Question examples

Question 1

What information defines a UDP socket?
a. Source IP address
b. Source port number
c. Destination IP address
d. Destination port number

Answer 1

d. Destination port number (UDP is connectionless; only the destination port matters)

Question 2

What do processes exchange when communicating in different end systems?
a. Memory
b. Files
c. Messages
d. Protocols

Answer 2

c. Messages (Processes communicate via messages, e.g. HTTP requests/responses)

Question 3

Which of the following is(are) TCP/IP layer(s)?
a. Network
b. Session
c. Application
d. Transport

Answer 3

a,c,d

Question 4

Which command deletes a directory and all its contents?
a. mkdir
b. rm -r
c. cp -r
d. rmdir

Answer 4

b. rm -r (Recursive delete; rmdir only remove empty directories)

Question 5

‘What is the server’s response to the HTTP GET request?
a. 200 OK
b. 404 Not Found
c. 401 Unauthorised
d. 403 Forbidden

Answer 5

a. 200 OK (Default success response for valid GET requests)

Question 6

What is it called when processes wait indefinitely for an event caused by another waiting process?
a. Starvation
b. Priority inversion
c. Deadlock
d. Blocking

Answer 6

c. Deadlock (Circular dependency; no progress possible)

Question 7

Which of the following are program threats?
a. Viruses
b. Worms
c. Port scanning
d. Trojan horse

Answer 7

a,b,d

Question 8

Which protocol provides connection-oriented communication?
a. UDP
b. TCP
c. ICMP
d. HTTP

Answer 8

b. TCP (TCP is reliable/connection-oriented; UDP is connectionless)

Question 9

What ensures only one process executes its critical section at a time?
a. Deadlock
b. Semaphore
c. Starvation
d. Fragmentation

Answer 9

b. Semaphore (Sync tool to enforce mutual exclusion)

Question 10

Which is a key difference between IPv4 and IPv6?
a. IPv6 uses shorter addresses
b. IPv6 eliminates fragmentation
c. IPv4 supports more devices
d. IPv6 removes checksums

Answer 10

b. IPv6 eliminates fragmentation (handled by endpoints, not routers)

Question 11

Which is NOT a Java thread state?
a. NEW
b. RUNNABLE
c. SLEEPABLE
d. TERMINATED

Answer 11

c. SLEEPING

Question 12

Which uses the same key for encryption and decryption?
a. RSA
b. AES
c. Diffie-Hellman
d. PGP

Answer 12

b. AES (Symmetric encryption; others are asymmetric)

Question 13

What sync mechanism solves the producer-consumer problem?
a. Mutex
b. Monitor
c. Both a and b
d. Neither

Answer 13

c. Both a and b (Mutex locks, Monitors can enforce buffer access rules)

Question 14

Discuss how two processes communicate over a network. Include sockets, ports, IP address and transport services

Answer 14

1. Sockets: Endpoints for communication (IP + port)
2. Ports: Identify processes (e.g. HTTP = port 80)
3. IP Addresses: Locate hosts (e.g. 192.168.1.1)
4. Transport Services: TCP (reliable), UDP (unreliable)
5. E.g. Web browser (client) uses TCP to connect to a server’s socket (IP: port)

Question 15

What are system programs? Differentiate from applications and discuss 5 categories.

Answer 15

1. Definition: Software managing hardware/resources (e.g., OS utilities)
2. vs. Application: System programs- OS level (e.g. disk formatter), Applications- User level (e.g. web browser)
3. Categories: File management (ls, cp), Process control (kill, ps), System monitoring (top), Programming tools (compilers), Communication (SSH, pipes)

Question 16

Discuss 3 types of program threats with examples

Answer 16

1. Virus: Attaches to files (e.g., macro virus in Word docs).
2. Worm: Self-replicating (e.g., Morris Worm, 1988).
3. Trojan Horse: Disguised malware (e.g., fake game installer).