirements analysis and specification

↓

Design

↓

Coding and unit testing

↓

Integration and system testing

↓

Maintenance

Therefore, maintenance is not the development phase of the classical waterfall model.

Dust Particles

The atmosphere has a sufficient capacity to keep small solid particles, which may originate from different sources and include sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors.

Dust and salt particles act as hygroscopic nuclei around which water vapour condenses to produce clouds.

Primary memory can be divided into RAM (Random Access Memory) and ROM (Read Only Memory)

• When fats and oils are oxidised, they become rancid and their smell and taste change.

• Substances which prevent oxidation (antioxidants) are added to foods containing fats and oil.

• Manufacturers flush bags of chips with gas such as nitrogen to prevent the chips from getting oxidised.

• Keeping food in air-tight containers helps to slow down oxidation.

• An information system has five key components: hardware, software, data, processes, and people.

• Hardware consists of everything in the physical layer of the information system. For example, hardware can include servers, workstations, networks, telecommunications equipment, fiber-optic cables, mobile devices, scanners, digital capture devices, and other technology-based infrastructure.

Linux Directories

/ is the root directory.

/bin and /usr/bin store user commands.

/boot contains files used for system startup including the kernel.

/dev contains device files.

/etc is where configuration files and directories are located.

/home is the default location for users’ home directories.

The ideal resistance of ammeter is zero, Hence voltage drop across it (IR=0)

Thus voltmeter shows 0 reading

• To create a function in user schema, user must have the CREATE PROCEDURE system privilege

• To create a function in another user's schema, user must have the CREATE ANY PROCEDURE system privilege

• To replace a function in another user's schema, user must have the ALTER ANY PROCEDURE system privilege

• The Table Tennis Federation of India (TTFI) has appointed the Canadian Dejan Papic as the head coach of the Indian table tennis team.

• He has signed a one-year contract and will be in charge through the 2020 Tokyo Olympics.

• Papic will be paid USD 7000 per month and his contract will be up for renewal after the Olympics.

For example, the first time a user visits a site they may choose a username which is stored in the cookie, and then provide data such as password, name, address etc.

The programs open and save files as windows bitmaps.

• JPEG: Joint Photographic Experts Group

• GIF: Graphics Interchange Format

• PNG: Portable Network Graphics

• TIFF: Tagged Image File Format

.doc is a filename extension for word processing documents (MS Word).

• Combination of letter (A-Z) and digit (0-9) are used as identifier but identifier should not start with digit

Example: ext321ern and extern21 are valid identifier

• extern is a reserved word in C programming language, hence it cannot be used as an identifier

• Underscore “_” is counted as a letter so it can be used as a variable name

• extern is reserved word in C but _extern is not reserved hence could be used as a variable name

e.g. int extern; // is not a valid variable name