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ANALOG ELECTRONICS INTERVIEW QUESTIONS-PART II
=======================================================

1) what are the different modes of operation of mosfet and BJT ( Linear & Switching and Cut off)
2) how do you implement a current source using BJT or MOSFET.
3) what is hysteresis. and what are the advantages and disadvantages of it.
4) what are the effects of vias on PCB.
5) how do you design a voltage to frequency converter.
6) 8051 architecture.
7) Ethernet communication
8) Different types of serial communications ex. I2C
9) Different types of memory devices ( ROM, RAM,SRAM and EEPROM etc)
10) How to select an Opto coupler.
11) what is the main advantage of using a bridge rectifier rather than using a full wave rectifier.
12) what are the applications of zener diode.
13) what are the applications of schottky diode.
14) why do we need a Gate Driver for Mosfet in Switching operations.
15) what is pulse width modulation. give any examples.
16) how does SMPS ( Switch mode power supply works)
17) what does it mean by PID control.
18) what are different types of Flip flops.
19) what is meant by quiescent current and what is the significance of it.
20) How does an instrumentation amplifier differs from normal operational amplifier
21) What are snubbers and how does they protect switching circuits.
22) What is sampling time and how to fix it.
23) What is Rogowski coil and what are its advantages over normal current transformer.
24) What is Ringing, Overshoot and Undershoot how to reduce them.
25) what is a relaxation oscillator.
26) what is hysteresis.
27) what are the different applications of comparators.
28) how does a Unijunction Transistor works.
29) how does programable unijunction transistor works.
30) what are the differences between ASIC, FPGA and CPLD.
31) how to select a network processor.
32) what is the difference between radiated emissions and conducted emissions how to detect and reduce them.
33) what are the different types of negative resistance devices and what are their applications.
34) What is the major application of Zener Diode.
35) When do we use Schottky diode.
36) What is the difference between RISC and CISC processors.
37) What is tri-state logic.
38) What is the difference between Hardware reset and Software reset.
39) How do you determine the response time of any circuit.[loop response]
40) What is an integrator how do design it.
41) What factors will impact the characteristic impedance of the PCB (Dielectric property of insulating material, Seperation between the planes, thickness of the trace.)
42) What are the advantages of using differential signal routing in PCB.
43) How do we make sure that the impedance matching between driver and reciever are maintained?

ANALOG ELECTRONICS INTERVIEW QUESTIONS & TUTORIALS
==================================================

                     Its said that Analog Electronics is the most difficult area in elctronics engineering stream and analog electronics engineers and circuit designers are the most intelligent among the
elctronics engineers.Hence analog electronics questions are asked in most Electronics Interviews
for testing the indepth knowledge of the candidate.Here is a question bank for Analog Electronics containing important interview questions asked in major technical interviews  a from this topic.

ANALOG ELECTRONICS --PART I
===========================
1) How does a MosFet works.
2) What are different types of BJT configurations and when do we use them.
3) What is the difference between TTL and CMOS ?
4) What is noise margin?
5) Which is the most important pin the micro-controller?
6) Explain about Ground Bounce and Vcc Sag.
7) What is EMI and what are different types of it.
8) One question on any kind of sensors you are aware of Ex: hall sensor etc.
9) What is LVDT.
10) How do we select the correct value of decoupling capacitor (or) what is the purpose of using a decoupling capacitor.
11) What is parasitic capacitance & what are the effects of it.
12) What is the difference between microprocessor and micro controller.
13) What are different types of micro processor architectures
14) What is the difference between by pass capacitor and decoupling capacitor
15) How do you select an op amp ( this can apply to other components also)
16) Single ended and Differential signals.
17) How do you decide the layer stack up on PCB.
18) Questions fromFilter Design: Analog and Digital Filters, different types of filters.
19) What is signal integrity?
20) What is meta stability?
21) Difference between CPLD and FPGA
22) Difference between DDR and DDR2 RAM.
23) What is termination? What are the different types of terminations?
24) When do you need to use an heat sink and how do you decide on that?
25) What is the difference between clock buffer and clock driver?
26) What is Jitter?
27) What is gain bandwidth product?
28) Define settling time of op amp?
29) What is slew rate of op amp, define common mode rejection ratio and input offset voltage?
30) What is the difference between static response and dynamic response?
31) What is an integrator and differentiator?
32) Define the parameters of an ADC or types of ADC etc?
33) What is sample and hold circuit?
34) What is a comparator?( some questions related to schmitt trigger or positive feed back of op amp)
35) What is Fan Out?
36) Different types of Voltage regulators. ( Linear, Switching etc..)
37) How do you create a basic delay circuit?
38) What is characteristic impedance?
39) What is ringing, undershoot and overshoot of a signal why do they occur and how to reduce them?
40)What are the parameters to be taken into consideration while selecting a mosfet?

