Computer Architecture Solved MCQs-Part 2

Usually ,in MSDOS ,the primary hard disk drives has the drive letter_______ A B C D       ____________________________________...

Usually ,in MSDOS ,the primary hard disk drives has the drive letter_______ A B C D       _____________________________________________________________________________________

P : “Program is a step by step execution of the instructions”. Given P, which of the following is true ? Program is a subset of an instruction set. Program is a sequence of a subset of an instruction set. Program is a partially ordered set of an instruction set. All of the above       _____________________________________________________________________________________

The most relevant addressing mode to write position independent code  Direct mode Indirect mode Relative mode Indexed mode       _____________________________________________________________________________________

An interface that provides a method for transferring binary information between internal storage and external devices is called  I/O interface Input interface Output interface I/O bus       _____________________________________________________________________________________

An interface that provides I/O transfer of data directly to and form the memory unit and peripheral is termed as  DDA Serial interface BR DMA       _____________________________________________________________________________________

In magnetic disk data organized on the plotter in a concentric sets or rings called Sector Track Head Block       _____________________________________________________________________________________

In which addressing mode the operand is given explicitly in the instruction Absolute Immediate Indirect Direct       _____________________________________________________________________________________

The instruction: MOV CL, [BX] [DI] + 8 represents the _____ addressing mode. Based Relative Based Indexed Indexed Relative Register Indexed       _____________________________________________________________________________________

A basic instruction that can be interpreted by computer generally has  An operand and an address A decoder and an accumulator Sequence register and decoder An address and decoder       _____________________________________________________________________________________

The two types of main memory are  Primary and secondary Random and sequential ROM and RAM Central and peripheral       _____________________________________________________________________________________

A hardware unit which is used to monitor computer processing is Console Dot matrix printer Mouse ROM       _____________________________________________________________________________________

On receiving an interrupt from an I/O device, the CPU halts for predetermined time branches off to the interrupt service routine after completion of the current instruction branches off to the interrupt service routine immediately hands over control of address bus and data bus to the interrupting device       _____________________________________________________________________________________

ADC Add to Accumulator using carry Flag Add to Accumulator Add Immediate data to Accumulator Add Immediate data to Accumulator Using carry       _____________________________________________________________________________________

The concept of pipelining is most effective in improving performance if the tasks being performed in different stages Require different amount of time Require about the same amount of time Require different amount of time with time difference between any two tasks being same Require different amount with time difference between any two tasks being different       _____________________________________________________________________________________

Performance of a pipelined processor suffers if  The pipeline stages have different delays Consecutive instructions are dependent on each other The pipeline stages share hardware resources All of these       _____________________________________________________________________________________

In a k-way set associative cache, the cache is divided into v sets, each of which consists of k lines. The lines of a set are placed in sequence one after another. The lines in set s are sequenced before the lines in set (s+1). The main memory blocks are numbered 0 onward. The main memory block numbered j must be mapped to any one of the cache lines from ( j mod v)*k to ( j mod v)*k + (k -1) ( j mod v) to ( j mod v) + (k -1) ( j mod k) to ( j mod k) + (v -1) ( j mod k)* v to ( j mod k)* v + (v -1)       _____________________________________________________________________________________

For a memory system ,the cycle time is  Same as the access time Longer than the access time Shorter than the access time Submultiple of the access time       _____________________________________________________________________________________

Secondary storage device which uses a delivery grooveless surface and is encoded by the laser beam in the form of microscopic pits is called Laser disk Compact disk Photo disk Video disk       _____________________________________________________________________________________

The addressing mode used in the instruction PUSH B is Direct Register Register indirect Immediate       _____________________________________________________________________________________

The idea of cache memory is based on The property of locality of reference The heuristic 90-10 rule The fact that only a small portion of a program is referenced relatively frequently All of these       _____________________________________________________________________________________

Where does a computer add and compare data ? Hard disk Floppy disk CPU chip Memory chip       _____________________________________________________________________________________

The speed up of a pipeline processing over an equivalent non-pipeline processing is defined by the ratio : A B C D       _____________________________________________________________________________________

The register used as a working area in CPU is  Program counter Instruction register Instruction decoder Accumulator       _____________________________________________________________________________________

The ALU of a microprocessor performs operations on 8 bit two complement operands. What happens when the operation 7A16-A216 is performed? Result = D816 , overflow and negative flags set Result = D816 , negative flags set Result = D816 ,no flags set Result = D816 , overflow flags set       _____________________________________________________________________________________

An interrupt can be temporarily ignored by the counter is called  Vector interrupt Non maskable interrupt Maskable interrupt Low priority interrupt       _____________________________________________________________________________________

A CPU generally handles an interrupt by executing an interrupt service routine as soon as an interrupt is raised by checking the interrupt register at the end of fetch cycle by checking the interrupt register after finishing the executing the current instruction by checking the interrupt register at fixed time intervals       _____________________________________________________________________________________

A single instruction to clear lower 4 bits of the accumulator in 8085 assembly language is  XRI OF H A NI OH X RI FOH ANI OF H       _____________________________________________________________________________________

Which out of the following is not an alternative name for primary memory?  Main memory Primary memory Internal storage Mass storage       _____________________________________________________________________________________

