OPERATING SYSTEM MCQS PART 04

OPERATING SYSTEM MCQS PART 04

1. A parser which is a variant of top-down parsing without backtracking is
(A) Recursive Descend.         
(B) Operator Precedence.
(C) LL(1) parser.                     
(D) LALR Parser.
Ans: (A)

2.The expansion of nested macro calls follows
(A) FIFO rule.       
(B) LIFO rule.      
(C) LILO rule.      
(D) priority rule.
Ans: (B)

3. In a two-pass assembler, the task of the Pass II is to
(A) separate the symbol, mnemonic opcode and operand fields.
(B) build the symbol table.
(C) construct intermediate code.
(D) synthesize the target program.
Ans: (D)

4. A linker program
(A) places the program in the memory for the purpose of execution.
(B) relocates the program to execute from the specific memory area allocated to it.
(C) links the program with other programs needed for its execution.
(D) interfaces the program with the entities generating its input data.
Ans: (C)
5. Which scheduling policy is most suitable for a time-shared operating system
(A) Shortest-job First.                   
(B) Elevator.
(C) Round-Robin.                         
(D) First-Come-First-Serve.
Ans: (C)
6. A critical section is a program segment
(A) which should run in a certain specified amount of time.
(B) which avoids deadlocks.
(C) where shared resources are accessed.
(D) which must be enclosed by a pair of semaphore operations, P and V.
Ans: (C)
7. An operating system contains 3 user processes each requiring 2 units of resource R. The minimum number of units of R such that no deadlocks will ever arise is
(A) 4.           
(B) 3.         
(C) 5.                   
(D) 6.
Ans: (A)

8. Locality of reference implies that the page reference being made by a process
(A) will always be to the page used in the previous page reference.
(B) is likely to be the one of the pages used in the last few page references.
(C) will always be to one of the pages existing in memory.
(D) will always lead to a page fault.
Ans: (B)

9. Which of these is not a part of Synthesis phase
(A) Obtain machine code corresponding to the mnemonic from the Mnemonics table
(B) Obtain address of a memory operand from the symbol table
(C) Perform LC processing
(D) Synthesize a machine instruction or the machine form of a constant
Ans: (C)
10. The syntax of the assembler directive EQU is
(A) EQU         
(B) EQU              
(C) EQU             
(D) None of the above
Ans: (B)