SQL QUESTIONS & ANSWERS

1. Which is the subset of SQL commands used to manipulate Oracle Database structures, including tables?
Data Definition Language (DDL)

2. What operator performs pattern matching?
LIKE operator

3. What operator tests column for the absence of data?
IS NULL operator

4. Which command executes the contents of a specified file?
START or @

5. What is the parameter substitution symbol used with INSERT INTO command?
&

6. Which command displays the SQL command in the SQL buffer, and then executes it?
RUN

7. What are the wildcards used for pattern matching?
_ for single character substitution and % for multi-character substitution

8. State true or false. EXISTS, SOME, ANY are operators in SQL.
True

9. State true or false. !=, <>, ^= all denote the same operation.
True

10. What are the privileges that can be granted on a table by a user to others?
Insert, update, delete, select, references, index, execute, alter, all

11. What command is used to get back the privileges offered by the GRANT command?
REVOKE

12. Which system tables contain information on privileges granted and privileges obtained?
USER_TAB_PRIVS_MADE, USER_TAB_PRIVS_RECD

13. Which system table contains information on constraints on all the tables created?
USER_CONSTRAINTS

14. TRUNCATE TABLE EMP;
DELETE FROM EMP;
Will the outputs of the above two commands differ?
Both will result in deleting all the rows in the table EMP.

15. What is the difference between TRUNCATE and DELETE commands?
TRUNCATE is a DDL command whereas DELETE is a DML command. Hence DELETE operation can be rolled back, but TRUNCATE operation cannot be rolled back. WHERE clause can be used with DELETE and not with TRUNCATE.

16. What command is used to create a table by copying the structure of another table?
Answer :
CREATE TABLE .. AS SELECT command
Explanation :
To copy only the structure, the WHERE clause of the SELECT command should contain a FALSE statement as in the following.
CREATE TABLE NEWTABLE AS SELECT * FROM EXISTINGTABLE WHERE 1=2;
If the WHERE condition is true, then all the rows or rows satisfying the condition will be copied to the new table.

17. What will be the output of the following query?
SELECT REPLACE(TRANSLATE(LTRIM(RTRIM('!! ATHEN !!','!'), '!'), 'AN', '**'),'*','TROUBLE') FROM DUAL;
TROUBLETHETROUBLE

18. What will be the output of the following query?
SELECT DECODE(TRANSLATE('A','1234567890','1111111111'), '1','YES', 'NO' );
Answer :
NO
Explanation :
The query checks whether a given string is a numerical digit.

19. What does the following query do?
SELECT SAL + NVL(COMM,0) FROM EMP;
This displays the total salary of all employees. The null values in the commission column will be replaced by 0 and added to salary.


20. Which date function is used to find the difference between two dates?
MONTHS_BETWEEN

21. Why does the following command give a compilation error?
DROP TABLE &TABLE_NAME;
Variable names should start with an alphabet. Here the table name starts with an '&' symbol.

22. What is the advantage of specifying WITH GRANT OPTION in the GRANT command?
The privilege receiver can further grant the privileges he/she has obtained from the owner to any other user.

23. What is the use of the DROP option in the ALTER TABLE command?
It is used to drop constraints specified on the table.

24. What is the value of ‘comm’ and ‘sal’ after executing the following query if the initial value of ‘sal’ is 10000?
UPDATE EMP SET SAL = SAL + 1000, COMM = SAL*0.1;
sal = 11000, comm = 1000

25. What is the use of DESC in SQL?
Answer :
DESC has two purposes. It is used to describe a schema as well as to retrieve rows from table in descending order.
Explanation :
The query SELECT * FROM EMP ORDER BY ENAME DESC will display the output sorted on ENAME in descending order.

26. What is the use of CASCADE CONSTRAINTS?
When this clause is used with the DROP command, a parent table can be dropped even when a child table exists.

27. Which function is used to find the largest integer less than or equal to a specific value?
FLOOR

28. What is the output of the following query?
SELECT TRUNC(1234.5678,-2) FROM DUAL;
1200

FREQUENTLY ASKED JAVA QUESTIONS WITH ANSWERS

1.what is a transient variable?
A transient variable is a variable that may not be serialized.

2.which containers use a border Layout as their default layout?
The window, Frame and Dialog classes use a border layout as their default layout.

3.Why do threads block on I/O?
Threads block on i/o (that is enters the waiting state) so that other threads may execute while the i/o Operation is performed.

4. How are Observer and Observable used?
Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects.

5. What is synchronization and why is it important?
With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object's value. This often leads to significant errors.

