# B-Tree Multiple choice Questions and Answers (MCQs)

## B-Tree Multiple choice Questions and Answers (MCQs)

 Question 1
Which of the following is the most widely used external memory data structure?
 A AVL tree B B-tree C Red-black tree D Both AVL tree and Red-black tree
Question 1 Explanation:
In external memory, the data is transferred in form of blocks. These blocks have data valued and pointers. And B-tree can hold both the data values and pointers. So B-tree is used as an external memory data structure.

 Question 2
B-tree of order n is a order-n multiway tree in which each non-root node contains .....
 A at most (n - 1)/2 keys B exact (n - 1)/2 keys C at least 2n keys D at least (n - 1)/2 keys
Question 2 Explanation:
A non-root node in a B-tree of order n contains at least (n - 1)/2 keys. And contains a maximum of (n - 1) keys and n sons.

 Question 3
A B-tree of order 4 and of height 3 will have a maximum of ..... keys.
 A 255 B 63 C 127 D 188
Question 3 Explanation:
A B-tree of order m of height h will have the maximum number of keys when all nodes are completely filled. So, the B-tree will have n = ( mh+1 - 1) keys in this situation. So, required number of maximum keys = 43+1 - 1 = 256 - 1 = 255.

 Question 4
Five node splitting operations occurred when an entry is inserted into a B-tree. Then how many nodes are written?
 A 14 B 7 C 11 D 5