Which of the following is a sequential access device Hard disk Optical disk Tape Flash memory       _____________________________________________________________________________________

The ALU of a computer normally contains a number of high speed storage elements called  Semi conductor Register Hard disk Magnetic disk       _____________________________________________________________________________________

The control unit of computer Performs ALU operations on the data Controls the operation of the output devices Is a device for manually operating the computer Direct the other unit of computers       _____________________________________________________________________________________

WORM stands for Write Once Read Memory Wanted Once Read Memory Wanted Original Read Memory Write Original Read Memory       _____________________________________________________________________________________

The hardware in which data may be stored for a computer system is called Register Memory Chip Peripheral       _____________________________________________________________________________________

The Pentium processor was introduced 1991 1992 1993 1994       _____________________________________________________________________________________

The circumferences of the two concentric disks are divided into 100 sections each. For the outer disk, 100 of the sections are painted red and 100 of the sections are painted blue. For the inner disk, the sections are painted red and blue in an arbitrary manner. It is possible to align the two disks so that of the sections on the inner disks have their colours matched with the corresponding section on outer disk. 100 or more 125 or more 150 or more 175 or more       _____________________________________________________________________________________

Interrupts which are initiated by an I/O drive are  Internal External Software All of above       _____________________________________________________________________________________

Arithmetic shift left operation  Produces the same result as obtained with logical shift left operation Causes the sign bit to remain always unchanged Needs additional hardware to preserve the sign bit Is not applicable for signed 2s complement representation       _____________________________________________________________________________________

Fetch_And_Add(X,i) is an atomic Read-Modify-Write instruction that reads the value of memory location X, increments it by the value i, and returns the old value of X. It is used in the pseudocode shown below to implement a busy-wait lock. L is an unsigned integer shared variable initialized to 0. The value of 0 corresponds to lock being available, while any non-zero value corresponds to the lock being not available. AcquireLock(L){ while (Fetch_And_Add(L,1)) L = 1; } ReleaseLock(L){ L = 0; } This implementation fails as L can overflow fails as L can take on a non-zero value when the lock is actually available works correctly but may starve some processes works correctly without starvation       _____________________________________________________________________________________

A control character is sent at the beginning as well as at the end of each block in the synchronous-transmission in order to  Synchronize the clock of transmitter and receiver Supply information needed to separate the incoming bits into individual character Detect the error in transmission and received system. Both (A) and (C).       _____________________________________________________________________________________

The process of entering data into a storage location  Causes variation in its address number Adds to the contents of the location Is called a readout operation Is destructive of previous contents       _____________________________________________________________________________________

Of the following, which best characterizes computers that use memory-mapped I/O? The computer provides special instructions for manipulating I/O ports. I/O ports are placed at addresses on the bus and are accessed just like other memory locations. To perform an I/O operation, it is sufficient to place the data in an address register and call the channel to perform the operation. Ports are referenced only by memory-mapped instructions of the computer and are located at hardwired memory locations.       _____________________________________________________________________________________

The desirable characteristic of a memory system is  Speed and reliability Low power consumption Durability and compactness All of these       _____________________________________________________________________________________

In a k-way set associative cache, the cache is divided into v sets, each of which consists of k lines. The lines of a set are placed in sequence one after another. The lines in set s are sequenced before the lines in set (s+1). The main memory blocks are numbered 0 onwards. The main memory block numbered j must be mapped to any one of the cache lines from ( j mod v ) * k to ( j mod v ) * k + (k - 1) ( j mod v ) to ( j mod v ) + (k - 1) ( j mod k ) to ( j mod k ) + (v - 1) ( j mod k ) * v to ( j mod k ) * v + (v - 1)       _____________________________________________________________________________________

Intel 80486 was introduced in 1985 1986 1987 1989       _____________________________________________________________________________________

Which of the following are typical characteristics of a RISC machine? Highly pipielined Multiple register sets Both a and b None of these       _____________________________________________________________________________________

The amount of ROM needed to implement a 4 bit multiplier is 64 bits 128 bits 1 Kbits 2 Kbits       _____________________________________________________________________________________

On a non-pipelined sequential processor, a program segment, which is a part of the interrupt service routine, is given to transfer 500 bytes from an I/O device to memory. Initialize the address register Initialize the count to 500 LOOP: Load a byte from device Store in memory at address given by address register Increment the address register Decrement the count If count != 0 go to LOOP Assume that each statement in this program is equivalent to a machine instruction which takes one clock cycle to execute if it is a non-load/store instruction. The load-store instructions take two clock cycles to execute. The designer of the system also has an alternate approach of using the DMA controller to implement the same transfer. The DMA controller requires 20 clock cycles for initialization and other overheads. Each DMA transfer cycle takes two clock cycles to transfer one byte of data from the device to the memory. What is the approximate speedup when the DMA controller based design is used in place of the interrupt driven program based input-output? 3.4 4.3 5.1 6.3       _____________________________________________________________________________________

A charge coupled device has Low cost per bit High cost per bit Low density None of these       _____________________________________________________________________________________

WHAT IS A REGISTER? MEMORY ARRAY COUNTER NONE       _____________________________________________________________________________________

The bus which is used to transfer data from main memory to peripheral device is Data bus Input bus DMA bus Output bus