6. Can a lock be acquired on a class?
Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object..

7. What's new with the stop(), suspend() and resume() methods in JDK 1.2?
The stop(), suspend() and resume() methods have been deprecated in JDK 1.2.

8. Is null a keyword?
The null value is not a keyword.

9. What is the preferred size of a component?
The preferred size of a component is the minimum component size that will allow the component to display normally.

10. What method is used to specify a container's layout?
The setLayout() method is used to specify a container's layout.

11. Which containers use a FlowLayout as their default layout?
The Panel and Applet classes use the FlowLayout as their default layout.

12. What state does a thread enter when it terminates its processing?
When a thread terminates its processing, it enters the dead state.

13. What is the Collections API?
The Collections API is a set of classes and interfaces that support operations on collections of objects.

14. Which characters may be used as the second character of an identifier,
but not as the first character of an identifier?
The digits 0 through 9 may not be used as the first character of an identifier but they may be used after the first character of an identifier.

15. What is the List interface?
The List interface provides support for ordered collections of objects.

16. How does Java handle integer overflows and underflows?
It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.

17. What is the Vector class?
The Vector class provides the capability to implement a growable array of objects

18. What modifiers may be used with an inner class that is a member of an outer class?
A (non-local) inner class may be declared as public, protected, private, static, final, or abstract.

19. What is an Iterator interface?
The Iterator interface is used to step through the elements of a Collection.

20. What is the difference between the >> and >>> operators?
The >> operator carries the sign bit when shifting right. The >>> zero-fills bits that have been shifted out.

21. Which method of the Component class is used to set the position and
size of a component?
setBounds()

22. How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?
Unicode requires 16 bits and ASCII require 7 bits. Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

23What is the difference between yielding and sleeping?
When a task invokes its yield() method, it returns to the ready state. When a task invokes its sleep() method, it returns to the waiting state.

24. Which java.util classes and interfaces support event handling?
The EventObject class and the EventListener interface support event processing.

25. Is sizeof a keyword?
The sizeof operator is not a keyword.

26. What are wrapped classes?
Wrapped classes are classes that allow primitive types to be accessed as objects.

27. Does garbage collection guarantee that a program will not run out of memory?
Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection

28. What restrictions are placed on the location of a package statement
within a source code file?
A package statement must appear as the first line in a source code file (excluding blank lines and comments).

29. Can an object's finalize() method be invoked while it is reachable?
An object's finalize() method cannot be invoked by the garbage collector while the object is still reachable. However, an object's finalize() method may be invoked by other objects.

30. What is the immediate superclass of the Applet class?
Panel

31. What is the difference between preemptive scheduling and time slicing?
Under preemptive scheduling, the highest priority task executes until it enters the waiting or dead states or a higher priority task comes into existence. Under time slicing, a task executes for a predefined slice of time and then reenters the pool of ready tasks. The scheduler then determines which task should execute next, based on priority and
other factors.

32. Name three Component subclasses that support painting.
The Canvas, Frame, Panel, and Applet classes support painting.

33. What value does readLine() return when it has reached the end of a file?
The readLine() method returns null when it has reached the end of a file.

34. What is the immediate superclass of the Dialog class?
Window

35. What is clipping?
Clipping is the process of confining paint operations to a limited area or shape.

36. What is a native method?
A native method is a method that is implemented in a language other than Java.

37. Can a for statement loop indefinitely?
Yes, a for statement can loop indefinitely. For example, consider the following:
for(;;) ;

38. What are order of precedence and associativity, and how are they used?
Order of precedence determines the order in which operators are evaluated in expressions. Associatity determines whether an expression is evaluated left-to-right or right-to-left

39. When a thread blocks on I/O, what state does it enter?
A thread enters the waiting state when it blocks on I/O.

40. To what value is a variable of the String type automatically initialized?
The default value of an String type is null.

41. What is the catch or declare rule for method declarations?
If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.

42. What is the difference between a MenuItem and a CheckboxMenuItem?
The CheckboxMenuItem class extends the MenuItem class to support a menu item that may be checked or unchecked.

43. What is a task's priority and how is it used in scheduling?
A task's priority is an integer value that identifies the relative order in which it should be executed with respect to other tasks. The scheduler attempts to schedule higher priority tasks before lower priority tasks.

44. What class is the top of the AWT event hierarchy?
The java.awt.AWTEvent class is the highest-level class in the AWT event-class hierarchy.

45. When a thread is created and started, what is its initial state?
A thread is in the ready state after it has been created and started.

46. Can an anonymous class be declared as implementing an interface and extending a class?
An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.

47. What is the range of the short type?
The range of the short type is -(2^15) to 2^15 - 1.

48. What is the range of the char type?
The range of the char type is 0 to 2^16 - 1.

49. In which package are most of the AWT events that support the event-delegation
model defined?
Most of the AWT-related events of the event-delegation model are defined in the java.awt.event package. The AWTEvent class is defined in the java.awt package.

