Verifone Interview


Here, we had three single man panels. They are seeing the subjects  taken and asking questions in that mainly. They didn t go deep into  any subject and they were just asking overview. When they catch any  new word they are asking about it.


These are some of the questions asked to us.(not to a single person.)


What is a finite Automata.

What is a turing machine.

How many processors are there in a pentium microprocessor. in Sparc.

Difference between risc and cisc.  is risc always fast.

What is a real time system.

Name some real time OS

What are the characteristics of Real time OS.

Is DOS a real time OS.

What is a kernel,shell.

What is binary search, traversal, hashing etc.

Given a scenario what is the suitable data structure.

Write a code to count the no. of 1 s in a binary rep. of a number.

Memory taken for char *, int * etc.

Char *cp; int *ip; cp++,ip++ - what is the result.

Compare the no. of bytes in unix and Dos for long char short int.

How to make programs portable on unix and Dos under such circumstances.

In c++, what is a constructor, destructor etc.

What is friend etc.

What is waterfall model, prototype model etc.

What is testing. what is unit testing, integration testing etc.

What is indexing in databases?

What is atomicity?

Can recursive pgms be written in C++, Write a recursive pgm to

Calculate factorial in c++.

What is best data structure to store the processes info in a real time

Operating system?


Verifone test Questions :

Some questions are:


1. A question (first one)on addition of fraction of inches

a. was the answer


2. There were 36 chairs. how many ways can they be placed such that all rows have equal no. of chairs and atleast three chairs are there in each row and there are atleast three rows.  5 ways.


3. There are 27 balls, of which 1 is heavier. given a balance how many times you need to weigh to find out the odd ball. 3 Weighs. 


4. Product of three consecutive nos. 210. What is the sum of two least numbers  11.


5. If the area of the sqaure is increased by 69 % how much the length of the side will increase?  30%


6. if the sum of five consecutive nos. 35? how many prime nos are there : 2 primes.


7. if the length of the rectangle is reduced by 20% and breath is increased by 20 % what is the net change ? 4 % decrease


8. A question on sets.

There are some 20 Basketball players & 30 Football players, and 25 cricket players. 1 of them plays all the three games. 8 of them plays atleast two games. They are 50 altogether. How many of them plays none of the games.


9. A question on directions. B is 20 miles east of A. D is 30 miles east of C. E is 10 miles north of D. C is 20 miles north of B. How far E is from A?  Some 3 questions on Reasoning like, 


10. If you say that giving stock options to employees increases the productivity of the company, which of the following sentences  support it.

A) Giving stock options increases the morale of the employees etc.,


11. Gamblers comes to the Amusement parks. There are some Amusement parks in each city. There are some gamblers in each city. So  what can you infer. 

A) Amusement park always have gamblers. etc.,


Technical Questions.


Electrical & Electronics : 15 Questions


1.A Circuit with nand gates.

(ans. may be XOR)


2.CMRR. relates to (options not in order)

voltage follower

non invering amplifier

inverting amplifier



3. Given a circuit , give the ouput.

(ans. may be triangular wave.)


4. o/p of an assembly code.

mulitply by 11.


5. how to handle asynchronous events.

a) polling

b) interrrupt



ii) Data Structures, Algo., & Complexity theory : 5 questions

iii) OS : 5 questions

iv) Networks and Hardware: 5 questions

v) Databases and Misc.: 5 questions

vi) C Pgm. : 5 questions


Some more 10 questions.


1. if W is a sequence of strings without a and W is its reversal then WaW is accepted by:


Context Free Grammars


2. Whether all recusive pgm can be writtten iteratively? yes.


3. What data structes you will use if you want to go to first record from  the last and vice versa?  doubly linked circular list


4. Given 10000 nos. and 48MB Memory. What is the complexity of the efficient sorting algo.? (the algo. is not mentioned) O(N)


5. Given a C code and ask what it does? code was something similar to Bubble sort and that particular code does the sorting in Desending order and the complexity is O(n^2)(which is the next question).


6. A code like this is given.

a. for(i=0;ib. for(i=num;i>0;i--)

Assuming no code optimization and assume that the microprocessor has flags etc. which one is correct.


b will execute faster.


7. If there are too many page faults what is the problem?


8. To ensure one pgm. doesnt corrupt other pgm. in a Multi-pgm enviornment what you should do?


9. Which one you will use to implement critical section? Binary Semaphore


10. Which one is not needed for Multi-processing. enviornment? options are: virtual memory,security,time sharing,none of the above.


11. Which one is not done by Data link layer ? bit stuffing, LRC,CRC,parity check


12. Which one is not related to Data link layer?


13. Which one is not suitable for client-server application? tcp/ip,message passing, rpc, none of the above.


14. What is SQL. Procedural Relational DB Query Language.


15. Indexing in databases give you options were like 1.efficient deleting and inserting 2.efficient deleting. etc.


16. int a=1,b=2,c=3;



What is the output?


17. Scope of Static Variable ............ in a file.


18. for(i=0; i<=10;i++,printf("%d",i)); +- (+- is there in the questions)


20. Real Time Os should have

a) fast context switch

b) Virtual memory etc.


21. Messages are transferred in some E71 code, where after 7 bits of data, 1 bit of stopping data is to be transferred. what should be done. options were like 

a) send directly

b) send after encoding etc.


22. There are three processes A, B, C. A sends data to B. B removes the header stores it and sends the data to C. C returns it to B. B receives the message, identifies the message and adds the header that was stored and sends to A.B receives the messages from C such that atmost m messages B are pending.  Identify the best Data Structure.


23. A question in compiler about the heap and stack allocation of memory.


24. struct


char a[3];

int b;


char *cp;

a) size of x is 7.




d) cp takes the size of a pointer.

d ) is the ans.

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