ISRO CS 2020

Question 1

Regression testing is primarily related to

• Functional testing
• Development testing
• Data flow testing
• Maintenance testing

Question 2

Of the following sort algorithms, which has execution time that is least dependent on initial ordering of the input ?

• Insertion sort
• Quick sort
• Merge sort
• Selection sort

Question 3

The following circuit compares two 2-bit binary numbers, X and Y represented by X1X0 and Y1Y0 respectively. (X0 and Y0 represent Least Significant Bits) Under what condition Z will be 1 ?

• X > Y
• X < Y
  
• X = Y
• X! = Y

Question 4

What is the availability of the software with following reliability figures.

Mean Time Between Failures (MTBF) is 20 days
Mean Time To Repair (MTTR) is 20 hours 

• 90%
• 96%
• 24%
• 50%

Question 5

What is the defect rate for Six sigma ?

• 1.0 defect per million lines of code
• 1.4 defects per million lines of code
• 3.0 defects per million lines of code
• 3.4 defects per million lines of code

Question 6

Consider a 5-segment pipeline with a clock cycle time 20 ns in each sub operation. Find out the approximate speed-up ratio between pipelined and non-pipelined system to execute 100 instructions. (If an average, every five cycles, a bubble due to data hazard has to be introduced in the pipeline.).

• 5
• 4.03
• 4.81
• 4.17

Question 7

Consider a 32-bit processor which supports 70 instructions. Each instruction is 32 bit long and has 4 fields namely opcode, two register identifiers and an immediate operand of unsigned integer type. Maximum value of the immediate operand that can be supported by the processor is 8191. How many registers the processor has ?

• 32
• 64
• 128
• 16

Question 8

In a 8-bit ripple carry adder using identical full adders, each full adder takes 34 ns for computing sum. If the time taken for 8-bit addition is 90 ns, find time taken by each full adder to find carry.

• 6 ns
• 7 ns
• 10 ns
• 8 ns

Question 9

Following Multiplexer circuit is equivalent to

• Sum equation of full adder
• Carry equation of full adder
• Borrow equation for full subtractor
• Difference equation of a full subtractor

Question 10

A stack is implemented with an array of ‘A[0...N – 1]’ and a variable ‘pos’. The push and pop operations are defined by the following code.

push (x)
  A[pos] ← x
  pos ← pos – 1
end push

pop ( )
  pos ← pos + 1
  return A[pos]
end pop 

Which of the following will initialize an empty stack with capacity N for the above implementation ?

• pos ← –1
• pos ← 0
• pos ← 1
• pos ← N – 1