50. What is the immediate superclass of Menu?
MenuItem

RDBMS
==============

1) When a single entity is related to itself then the relationship is
termed as
A) ONE -TO-ONE
B) ONE-TO-MANY
C) RECURSIVE
D) MANY-TO-MANY

2)_____ means allowing objects of different types to be
considered as examples of higher level set
A) AGGREGATION
B) SPECIALIZATION
C) GENERALIZATION
D) DECOMPOSITION

3) The primary characteristic of a key field as that it must be
A) A NAME
B) TEXT
C) UNIQUE
D) ALL OF THE OTHER OPTION LISTED FOR THIS QUESTION

4) What kind of relationship exist between customers and salespersons if
each customer may have one or more salespersons, and each salesperson
may have one or more customers?
A) one-to-one
B) one to many
C) many to many
D) many to one

5) The following is a valid SET operation.
A) Join
B) Insert
C) Select
D) Difference

6) In an employ table, the field which can be taken as a Primary key
A) name
B) employ_id
C) age


7) A relation R is said to be in the , if it is in BCNF and
there are non-trivial multi valued dependencies.
A) 1st NF
B) 2nd NF
C) 3rd NF
D) 4th NF

8) A occurs when a weak entity does not have a
candidate key and its instances are indistinguishable without a
relationship with another entity.
A) Existence dependency
B) Identifier dependency
C) Referential dependency
D) None of the other option listed for this question

9) ____ is /are sample(s) of data model.
A) Relational
B) Rational
C) Entity- relationship
D) None of the other option listed for this question

10) In hierarchical database,
A) There is one to many relationship
B) A child may have more than one parent
C) A parent may have more than one child
D) There is no restriction on the number of parents a child may have or
the number of children a parent may have

11) The term "inner join" refers to:
A) Joins between two tables in the same schema.
B) An equality join based on one column from each table.
C) A table joined with itself.
D) A Cartesian product join.

12) Which type of join is used in this query?

SELECT last_name "Name", hire_date "Hire Date", loc "Location"
FROM employee, department
WHERE employee.deptno = department.deptno.
A) Outer join
B) Self join
C) Equijoin
D) Non-equijoin

13) A sales database has two table - SALESPERSON and CUSTOMERS as below:

SALESPEOPLE
------------------------------------------------------
snum NUMBER
sname VARCHAR2(10)

CUSTOMER
------------------------------------------------------
snum NUMBER
cname VARCHAR2(10)

The management wants to know the mapping of salespersons to their
Customers without excluding those salespersons that are not currently assigned.
What would be the most appropriate condition, which can be applied on the
Query to accomplish the above task?

A) salespeople.snum(+) = customers.snum
B) salespeople.snum = customers.snum(+)
C) salespeople.snum = customers.snum
D) salespeople.snum(+) = customers.snum(+)

14) join returns those rows from a table which have
no direct match in the other table.

A) Outer join
B) Inner join
C) Equi join
D) Self join

15) To produce a meaningful result set without any Cartesian products,
What is the minimum number of conditions that should appear in the WHERE
clause of a four table join?

A) 1
B) 4
C) 2
D) 8

UNIX Questions
================================

1) Which one works as a command interpretor
A) Hardware B) Kernal C) Shell D) CPU

2) The major no for a floppy disk device is
A) 1 B) 3 C) 2 D) 4

3) chown
A) Changes the mode of operation to kernel mode
B) Creates a thread
C) Changes the users and/or group ownership of each given file
D) Creates a child process

4) lilo
A) Uninstalls the boot loader
B) Installs the boot loader
C) Is a login utility
D) Invokes a daemon to logoff

5) netdevice
A) Provides low level access to Linux network devices
B) Provides low level access to Linux storage devices
C) Provides an interface to communicate with graphic devices
D) None of the other option listed for this question

6) The process which terminates before the parent process exits, is
called
as
A) Zombie
B) Orphan
C) Child
D) None of the other option listed for this question

7) Context switch means
A) Kernel switches from executing one process to another.
B) Process switches from kernel mode to user mode.
C) Process switches from user mode to kernel mode.
D) None of the other option listed for this question

8) The following socket provides two way, sequenced, reliable and
unduplicated flow of data with no record boundaries.
A) Sequential packet socket
B) Datagram socket
C) Stream socket
D) Raw socket

9) Identify the point(s) that is not true w.r.t. signals

A) Signals are software generated interrupts that are sent to a process
when an event happens
B) Signal delivery is analogous to hardware interrupts in that a signal
can be blocked from being delivered in the future.
C) Most signals are synchronous by nature.
D) Most signal cause termination of the receiving process if no action
is taken by the process in response to the signal.

