Objective Questions(121-128)

121. Which combination of the following features will suffice to characterize an OS as a multi-programmed OS ? (A)More than one program may be loaded into main memory at the same time for execution.

(B) If a program waits for certain events such as I/O, another program is immediately scheduled for execution.

(C) If the execution of a program terminates, another program is immediately scheduled for execution.
(A) A (B) A and B
(C) A and C (D) A, B and C

122. Consider a machine with 64 MB physical memory and a 32-bit virtual
address space. If the page size is 4 KB, what is the approximate size
of the page table ?
(A) 16 MB
(B) 8 MB
(C) 2 MB
(D) 24 MB

Size of main memory = 64 MB
Size of virtual memory = 2^32 Bit

No. of pages = 2^32/2^12

= 2^20 pages
Required 1 M enteries.
But each entry has both a virtual address & corresponding physical
address.
Total bits in each entry = 32 + 26 (Physical)
= 58
= 58/8 = 8 Bytes.

So total memory = 8 * 1 MB
= 8 MB

123. An Application Program Interface (API) language is used for

(A) Network Management

(B) Graphical user Interface

(C) Relational Interface in Data Base Management

(D) Database Management System

124. The portion of Windows 2000 operating
system which is not portable is
(A) processor management
(B) user interface
(C) device management
(D) virtual memory management

125. which operator is used for making range checks in queries..?
a. like
b. in
c. between
d. to

126. Consider a set of n tasks with known runtimes r1, r2, ........rn to be
run on a uniprocessor machine. Which of the following processor
scheduling algorithms will result in the maximum throughput ?
(A) Round-Robin
(B) Shortest-Job-First
(C) Highest-Response-Ratio-Next
(D) First-come-First-Served

Here the running times r1 ....rn are already known, single processor
system. In this scenario, throughput i.e. CPU is maximum utilized in
shortest job first scheduling. B is correct

127.page shift keying method is use to modulate digital signal at 9600 bps using 16 level. find the line signals and speed ?
a) 2400 bauds
b) 1200 bauds
c) 4800 bauds
d) 9600 bauds

9600/4 bauds

because in 16PSK, 4 bits can be represented in a single signal so baudrate=bitrate/4

 

128. If there are 10 nodes on a token ring
with a message transmit time of 15
milliseconds, and a token passing
time of 5 milliseconds, what is the
maximum time a token ring station
must wait to transmit a message ?
(A) 20 milliseconds
(B) 15 milliseconds
(C) 180 milliseconds
(D) 200 milliseconds