1. : What is a binary tree?
(A) A tree with at most 2 children for each node
(B) A tree where each node has exactly 2 children
(C) A tree with an arbitrary number of children for each node
(D) A tree where nodes are arranged in a binary search order
2. : Which of the following statements is true about binary trees?
(A) Each node has exactly one child
(B) Each node has at most two children
(C) Each node has an unlimited number of children
(D) Each node has exactly three children
3. : What is a binary search tree (BST)?
(A) A binary tree where the left child is greater than the parent and the right child is less than the parent
(B) A binary tree where the left child is less than the parent and the right child is greater than the parent
(C) A binary tree where the left child is equal to the parent and the right child is not equal to the parent
(D) A binary tree where the left child is less than or equal to the parent and the right child is greater than or equal to the parent
4. : What is the minimum number of nodes in a binary tree of height 3?
(A) 4
(B) 5
(C) 6
(D) 7
5. : What is the maximum number of nodes in a binary tree of height 4?
(A) 8
(B) 15
(C) 16
(D) 31
6. : Which traversal visits the nodes in the order: left subtree, root, right subtree?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
7. : In a binary tree, if a node has no children, it is called a:
(A) Leaf node
(B) Root node
(C) Internal node
(D) Sibling node
8. : Which traversal visits the root node first, then the left subtree, and finally the right subtree?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
9. : Which of the following operations can be efficiently implemented using a binary search tree?
(A) Finding the maximum element
(B) Finding the minimum element
(C) Finding the median element
(D) Finding the nth smallest element
10. : Which traversal visits the nodes in the order: left subtree, right subtree, root?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
11. : What is the time complexity of searching for an element in a balanced binary search tree?
(A) O(1)
(B) O(log n)
(C) O(n)
(D) O(n log n)
12. : Which of the following operations requires the worst-case time complexity in a binary search tree?
(A) Insertion
(B) Deletion
(C) Searching
(D) Traversal
13. : What is the height of a binary tree with only one node?
(A) 0
(B) 1
(C) 2
(D) Undefined
14. : Which traversal is used to create a copy of a binary tree?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
15. : In a binary tree, what is the maximum number of nodes at level 3?
(A) 4
(B) 7
(C) 8
(D) 15
16. : Which traversal can be used to evaluate postfix expressions?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
17. : Which traversal is commonly used to sort elements in a binary search tree in ascending order?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order
18. : Which of the following is NOT a valid binary tree traversal?
(A) Left-root-right
(B) Root-left-right
(C) Right-root-left
(D) Left-right-root
19. : What is the maximum number of leaf nodes in a binary tree with 15 nodes?
(A) 7
(B) 8
(C) 15
(D) 16
20. : Which traversal visits all the levels of nodes in order from top to bottom, left to right?
(A) Preorder
(B) Inorder
(C) Postorder
(D) Level order