10) Identify the point(s) that is true with respect to Semaphore

A) Only one process at a time can update a semaphore.
B) All the other options listed for this question
C) They are often used to monitor and control the availability of system
resources such as shared memory segments.
D) Is a process with exclusive use of a semaphore terminates abnormally
and fails to undo the operation or free the semaphore, the semaphore stays
locked in the state the process left it.

Questions related to shell scripting...
11)What is the use of script function?

12)Difference of uses of 'mv' function and 'rm' function

13)'chmod' function

14)'head' and 'tail' function

15)'grep' function

FREQUENTLY ASKED C PROGRAMMING QUESTIONS...
--------------------------------------------------------------
How to add 2 numbers without + sign?

Suggest one method which is equivalent to dividing a number by 2?

Write a program to reverse a given number using recursion?

What is the output of printf("%d")?

What is the difference between "printf(...)" and "sprintf(...)"?

Write a program to find the factorial of given number using recursion?

What does static variable mean?

What is a structure?

What are the differences between structures and arrays?

In header files whether functions are declared or defined?

What are the differences between malloc() and calloc()?

What are macros? What are the advantages and disadvantages?

Difference between pass by reference and pass by value?

What is static identifier?

Where are the auto variables stored?

Where does global, static, local, register variables, free memory and C Program instructions get stored?

What is a pointer?

Difference between const char* p and char const* p

Difference between arrays and linked list?

What is the similarity between a Structure, Union and enumeration?

What are enumerations?

Describe about storage allocation and scope of global, extern, static, local and register variables?

What are register variables? What are the advantage of using register variables?

What is the use of typedef?

Can we specify variable field width in a scanf() format string? If possible how?

Out of fgets() and gets() which function is safe to use and why?

Difference between strdup and strcpy?

What is recursion?

Differentiate between a for loop and a while loop? What are it uses?

What are the different storage classes in C?

Write down the equivalent pointer expression for referring the same element a[i][j][k][l]?

What is difference between Structure and Unions?

What the advantages of using Unions?

What are the advantages of using pointers in a program?

What is the difference between Strings and Arrays?

In a header file whether functions are declared or defined?

What is a far pointer? where we use it?

How will you declare an array of three function pointers where each function receives two ints and returns a float?

What is a NULL Pointer? Whether it is same as an uninitialized pointer?

What is a NULL Macro? What is the difference between a NULL Pointer and a NULL Macro?

What does the error ‘Null Pointer Assignment’ mean and what causes this error?

What is near, far and huge pointers? How many bytes are occupied by them?

How would you obtain segment and offset addresses from a far address of a memory location?

Are the expressions arr and *arr same for an array of integers?

Does mentioning the array name gives the base address in all the contexts?

Explain one method to process an entire string as one unit?

Can a Structure contain a Pointer to itself?

How can we check whether the contents of two structure variables are same or not?

How are Structure passing and returning implemented by the complier?

How can we read/write Structures from/to data files?

What is the difference between an enumeration and a set of pre-processor # defines?

What do the ‘c’ and ‘v’ in argc and argv stand for?

Are the variables argc and argv are local to main?

What is the maximum combined length of command line arguments including the space between adjacent arguments?

If we want that any wildcard characters in the command line arguments should be appropriately expanded, are we required to make any special provision? If yes, which?

Does there exist any way to make the command line arguments available to other functions without passing them as arguments to the function?

What are bit fields? What is the use of bit fields in a Structure declaration?

To which numbering system can the binary number 1101100100111100 be easily converted to?

Which bit wise operator is suitable for checking whether a particular bit is on or off?

Which bit wise operator is suitable for turning off a particular bit in a number?

Which bit wise operator is suitable for putting on a particular bit in a number?

Which bit wise operator is suitable for checking whether a particular bit is on or off?

Which one is equivalent to multiplying by 2?

Left shifting a number by 1 or
Left shifting an unsigned int or char by 1?

Write a program to compare two strings without using the strcmp() function.

Write a program to concatenate two strings.

What will be the output of the code below:
main()
{
int x=10,y=25;
x=y++ + x++;
y= ++y + ++x;
printf(“%d%d\n”,x,y)
;
}

What will be the output of the code below:
main()
{
int x=4;
printf(“%d,%d,%d\n”,x,x<<2,>>2)
;
}

What will be the output of the code below:
main()
{
int x=15, y=20;
x = x++;
y = ++y;
printf(“%d %d\n”,x,y);

}

What are the advantages of a macro over a function?

What is binary sort?Explain with an example code?

C++ FREQUENTLY ASKED QUESTIONS
------------------------------------------------

What do you mean by Object Oriented Programming technique?

What are the properties of OOP technique?

What do you mean by inheritance? Explain using an example?

