Nptel Social Networks Week 6 Assignment Answers(Jan-Apr 2025)
Que. 1 Which of the following best describes a web graph? a) A graph with nodes representing users and edges representing their social connections b) A directed graph where nodes represent web pages and edges represent hyperlinks c) A graph representing data transmission in a network d) An undirected graph with nodes representing servers and edges representing data flows
Que. 2 What is the main challenge in analyzing web graphs at a large scale? a) Ensuring the graph remains connected b) Handling the scale-free and sparse nature of the graph c) Maintaining an equal degree distribution for all nodes d) Converting directed graphs into undirected graphs
Que. 3 In the equal coin distribution problem, the goal is typically to: a) Minimize the number of coins redistributed b) Maximize the sum of coins in the system c) Ensure every individual has the same number of coins after redistribution d) Distribute coins randomly among all individuals
Que. 4 What condition must hold true for equal coin distribution to be possible in a system of N people with C total coins? a) C must be a multiple of N b) C must be an even number c) The graph must be fully connected d) N must be a prime number
Que. 5 In random coin dropping simulations, which of the following distributions is often observed in the final system state? a) Gaussian distribution b) Uniform distribution c) Power-law distribution d) Exponential distribution
Que. 6 What does random coin dropping often illustrate in terms of network behavior? a) Centralized control of resources b) Emergence of inequality in distributions over time c) Uniform redistribution of resources d) Cyclic patterns in resource allocation
Que. 7 In Google’s PageRank algorithm, a node’s rank is determined by: a) Its in-degree only b) Its out-degree only c) The ranks of its incoming neighbors and their out-degrees d) The ranks of its outgoing neighbors and their in-degrees
Que. 8 In the point distribution method for PageRank, what happens when a node distributes its rank points to its neighbors? a) It retains half of its points and distributes the rest equally b) It loses all its points in the next iteration c) It distributes all its points equally to its neighbors d) It distributes points based on the degree of neighbors
Que. 9 How does the random walk model in PageRank deal with “dangling nodes” (nodes with no outgoing edges)? a) Dangling nodes are removed from the graph b) A damping factor redistributes their rank randomly c) Their rank is equally distributed among all other nodes d) Their rank remains constant in the system
Que. 10 Which of the following best describes the difference between degree rank and PageRank in a web graph? a) Degree rank considers only the number of edges, while PageRank considers the importance of neighbors b) Degree rank is computed iteratively, while PageRank is calculated directly c) PageRank uses only in-degrees, while degree rank uses both in-degrees and out-degrees d) Degree rank is always higher than PageRank for nodes with high connectivity
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q1. Which of the following is the most efficient way of obtaining the big web graph containing billions of nodes? Breadth First Search Depth First Search Linear search Binary search Random walk
Answer: Random walk
Q2. What is the problem in link analysis that teleportation solves? differentiate an important website from all websites It prevents web crawlers from getting stuck in infinite loops It helps web crawler to visit all nodes during analysis none of the above
Answer: It helps web crawler to visit all nodes during analysis
Q3. Choose the correct option corresponding to the gold coins’ distribution game. The game might not converge. The game converges even with people having an equal or unequal number of gold coins. The game converges only when people have an unequal number of gold coins. The game converges only when people have an equal number of gold coins.
Answer: The game converges even with people having an equal or unequal number of gold coins.
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q4. Consider algorithm 1 to be equal sharing coin distribution game and algorithm 2 to be random dropping coin distribution game. Which of the following is true? Algorithm 1 ranks the nodes in ascending order of their importance while algorithm 2 ranks the nodes in descending order of importance. Both the algorithms rank the nodes in descending order of their importance but give different results. Algorithm 1 ranks the nodes in descending order of their importance while algorithm 2 ranks the nodes in ascending order of importance. Both the algorithms rank the nodes in descending order of their importance and give same result.
Answer: Both the algorithms rank the nodes in descending order of their importance and give same result.
Q5. Given a complete network having 4 nodes. We take a random walk of length 1 million on this network. Every time we arrive on a node, we gift it a gold coin. The approximate number of gold coins each node collects at the end of this experiment is 1 million each Two nodes collect half of a million gold coins and two nodes remain empty handed Quarter a million each Since the experiment is probabilistic, nothing can be said
Answer: Quarter a million each
Q6. Which of the following is not possible in the gold coin distribution game? Total number of coins circulating in the system decreases One node ends up collecting all the gold coins One node ends up getting no gold coin Total number of coins in the system increases
Answer: Total number of coins in the system increases
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q7. Choose the correct statement with respect to the pagerank matrix. Pagerank matrix is symmetric Sum of elements in each column is 1. Pagerank matrix is same as the adjacency matrix of a graph. Sum of elements in each row is 1.
