GATE CS question library

Let $L$ be a language and $\bar{L}$ be its complement. Which one of the following is NOT a viable possibility?

A canonical set of items is given below $S \to L .> R$ $Q \to R.$ On input symbol $<$ the set has

Assume that there are $3$ page frames which are initially empty. If the page reference string is $\text{1, 2, 3, 4, 2, 1, 5, 3, 2, 4, 6}$ the number of page faults using the optimal replacement policy is__________.

Consider the following set of processes that need to be scheduled on a single CPU. All the times are given in milliseconds. …

An operating system uses the Banker's algorithm for deadlock avoidance when managing the allocation of three resource types $X, Y,$ and $Z$ to three processes $P0, P1,$ and $P2.$ The table given below presents the current system state. Here, the Allocation matrix shows the current number of resources of each type allocated to each process and the Max …

Given the following two statements: S1: Every table with two single-valued attributes is in $\text{1NF, 2NF, 3NF}$ and $\text{BCNF}.$ S2: $AB \to C, D \to E, E \to C$ is a minimal cover for the set of functional dependencies $AB \to C, D \to E, AB \to E, E \to C$. Which one of the following is CORRECT?

Consider the following four schedules due to three transactions (indicated by the subscript) using read and write on a data item x, denoted by $r(x)$ and $w(x)$ respectively. Which one of them is conflict serializable?

Consider a selective repeat sliding window protocol that uses a frame size of $1$ $\text{KB}$ to send data on a $1.5$ $\text{Mbps}$ link with a one-way latency of $50$ $\text{msec}$. To achieve a link utilization of $60\%$, the minimum number of bits required to represent the sequence number field is ________.

Let the size of congestion window of a TCP connection be $32$ KB when a timeout occurs. The round trip time of the connection is $100$ msec and the maximum segment size used is $2$ KB. The time taken (in msec) by the TCP connection to get back to $32$ KB congestion window is _________.

Consider a token ring network with a length of 2 km having 10 stations including a monitoring station. The propagation speed of the signal is $2 \times10^8m/s$ and the token transmission time is ignored. If each station is allowed to hold the token for $2 µsec$, the minimum time for which the monitoring station should wait (in $µsec$) before assuming …

Identify the correct order in which the following actions take place in an interaction between a web browser and a web server. The web browser requests a webpage using HTTP. The web browser establishes a TCP connection with the web server. The web server sends the requested webpage using HTTP. The web browser resolves the domain name using DNS.

Which of the following are used to generate a message digest by the network security protocols? RSA SHA-$1$ DES MD5

Given the following statements: S1: A foreign key declaration can always be replaced by an equivalent check assertion in SQL. S2: Given the table $R(a,b,c)$ where $a$ and $b$ together form the primary key, the following is a valid table definition. CREATE TABLE S ( a INTEGER, d INTEGER, e INTEGER, PRIMARY KEY (d), FOREIGN KEY (a) references R) Which …

Consider the following three statements about link state and distance vector routing protocols, for a large network with $500$ network nodes and $4000$ links. [S1]: The computational overhead in link state protocols is higher than in distance vector protocols. [S2]: A distance vector protocol (with split horizon) avoids persistent routing loops, but not …

Consider the relation scheme $R = (E, F, G, H, I, J, K, L, M, N)$ and the set of functional dependencies $$\left\{ \{E, F \} \to \{G\}, \{F\} \to \{I, J\}, \{E, H\} \to \{K, L\}, \\ \{K\} \to \{M\}, \{L\} \to \{N\}\right\}$$ on $R$. What is the key for $R$?

Which one of the following is FALSE?

Suppose a disk has $201$ cylinders, numbered from $0$ to $200$. At some time the disk arm is at cylinder $100$, and there is a queue of disk access requests for cylinders $30, 85, 90, 100, 105, 110, 135$ and $145$. If Shortest-Seek Time First (SSTF) is being used for scheduling the disk access, the request for cylinder $90$ is serviced after …

Match the following: 1) Waterfall model a) Specifications can be developed incrementally 2) Evolutionary model b) Requirements compromises are inevitable 3) Component-based software engineering c) Explicit recognition of risk 4) Spiral development d) Inflexible partitioning of the project into stages

Consider the finite automaton in the following figure: What is the set of reachable states for the input string $0011$?

Which one of the following is TRUE?