What is multiple inheritance (virtual inheritance)? What are its advantages and disadvantages?

What is polymorphism?

What is inline function?

How do you allocate dynamic memory in C++?

What is the difference between C and C++?

What is a void return type?

How is it possible for two String objects with identical values not to be equal under the == operator?

What is the difference between a while statement and a do statement?

Write a program to print all the prime numbers below a given number.

Write a program for reversing a given number without using string function.

Can a for statement loop indefinitely?

How do you link a C++ program to C functions?

What is the basic difference between a class and a structure?

How can you tell what shell you are running on UNIX system?

How do you find out if a linked-list has an end? (i.e. the list is not a cycle)

How do you write a function that can reverse a linked-list?

Can a copy constructor accept an object of the same class as parameter, instead of reference of the object?

What is a local class?

What is a nested class?

What are the access privileges in C++? What is the default access level?

How do you access the static member of a class?

What does extern int func(int *, Foo) accomplish?

When the processor wakes up after power on, it goes to a particular memory location. What is that memory location called?

What is the difference between Mutex and Binary semaphore?

Write a program to set 2nd bit in a 32 bit register with memory location 0×2000?

COMMUNICATION INTERVIEW QUESTIONS
----------------------------------------------------
Important Topics
---------------------------------

Analog Modulation

Amplitude Modulation

Frequency Modulation

Modulation Index,Bandwidth....

Nyquist Criteria for communication

Channel Capacity Theorem

Pulse Code Modulation

Adaptive Pulse Code Modulation

Differential Pulse Code Modulation

Radar Types

Primary and Secondary Radars

MDI

Frequency ranges- HF,VHF,UHF,Microwave….

Digital Modulation Techniques

FSK, PSK, QPSK, MSK, Gaussian MSK


Sample Questions

1. A 2MB PCM (pulse code modulation) has…

a) 32 channels
b) 30 voice channels & 1 signaling channel.
c) 31 voice channels & 1 signaling channel.
d) 32 channels out of which 30 voice channels, 1 signaling channel, & 1 synchronization channel.

Ans: (c)

2. Time taken for 1 satellite hop in voice communication is…

a) 1/2 second
b) 1 seconds
c) 4 seconds
d) 2 seconds

Ans: (a)

3. Max number of satellite hops allowed in voice communication is:

a) only one
b) more han one
c) two hops
d) four hops

Ans: (c)

4. What is the maximal decimal number that can be accommodated in a byte?

a) 128
b) 256
c) 255
d) 512

Ans: (c)

5. Conditional results after execution of an instruction in a micro processor is stored in…

a) register
b) accumulator
c) flag register
d) flag register part of PSW(Program Status Word)

Ans: (d)

6. Frequency at which VOICE is sampled is…

a) 4 KHz
b) 8 KHz
c) 16 KHz
d) 64 KHz

Ans: (a)

7. Line of sight is…

a) Straight Line
b) Parabolic
c) Tx & Rx should be visible to each other
d) none of the above

Ans: (c)

8. Purpose of PC(Program Counter) in a MicroProcessor is…

a) To store address of TOS(Top Of Stack)
b) To store address of next instruction to be executed.
c) count the number of instructions.
d) to store base address of the stack.

Ans: (b)

9. What action is taken when the processor under execution is interrupted by a non-maskable interrupt?

a) Processor serves the interrupt request after completing the execution of the current instruction.
b) Processor serves the interrupt request after completing the current task.
c) Processor serves the interrupt request immediately.
d) Processor serving the interrupt request depends upon the priority of the current task under execution.

Ans: (a)

10. The status of the Kernel is…

a) task
b) process
c) not defined.
d) none of the above.

Ans: (b)

11. What is the nominal voltage required in subscriber loop connected to local exchange?

a) +48 volts
b) -48 volts
c) 230 volts
d) 110 volts

12. To send a data packet using datagram , connection will be established…

a) before data transmission.
b) connection is not established before data transmission.
c) no connection is required.
d) none of the above.

Ans: (c)

13. Word alignment is…

a) aligning the address to the next word boundary of the machine.
b) aligning to an even boundary.
c) aligning to a word boundary.
d) none of the above.

Ans: (a)

14. When a C function call is made, the order in which parameters passed to the function are pushed into the stack is…

a) left to right
b) right to left
c) bigger variables are moved first than the smaller variales.
d) smaller variables are moved first than the bigger ones.
e) none of the above.

Ans: (b)

15. What is the type of signaling used between two exchanges?

a) inband
b) common channel signaling
c) any of the above
d) none of the above.

Ans: (a)

16. Buffering is…

a) the process of temporarily storing the data to allow for small variation in device speeds
b) a method to reduce cross talks
c) storage of data within transmitting medium until the receiver is ready to receive.
d) a method to reduce routing overhead.

