How to declare a wide character in the string literal?

The rule for implicit type conversion in 'C' is

What will be the output of the following C code?

#define sqr(x) x*x
main()
{
    int a1;
    a1=25/sqr(5);
    printf("%d",a1);
}

What is the use of "#pragma once"?

Assume integer is 2 bytes wide. What will be the output of the following code?

#include
#include
#define MAXROW 3
#define MAXCOL 4

int main()
{
    int (*p)[MAXCOL];
    p = (int (*) [MAXCOL])malloc(MAXROW *sizeof(*p));
    printf("%d, %d\n", sizeof(p), sizeof(*p));
    return 0;
}

Which header file should be included to use functions like malloc() and calloc()?

What will be the output of the program (myprog.c) given below if it is executed from the command line?
cmd> myprog one two three

/* myprog.c */
#include
#include

int main(int argc, char **argv)
{
    printf("%s\n", *++argv);
    return 0;
}

Find the output of below C program

#include "stdio.h"

typedef enum{
    Male, Female
}SEX;

int main()
{
  SEX var = Male;
  printf("%d",var);
  return 0;

}

The following program

main( )
{
static int a[ ] = { 7, 8, 9 } ;
printf( "%d", 2[ a ] + a[ 2 ] ) ;
}

C does no automatic array bound checking. This is 

What will be the output of the program?

#include
int main()
{
    int i = 1;
    switch(i)
    {
        printf("Hello\n");
        case 1:
            printf("Hi\n");
            break;
        case 2:
            printf("\nBye\n");
            break;
    }
    return 0;
}

What will be the output of the program?

#include
int main()
{
    float a = 0.7;
    if(0.7 > a)
        printf("Hi\n");
    else
        printf("Hello\n");
    return 0;
}

What will function gcvt() do?

Bitwise can be used to perform addition and subtraction.

What will be the output of the program ?

#include
#include

int main()
{
    char sentence[80];
    int i;
    printf("Enter a line of text\n");
    gets(sentence);
    for(i=strlen(sentence)-1; i >=0; i--)
        putchar(sentence[i]);
    return 0;
}

What will be the output of the following C code?

char str1[] = "Helloworld ";
char str2[] = "Hello";
len = strspn(str1, str2);
printf("Length of initial segment matching %d\n", len );

What is the output of this C code?

void main()
{
int x = 0;
int *ptr = &5;
printf("%p\n", ptr);
}

What is the output of this C code?

void main()
{
int x = 0;
int *ptr = &x;
printf("%p\n", ptr);
ptr++;
printf("%p\n ", ptr);
}

What will be the output of the following C code?

#include 
    int main()
    {
        int i = 97, *p = &i;
        foo(&i);
        printf("%d ", *p);
    }
    void foo(int *p)
    {
        int j = 2;
        p = &j;
        printf("%d ", *p);
    }

What is the output of this C code?    

int main()
    {
        int i = 10;
        int *p = &i;
        printf("%d\n", *p++);
    }