C Programming MCQ Questions and Answers Basics 2

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C MCQ Questions and Answers

Learn C Programming MCQ Questions and Answers on Basics to attend job placement exams, interview questions, college viva and Lab Tests. This paper covers C language invention history, standards and usages.

Go through C Theory Notes on Basics before studying questions.



1) Choose correct answer..
#include<stdio.h>
main()
{
	/* Multi Line Comment
	This line is ignored by compiler
	*/
	printf("Hello C.."); 
}
A) #include is a Preprocessor Directive
B) <stdio.h> is a header file with predefined functions like printf, scanf etc
C)
#include
main()
{

}
is a mandatory function to be included in every C Program.
D) All the above
Answer [=]
D
2) Correct way of commenting a single line is.?
A) /*printf("Hello C.."); printf("How are you.");  
B) //printf("Hello C.."); printf("How are you.");
C) /*printf("Hello C.."); printf("How are you.");*/
D) /printf("Hello C..");/ printf("How are you.");
Answer [=]
B
Explanation:

Answer C comments two lines with Multi-Line comment or BLOCK Comment characters /* ....*/

Only // is a Single Line Commenting characters.

3) Single Line Comment // is also called.?
A) C++ Style Comment
B) Java Style Comment
C) PHP Style Comment
D) All the above
Answer [=]
D
4) Choose the correct answer.?
A) Digraph <: represents [ Digraph :> represents ] Digraph <% reprsents { Digraph %> reprsents } Digraph %: represents # Digraph %:%: represents ##
B) Digraph <: represents ] Digraph :> represents [ Digraph <% reprsents { Digraph %> reprsents } Digraph %: represents # Digraph %:%: represents ##
C) Digraph <: represents ] Digraph :> represents [ Digraph <% reprsents } Digraph %> reprsents { Digraph %: represents $ Digraph %:%: represents $$
D) Digraph <: represents { Digraph :> represents } Digraph <% reprsents [ Digraph %> reprsents ] Digraph %: represents / Digraph %:%: represents //
Answer [=]
A
Explanation:

Some keyboards in some countries do not contain Punctuation Keys. They have to use these Digraphs to represent the corresponding characters.

Eg.

int ary[] = { 1, 2}; is written as int ary<::> = <%1, 2%>;

Trigraphs are also present to support 1991 standard of representing 7 bit characters. ??( represents [.

5) What is an Identifier in C Language.?
A) Name of a Function or Variable
B) Name of a Macros
C) Name of Structure or Union
D) All the above.
Answer [=]
D
Explanation:

int age=25;

//here age is an Identifier

6) An Identifier may contain.?
A) Letters a-z, A-Z in Basic character set. Unicode alphabet characters other languages
B) Underscore _ symbol
C) Numbers 0 to 9 Unicode Numbers in other languages
D) All the above
Answer [=]
D
7) What is the number of characters used to distinguish Identifier or Names of Functions and Global variables.?
A) 31
B) 32
C) 33
D) 28
Answer [=]
A
Explanation:

First 31 characters in general. If first 31 characters are same for two different identifiers, compiler gets confused.



8) What is length of an Identifier that is unique for Non Global Variables and Non Function Names.?
A) 32
B) 63
C) 64
D) 68
Answer [=]
B
Explanation:

if 31 is present choose. Because old compilers support up to 31 only.

Upto first 63 characters you can show differentiation in the name of say 

int abcdefghijklmnopqrstuvwxyz1234567788= 10;

int abcdefghijklmnopqrstuvwxyz1234567799 = 20;

9) An Identifier can start with.?
A) Alphabet
B) Underscore ( _ ) sign
C) Any character that can be typed on a keyboard
D) Option A & Option B
Answer [=]
D
Explanation:

Identifier is just a name given to a Function, Variable etc.

Identifier name should contain only Letter, Numbers and Underscore.

10) C Programs are used in .?
A) Any Electronic device which works on some logic and Operating System.
B) Washing machine
C) Fridge, Microwave Ovens
D) All the above.
Answer [=]
D
Explanation:

C is very fast to execute and safe to embed along with microprocessors. Device drivers are written in C and C++.

11) What are the types of Constants in C Language.?
A) Primary Constants
B) Secondary Constants
C) Basic Constants and Advanced Constants
D) Primary Constants and Secondary Constants
Answer [=]
D
Explanation:

Primary Constants are Integer (int), Floating Point (float) , Character (char)

Secondary Constants are Structure, Union, Array and Enum.

12) Choose correct statements
A) A constant value does not change. A variable value can change according to needs.
B) A constant can change its values. A variable can have one constant value only.
C) There is no restriction on number of values for constants or variables.
D) Constants and Variables can not be used in a singe main function.
Answer [=]
A
Explanation:

Constant value is always constant. Constant is also called Literal.

Variable can have any number of arbitrary values and once value at any point of time. Variable is also called Identifier.

13) Find an integer constant.
A) 3.145
B) 34
C) "125"
D) None of the above
Answer [=]
B
Explanation:

Integer constant is a full or whole number without any decimal point. So 3.14 is a floating point number or Real number.

14) Find a Floating Point constant.
A) 12.3E5
B) 12e34
C) 125.34857
D) All the above.
Answer [=]
D
Explanation:

Floating Point can be represented in two forms.

1. Fractional Form

eg. 12345.67

2. Exponential Form

(Mantissa)e(number) or (Mantissa)E(number)

eg. 123.4567E2

(e2  = 10 power 2 = 100)



15) Find a Character constant.
A)
'A'
'a'
B)
'1'
'9'
C)
'$'
'#'
D) All the above.
Answer [=]
D
Explanation:

A character constant contains only one character within Single Quotes. ' '. Single Quote is typed using Single Quote Double Quote Key near Enter Key in a Keyboard. Simply it is Right Single Quote.

Left Single Quote looks like this `

Right Single Quote looks like this '

16) A Variable of a particular type can hold only a constant of the same type. Choose right answer.
A) TRUE
B) FALSE
C) It depends on the place the variable is declared.
D) None of the above.
Answer [=]
A
Explanation:

An int can hold only Integer constant.

A float can hold only Real Number constants.

A char can hold only Character constants.

17) Choose a right statement.
A) int myage = 10; int my_age = 10;
B) int myage = 10; int my,age = 10;
C) int myage = 10; int my age = 10;
D) All are right
Answer [=]
A
Explanation:

Only Underscore ( _ ) symbol is allowed in a variable name i.e identifier name. Space, Comma and other special characters are not allowed.

18) Number of Keywords present in C Language are .?
A) 32
B) 34
C) 62
D) 64
Answer [=]
A
Explanation:

Only 32 Keywords originally. Compilers are individual companies can include and use extra keywords if required. Such keywords should preceed with __ ( two Underscore symbols before names).

eg. __mykeyword

19) Each statement in a C program should end with.?
A) Semicolon ;
B) Colon :
C) Period . (dot symbol)
D) None of the above.
Answer [=]
A
Explanation:

e.g

int amount = 10;

float a,b;

20) Choose a correct statement.
A) C Compiler converts your C program into machine readable language.
B) C Editor allows you to type C Programs. It is just like a Notepad with extra options.
C) Console shows the output of a C Program if it is text output.
D) All the above
Answer [=]
D