Ans: (a)

17. Memory allocation of variables declared in a program is…

a) allocated in RAM.
b) allocated in ROM.
c) allocated on stack.
d) assigned to registers.

Ans: (c)

18. A software that allows a personal computer to pretend as a computer terminal is …

a) terminal adapter
b) bulletin board
c) modem
d) terminal emulation

Ans: (d)

OPERATING SYESTEMS- INTERVIEW QUESTIONS
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What is an OPERATING SYSTEM?
An Operating System is a software program that enables the computer hardware to communicate and operate with the computer software.

What are the basic functions of an OPERATING SYSTEM?

What are the different types of OPERATING SYSTEM?
Graphical User Interface OS
Multi-user OS
Multiprocessing OS
Multitasking OS
Multithreading OS

What is Graphical User Interface OS?
Short for Graphical User Interface, a GUI Operating System contains graphics and icons and is commonly navigated by using a computer mouse. See our GUI dictionary definition for a complete definition. Below are some examples of GUI Operating Systems.
System 7.x
Windows 98
Windows CE

What is Multi-user OS?
Multi-user Operating System allows for multiple users to use the same computer at the same time and/or different times. See our multi-user dictionary definition for a complete definition for a complete definition. Below are some examples of multi-user Operating Systems.
Linux
Unix
Windows 2000
Windows XP
Mac OS X

What is Multiprocessing OS?
An Operating System capable of supporting and utilizing more than one computer processor. Below are some examples of multiprocessing Operating Systems.
Linux
Unix
Windows 2000
Windows XP
Mac OS X

What is Multitasking OS?
An Operating system that is capable of allowing multiple software processes to run at the same time. Below are some examples of multitasking Operating Systems.
Unix
Windows 2000
Windows XP
Mac OS X

Why paging is used?

What is virtual memory?
Virtual memory is hardware technique where the system appears to have more memory that it actually does. This is done by time-sharing, the physical memory and storage parts of the memory one disk when they are not actively being used.

What is Throughput, Turnaround time, waiting time and Response time?
Throughput – number of processes that complete their execution per time unit. Turnaround time – amount of time to execute a particular process.
Waiting time – amount of time a process has been waiting in the ready queue. Response time – amount of time it takes from when a request was submitted until the first response is produced, not output (for time-sharing environment).

What is a Real-Time Operating System (RTOS)?

8086 MICROPROCESSOR INTERVIEW QUESTIONS&ANSWERS
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What is a Microprocessor?
Microprocessor is a program-controlled device, which fetches the instructions from memory, decodes and executes the instructions. Most Micro Processor are single- chip devices.

What is the difference between microprocessor and microcontroller?
The major difference is microprocessor doesn’t have inbuilt memory but micro-controller has inbuilt memory .In Microprocessor more op-codes, few bit handling instructions. But in Microcontroller: fewer op-codes, more bit handling Instructions. Micro-controller can be defined as a device that includes micro processor, memory, & input / output signal lines on a single chip.

Give examples for 8 / 16 / 32 bit Microprocessor?
8-bit Processor - 8085 / Z80 / 6800;
16-bit Processor - 8086 / 68000 / Z8000;
32-bit Processor - 80386 / 80486.

Why 8085 processor is called an 8 bit processor?
Because 8085 processor has 8 bit ALU (Arithmetic Logic Review).

Expand HCMOS?
High-density n- type Complimentary Metal Oxide Silicon field effect transistor.

What does microprocessor speed depend on?
The processing speed depends on DATA BUS WIDTH.

What is the Maximum clock frequency in 8086?
5 Mhz is the Maximum clock frequency in 8086

Is the address bus unidirectional? Is the data bus is Bi-directional?
The address bus is unidirectional because the address information is always given by the Micro Processor to address a memory location of an input / output devices.
The data bus is Bi-directional because the same bus is used for transfer of data between Micro Processor and memory or input / output devices in both the direction.

What is the disadvantage of microprocessor?
It has limitations on the size of data. Most Microprocessor does not support floating-point operations.

What is the difference between primary & secondary storage device?
In primary storage device the storage capacity is limited. It has a volatile memory. In secondary storage device the storage capacity is larger. It is a nonvolatile memory. Primary devices are: RAM / ROM.
Secondary devices are: Floppy disc / Hard disk.

Difference between SRAM and DRAM?
Static RAM: No refreshing, 6 to 8 MOS transistors are required to form one memory cell, Information stored as voltage level in a flip flop.
Dynamic RAM: Refreshed periodically, 3 to 4 transistors are required to form one memory cell, Information is stored as a charge in the gate to substrate capacitance.

What is an interrupt?
Interrupt is a signal send by external device to the processor so as to request the processor to perform a particular work.

