GATE 2020 Computer Science and IT Question Paper with answer

Consider the following statements:
I. Daisy chain uses priorities for selecting devices.
II. when there is vectored interrupt then polling is used for getting address.
III. Polling processor uses periodically checks status bit to check if interrupt needs to process.
IV. DMA access processor and DMA controller can simultaneously access at the same time.

Consider to semaphore a and b whose initial values are 1 and 0 respectively. Count is the shared variable which is not used in code section P;

Code section P

Wait (a);

 If (count ==n); signal(b);

signal(a); wait(b); signal(b);

Code section Q 

What does this code achieve?

For a database we are using B+ tree indexing with 1 million records in the database, each record fits in one block. Block size is 8 KB and search key size is 12 bytes, block pointer size is 8 bytes. Minimum
number of block access required for database, the record is ___

Which of the following many-to-one rules of weak-entity are set in ER diagram ?

TCP connection maximum segment size = 2 KB is starting at t = 0 and threshold are 32 KB and calculates sender window size at (+60 ms) where (RTT – 6 ms) given 50 KB as the maximum segment.