Answer: Sum of elements in each column is 1.
Q8. A gold coin distribution game is played on the following network. When the game converges, Yahoo, Amazon and M’soft, each collects one third of the coins M’soft collects all the coins Yahoo and M’soft together gets all the coins and Amazon gets none All the coins are lost
Answer: M’soft collects all the coins
Q9. In the graph G shown in following figure, assume that the current pagerank values of A, B and C are 0.3, 0.3 and 0.4 respectively. What will be their pagerank values after one iteration? A : 0.4,B : 0.3,C : 0.3 A : 0.4,B : 0.4,C : 0.2 A : 0.3,B : 0.3,C : 0.4 A : 0.3,B : 0.4,C : 0.3
Answer: A : 0.4,B : 0.3,C : 0.3
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q10. Consider the graph shown in Figure 12. The number written in each circle represents the number of gold coins possessed by the corresponding node. Choose the number of gold coins every node has in the next iteration, according to the equal sharing gold coins’ game. A: 20, B: 40, C: 30, D: 30 A: 30, B: 40, C: 40, D: 40 A: 30, B: 40, C: 30, D: 30 A: 20, B: 40, C: 40, D: 30
Answer: A: 30, B: 40, C: 30, D: 30
These are Nptel Social Networks Week 6 Assignment 6 Answers
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q1. Which of the following is valid about characteristics of a web graph? a. Directed and cyclic b. Directed and acyclic c. Directed and cyclic/acyclic d. Undirected and cyclic e. Undirected and acyclic f. Undirected and cyclic/acyclic
Answer: c. Directed and cyclic/acyclic
Q2. Pick out the most efficient technique to obtain the web graph containing a huge number of nodes. a. Breadth first search b. Depth first search c. Random walk d. Both A and B
Answer: c. Random walk
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q3. Consider the graph shown in the following Figure. The number written in each circle represents the number of gold coins possessed by the corresponding node(20, 30, 20, 30). Choose the number of gold coins every node has in the next iteration, according to the equal sharing gold ‘coins’ game.
a. 20, 30, 20, 60 b. 30, 40, 30, 30 c. 20, 30, 20, 30 d. 20, 20, 20, 20
Answer: c. 20, 30, 20, 30
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q4. Identify the type of nodes that can cause a challenge in the Random walk coin distribution technique. a. indegree > outdegree b. outdegree > indegree c. zero outdegree d. high outdegree
Answer: c. zero outdegree
Q5. Consider algorithm 1 to be equal sharing coin distribution game and algorithm 2 to be random dropping coin distribution game. Which of the following is true? a. Algorithm 1 converges but Algorithm 2 does not b. Algorithm 2 converges but Algorithm 1 does not c. Both algorithms converge d. None of them converges
Answer: c. Both algorithms converge
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q6. In the graph shown in the following figure, assume that the current pagerank values of A, B and C are 0.4, 0.2 and 0.4 respectively. What will be their pagerank values after one iteration?
a. A : 0.4,B : 0.4,C : 0.4 b. A : 0.2,B : 0.4,C : 0.4 c. A : 0.4,B : 0.2,C : 0.4 d. A : 0.4,B : 0.4,C : 0.2
Answer: d. A : 0.4,B : 0.4,C : 0.2
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q7. In a random graph with n nodes, the number of nodes to be traversed in order to to visit all nodes in a random walk as observed in the experiment is approximately a. log n b. n log n c. n2 d. 2n
Answer: b. n log n
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q8. Which of the following is true for Teleportation? Statement I – Choosing a node uniformly at random in a graph Statement II – Choosing the highest degree node in the graph a. I only b. II only c. Both d. None
Answer: a. I only
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q9. A web graph is a/an a. Directed graph b. Undirected graph c. Complete graph d. Bipartite graph
Answer: a. Directed graph
These are Nptel Social Networks Week 6 Assignment 6 Answers
Q10. If nx represents networkx library then, for a graph G, what does nx.pagerank(G) returns? a. List of web pages that are top 10 priority b. List of page rank values c. Dictionary where keys are nodes and values are Page ranks d. Dictionary where keys are Page ranks and values are nodes
Answer: c. Dictionary where keys are nodes and values are Page ranks
These are Nptel Social Networks Week 6 Assignment 6 Answers