What are the different types of interrupts?
Maskable and Non-maskable interrupts.

What is cache memory?
Cache memory is a small high-speed memory. It is used for temporary storage of data & information between the main memory and the CPU (center processing unit). The cache memory is only in RAM.

Expand DMA?
Direct Memory Access

Differentiate between RAM and ROM?
RAM: Random Access Memory. Read / Write memory, High Speed, Volatile Memory. ROM: Read only memory, Low Speed, Non Volatile Memory

What is NV-RAM?
Nonvolatile Read Access Memory, also called Flash memory.

What is a flag?
Flag is a flip-flop used to store the information about the status of a processor and the status of the instruction executed most recently

What are the flags in 8086?
In 8086 Carry flag, Parity flag, Auxiliary carry flag, Zero flag, Overflow flag, Trace flag, Interrupt flag, Direction flag, and Sign flag.

What is meant by Maskable interrupt?
An interrupt that can be turned off by the programmer is known as Maskable interrupt.

What is Non-Maskable interrupt?
An interrupt which can be never be turned off (ie.disabled) is known as Non-Maskable interrupt.

Which interrupts are generally used for critical events?
Non-Maskable interrupts are used in critical events. Such as Power failure, Emergency, Shut off etc.

Give examples for Maskable interrupts?
RST 7.5, RST6.5, RST5.5 are Maskable interrupts

Give example for Non-Maskable interrupts?
Trap is known as Non-Maskable interrupts, which is used in emergency condition.

What are the various segment registers in 8086?
Code, Data, Stack, Extra Segment registers in 8086.

Which Stack is used in 8086?
FIFO (First In First Out) stack is used in 8086.In this type of Stack the first stored information is retrieved first.

What is SIM and RIM instructions?
SIM is Set Interrupt Mask. Used to mask the hardware interrupts.
RIM is Read Interrupt Mask. Used to check whether the interrupt is Masked or not.

What is Tri-state logic?
Three Logic Levels are used and they are High, Low, High impedance state. The high and low are normal logic levels & high impedance state is electrical open circuit conditions. Tri-state logic has a third line called enable line.

Give an example of one address microprocessor?
8085 is a one address microprocessor.

In what way interrupts are classified in 8085?
In 8085 the interrupts are classified as Hardware and Software interrupts.

What are Hardware interrupts?
TRAP, RST7.5, RST6.5, RST5.5, INTR.

What are Software interrupts?
RST0, RST1, RST2, RST3, RST4, RST5, RST6, RST7.

Which interrupt has the highest priority?
TRAP has the highest priority.

Name 5 different addressing modes?
Immediate, Direct, Register, Register indirect, Implied addressing modes.

How many interrupts are there in 8085?
There are 12 interrupts in 8085.

What is the RST for the TRAP?
RST 4.5 is called as TRAP.

In 8085 which is called as High order / Low order Register?
Flag is called as Low order register & Accumulator is called as High order Register.

DIGITAL ELECTRONICS TECHNICAL-INTERVIEW QUESTIONS
-----------------------------------------------------------------------

What is the difference between a Flip-Flop and a Latch?

What is race around condition?

What is the VHF,UHF Frequency ranges?

What is Inter signal interference?

What is the difference between a synchronous and asynchronous circuit?Which is better?

What is the significane of excess 3 code?Explain Self-complimenting property?

What is D-FF?

What are the different types of power amplifiers?

What is meant by Companding?

What is the basic difference between counters and registers?

What is a multiplexer?

How can you convert an SR Flip-flop to a JK Flip-flop?

How can you convert a JK Flip-flop to a D Flip-flop?

What is Race-around problem? How can you rectify it?

Which semiconductor device is used as a voltage regulator and why?

Explain an ideal voltage source?

Explain zener breakdown and avalanche breakdown?

What are the different types of filters?

What is the need of filtering ideal response of filters and actual response of filters?

What is sampling theorem?

What is impulse response?

Explain the advantages and disadvantages of FIR filters compared to IIR counterparts.

What is CMRR?

Explain half-duplex and full-duplex communication?

Which range of signals is used for terrestrial transmission?

Why is there need for modulation?

Which type of modulation is used in TV transmission?

Why we use vestigial side band (VSB-C3F) transmission for picture?

When transmitting digital signals is it necessary to transmit some harmonics in addition to fundamental frequency?

For asynchronous transmission, is it necessary to supply some synchronizing pulses additionally or to supply or to supply start and stop bit?

BPFSK is more efficient than BFSK in presence of noise. Why?

What is meant by pre-emphasis and de-emphasis?

Explain 3 dB cutoff frequency? Why is it 3 dB, not 1 dB?

Explain ASCII, EBCDIC?