UGC NET Computer Science 2024 Previous Year Questions (PYQs) – Page 2 of 20

Steps in page replacement:

No frame is free → D

Find a frame to replace → A

Free that frame → E

Update the page table → B

Use the freed frame for the new page → C

Typical DBMS query processing steps:

Scanning, parsing and validating → C

Query optimizer → A

Query code generator → D

Runtime database processor → B

Correct order:

C → A → D → B

Insert words sequentially into BST.

banana → root

peach → right of banana

apple → left of banana

pear → right of peach

coconut → left of peach

mango → right of coconut

papaya → right of mango

Longest path:

banana → peach → coconut → mango → papaya

Number of edges = 4

Verification → Quality Assurance → IV

Validation → Quality Control → III

Internal logic exercise → White box testing → I

Software requirement exercise → Black box testing → II

Matching:

A → IV

B → III

C → I

D → II

Memory required:

$2048 \times 8$

Each chip:

$128 \times 4$

First match word size:

$8 / 4 = 2$ chips per word.

Now match number of words:

$2048 / 128 = 16$

Total chips:

$16 \times 2 = 32$

A: False when $r=1, p=0$ → Not tautology

B: False when $p=1, r=0$ → Not tautology

C:

$\sim p \rightarrow (p \rightarrow r)$

Always true → Tautology

D:

$(p \land r) \rightarrow (p \rightarrow r)$

Always true → Tautology

E:

$\sim(p \rightarrow r) \rightarrow p$

Always true → Tautology

Thus tautologies:

C, D, E

Sequential circuits depend on previous state (memory).

• Flip-flop → sequential circuit

• Counter → sequential circuit

Multiplexer, Decoder and Adder are combinational circuits.

Union → User defined data type → IV

Function → Subroutine → III

Interactive Environment → Virtual Reality → I

Output device → Shadow mask → II

Matching:

A → IV

B → III

C → I

D → II

A Perceptron is a single-layer feed-forward neural network used for linear classification.

Backtracking → Predictive parsing may require backtracking → III

Infinite languages with matching numbers → handled using Automata → I

Canonical LR parser → requires large number of states → IV

Post Correspondence Problem → Undecidable problem → II

Matching:

A → III

B → I

C → IV

D → II