Systems Programming Multiple choice Questions and Answers-UGC NET computer science question paper

61.	At the end of parsing,
a.	tokens are identified.
b.	set of instructions are identified.
c.	the syntactic groups are identified.
d.	machine instructions are identified.

Answer: (a).tokens are identified.

62.	Dead-code elimination in machine code optimization refers to:
a.	removal of all labels.
b.	removal of values that never get used.
c.	removal of function which are not involved.
d.	removal of a module after its use.

Answer: (b).removal of values that never get used.

63.	A parse tree is an annotated parse tree if:
a.	it shows attribute values at each node.
b.	there are no inherited attributes.
c.	it has synthesized nodes as terminal nodes.
d.	every non-terminal nodes is an inherited attribute.

Answer: (a).it shows attribute values at each node.

64.	In a two pass compiler, during the first pass:
a.	user defined address symbols are correlated with their binary equivalent
b.	the syntax of the statement is checked and mistakes, if any, are listed
c.	object program is generated
d.	semantic of the source program is elucidated

Answer: (a).user defined address symbols are correlated with their binary equivalent

65.	A single instruction in an assembly language program contains:
a.	one micro operation
b.	one macro operation
c.	one instruction to be completed in a single pulse
d.	one machine code instruction

Answer: (b).one macro operation

66.	Absolute loader demands that the programmer needs to know the:
a.	start address of the available main memory
b.	total size of the program
c.	actual address of the data location
d.	absolute values of the operands used

Answer: (a).start address of the available main memory

67.	Top-down parsers are predictive parsers, because:
a.	next tokens are predicted
b.	length of the parse tree is predicted before hand
c.	lowest node in the parse tree is predicted
d.	next lower level of the parse tree is predicted

Answer: (a).next tokens are predicted

68.	In the context of compiler design, “reduction in strength” refers to:
a.	code optimization obtained by the use of cheaper machine instructions
b.	reduction in accuracy of the output
c.	reduction in the range of values of input variables
d.	reduction in efficiency of the program

Answer: (a).code optimization obtained by the use of cheaper machine instructions

69.	How many states can a process be in?
a.	2
b.	3
c.	4
d.	5

Answer: (d).5

70.	The parsing technique that avoids back tracking is:
a.	Top-down parsing
b.	Recursive-descent parsing
c.	Predictive
d.	Syntax tree

Answer: (c).Predictive