Q5. What does calloc function in C do?
a) Allocates memory and initializes all bytes to zero
b) Allocates memory and initializes with random values
c) Allocates memory without initialization
d) Allocates memory with predefined values
Answer: a) Allocates memory and initializes all bytes to zero
Q6.What is the syntax for dynamically allocating memory for an integer variable in C?
a) int* ptr = malloc(sizeof(int));
b) int* ptr = malloc(int);
c) int* ptr = malloc(sizeof(int*));
d) int* ptr = malloc(size(int));
Answer: a) int* ptr = malloc(sizeof(int));
Q7.When using malloc function, which of the following should be done before using the allocated memory?
a) Initialize the memory using memset
b) Check if the allocation was successful
c) Deallocate the memory using free
d) Both b and c
Answer: d) Both b and c
Q8.What will happen if malloc fails to allocate memory in C?
a) It returns a NULL pointer
b) It terminates the program
c) It returns a random memory address
d) It returns a negative value
Answer: a) It returns a NULL pointer
Q9. How is memory alignment maintained in dynamically allocated memory in C?
a) By using sizeof operator
b) By explicitly aligning memory
c) By allocating memory in multiples of 4 bytes
d) By default
Answer: d) By default
Q10.Which memory allocation function in C allows resizing of memory blocks?
a) realloc
b) malloc
c) calloc
d) free
Answer: a) realloc
Q11.What is the alternative way of allocating memory in C besides malloc?
a) calloc
b) realloc
c) free
d) new
Answer: a) calloc
Q12.In C, how is memory deallocated if a dynamically allocated array is no longer needed?
a) Using the delete operator
b) Using the free function
c) Using realloc function
d) By assigning NULL to the pointer
Answer: b) Using the free function
Q13.What is the purpose of the sizeof operator in dynamically allocating memory in C?
a) To determine the size of the memory block to allocate
b) To check the alignment of memory
c) To get the memory address of an allocated block
d) To size the memory block to be released
Answer: a) To determine the size of the memory block to allocate
Q14.Which of the following statements is true about realloc function in C?
a) It can reduce the size of a memory block
b) It can only increase the size of a memory block
c) It cannot be used on NULL pointers
d) It is used for memory deallocation
Answer: a) It can reduce the size of a memory block
Q15.What happens if the realloc function fails to reallocate memory in C?
a) The original memory block remains unchanged
b) The program terminates
c) The original memory block is deallocated
d) NULL pointer is returned
Answer: a) The original memory block remains unchanged
Q16What is the purpose of the calloc function in C?
a) Allocates memory and initializes all bytes to zero
b) Allocates memory without initialization
c) Deallocates memory
d) Allocates memory and returns a random memory address
Answer: a) Allocates memory and initializes all bytes to zero
Q17.How can memory leaks be avoided in C while using dynamic memory allocation?
a) Always deallocate memory after use
b) Do not use dynamic memory allocation
c) Ignore memory leaks as they are harmless
d) Use realloc instead of malloc
Answer: a) Always deallocate memory after use
Q18. What will the following code snippet do in C?
int* ptr = (int*)malloc(5 * sizeof(int));
memset(ptr, 0, sizeof(int)*5);
a) Allocate memory for 5 integers and initialize them to zero
b) Allocate memory for 5 integers without initialization
c) Initialize an existing integer array to zero
d) Deallocate memory for 5 integers
Answer: a) Allocate memory for 5 integers and initialize them to zero
Q19.Which library needs to be included to use the malloc function in C?
a) <stdlib.h>
b) <stdio.h>
c) <math.h>
d) <memorygh>
Answer: a)
Q20.What is the purpose of performing a NULL check after malloc in C?
a) To verify if memory has been successfully allocated
b) To avoid memory leaks
c) To deallocate memory
d) To initialize the allocated memory
Answer: a) To verify if memory has been successfully allocated
Q21.How can memory fragmentation be reduced when using dynamic memory allocation in C?
a) By using realloc instead of malloc
b) By using calloc instead of malloc
c) By freeing memory blocks when they are no longer needed
d) By ignoring memory fragmentation
Answer: c) By freeing memory blocks when they are no longer needed
Q22.When using dynamic memory allocation in C, how can memory corruption be avoided?
a) By using the new operator instead of malloc
b) By initializing the memory after allocation
c) By carefully managing memory allocation and deallocation
d) By not using dynamic memory allocation
Answer: c) By carefully managing memory allocation and deallocation
Q23.Which of the following is a use case for realloc function in C?
a) To allocate a new memory block
b) To reallocate memory for resizing an array
c) To free memory after use
d) To avoid memory leaks
Answer: b) To reallocate memory for resizing an array
Q24.What is the difference between malloc and calloc functions in C?
a) Malloc initializes memory to zero, but calloc does not.
b) calloc allocates memory in multiples of the specified size
c) malloc allocates memory and returns a random memory address
d) calloc initializes memory to zero while malloc does not
Answer: d) calloc initializes memory to zero while malloc does not
Q25.Why should dynamic memory allocation be used sparingly in C programming?
a) It is faster and more efficient than static memory allocation
b) It can lead to memory leaks and fragmentation
c) It is easier to manage than static memory allocation
d) It allows for better memory utilization
Answer: b) It can lead to memory leaks and fragmentation
Q26.Which of the following statements is true about the free function in C?
a) It deallocates memory and sets the pointer to NULL
b) It initializes memory to zero
c) It can only be used on memory allocated by calloc function
d) It can only deallocate memory allocated by realloc function
Answer: a) It deallocates memory and sets the pointer to NULL
Q27.How can memory leaks be identified in C programs using dynamic memory allocation?
a) By running static code analysis tools
b) By manually reviewing the code
c) By using debuggers
d) All of the above
Answer: d) All of the above
Q28.What happens if the malloc function is called with a size of zero in C?
a) It allocates a memory block of zero size
b) It returns NULL pointer
c) It allocates a small amount of memory
d) It initializes memory to zero
Answer: b) It returns NULL pointer
Q29.What is the significance of casting the return value of malloc function in C?
a) It is necessary to avoid memory leaks
b) It is good practice but not mandatory
c) It is required to handle memory allocation errors
d) It is unnecessary as malloc returns a void pointer
Answer: d) It is unnecessary as malloc returns a void pointer
Q30.Which of the following functions should be used to allocate contiguous memory for array elements in C?
a) malloc
b) calloc
c) realloc
d) free
Answer: a) malloc
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