Consider a process executing on an operating system that uses demand paging. The average 

time for a memory access in the system is M units if the corresponding memory page is 

available in memory and D units if the memory access causes a page fault. It has been 

experimentally measured that the average time taken for a memory access in the process is 

X units.

Which one of the following is the correct expression for the page fault. It has been 

experimentally measured that the average time taken for a memory access in the process is 

X units.

Which one of the following is the correct expression for the page fault rate experienced by the 

process?

A.

(D M / X M − − ) ( )

B.

(X M / D M − − ) ( )

C.

(D X / D M − − ) ( )

D.

(X M / D X − − ) ( )

2. Consider a system with 3 processes that share 4 instances of the same resource type. Each 

process can request a maximum of K instances. Resource instances can be requested and 

released only one at a time. The largest value of K that will always avoid deadlock is

3. Consider the following four relational schemas. For each schema, all non-trivial functional 

dependencies are listed. The underlined attributes are the respective primary keys. 

Schema I : Registration (rollno, courses)

Field 'courses' is a set-valued attribute containing the set of courses a student 

has registered for.

rollno → courses

Schema II : Registration (rollno, courseid, 

email)

Non-trivial functional dependencies: 

rollno, courseid → email

email → rollno

Schema III : Registration (rollno, courseid, 

marks, grade)

Non-trivial functional dependencies: 

rollno, courseid → marks, 

grade

marks → grade

Schema IV : Registration (rollno, courseid, 

credit)

Non-trivial functional dependencies: 

rollno, courseid → credit 

courseid → credit

Which one of the relational schemas above is in 3NF but not in BCNF?

A. Schema I B. Schema II

C. Schema III D. Schema IV

4. Consider the following problems L(G) denotes the language generated by a grammar G. L(M) 

denotes the language accepted by a machine M.

I. For an unrestricted grammar G and a string w, where 

w 

L(G).

II. Given a Turing Machine M, whether L(M) is regular.

III. Given two grammars 

G1

and 

G2

whether 

L G L G . ( 1 2 ) = ( )

IV. Given an NFAN, whether there is a deterministic PDA P such that N and P accept the same 

language.

Which one of the following statements is correct?

A. Only I and II are undecidable

B. Only III is undecidable

C. Only II and IV are undecidable 

D. Only I, II and III are undecidable