1. Differentiate Zener breakdown from avalanche breakdown?

Zener Breakdown Avalanche breakdown

1.This occurs at junctions which being

heavily doped have narrow depletion

layers

2. This breakdown voltage sets a

very strong electric field across

this narrow layer.

3. Here electric field is very strong

to rupture the covalent bonds

thereby generating electron-

hole pairs. So even a small

increase in reverse voltage is

capable of producing large

number of current carriers. ie

why the junction has a very low

resistance. This leads to Zener

breakdown.

1. This occurs at junctions which

being lightly doped have wide

depletion layers.

2. Here electric field is not strong

enough to produce Zener

breakdown.

3. Her minority carriers collide

with semi conductor atoms in

the depletion region, which

breaks the covalent bonds and

electron-hole pairs are

generated. Newly generated

charge carriers are accelerated

by the electric field which

results in more collision and

generates avalanche of charge

carriers. This results in

avalanche breakdown.

2. State the principle of operation of SCR?

A silicon controlled rectifier is a semi conductor device that acts as a true

electronic switch. It can change alternating current in to direct current and at

the same time it can control the amount of power fed to the load. Thus SCR

combines the features of a rectifier and a transistor.

3. Distinguish pinch off and cut off in FET?

Pinch off voltage – It is the minimum drain-source voltage at which the drain

current essentially becomes constant.

Cut-off voltage – It is the gate source voltage where the channel completely cut

off and the drain current becomes zero.

4. Distinguish CB, CE, CC configurations in Transistors?

Common base configuration - If the base terminal is connected common to the

input and output , it is called common base. The input is fed between the emitter

and base and the out put between the collector and base.

CE configuration – If the emitter is common to both input and output , it is

called CE configuration. Here input is applied between base and emitter and

output is taken from collector and emitter.

CC configuration – If the collector is common to both input and output , it is

called CC configuration. Here input is applied between base and collector and

output is taken from emitter and collector.

5. Discuss the applications of SCR?

In many applications SCR is used as a power control device. The common

applications includes

1. Relay control

2. Regulated power supplies

3. Static switches

4. Motor control

5. Inverters

6. Battery chargers

7. Heater control

8. Phase control

6. What is a Thermistor?

Thermistor is a combination of thermal and resistance.

A thermistor is a resistance with definite thermal characterisics.

Thermistors are widely used for temperature compensation. ie cancelling the

effect of temperature, liquid level, gas flow etc.

Thermistors are made in the shape of beads, probes, discs, washers etc.

7. Explain Tunneling principle?

The tunnel diode is PN junction device, which operates in certain regions of its

IV characteristics by the quantum mechanical tunneling of electrons through the

potential barrier of the junction.The tunneling process for reverse current is

essentially the zener effect, although negligible reverse bias is needed to initiate

the process in tunnel diodes.It is also called Esaki diode.

8. What the applications of Tunnel diode?

1. High speed switching circuits

2. Logic circuits

9. Define αααα and ββββ in a transistor?

αααα - current amplification factor

It is the ratio of output current to input current. In a common base connection,

The ratio of change in collector current to the change in emitter current at

constant collector-base voltage VCB is known as current amplification factor.ie,

αααα = ∆∆∆∆Ic/∆∆∆∆IE at constant VCB

ββββ - Base current amplification factor

In a common emitter connection, The ratio of change in collector current to the

change in base current is known as base current amplification factor. ie,

ββββ = ∆∆∆∆Ic/∆∆∆∆IB

10. Name the different types of Negative feedback. What are their

characteristics?

1. Negative current series feedback

2. Negative current shunt feedback

3. Negative voltage series feedback

5. Negative voltage shunt feedback

Characteristics

1. Higher fidelity

2. Higher stabilized gain

3. Increased bandwidth

4. Less amplitude distortion

4. Less harmonic distortion

5. Less frequency distortion

6. Less phase distortion

10. Reduced noise.

11. What are the different types of interrupts?

a. Hardware

b. Software

Hardware interrupts- The interrupts where the CPU pins are used to receive

interrupt requests , are called hardware interrupts.

Software interrupts – This interrupt is caused by the execution of the

instruction. These are special instructions supported by the microprocessor.

12. What are the types of hardware interrupts?

� TRAP

� RST 7.5

� RST 6.5

� RST 5.5

� INTR

13. Define PIV?

It is the maximum reverse voltage that a diode can withstand without destroying

the junction.

14. What is a Ripple factor? What is its value for a half wave and Full wave

rectifier?

The ratio of r.m.s value of a.c component to the d.c component in the rectifier

output is known as ripple factor.It decides the effectiveness of the rectifier.

Ripple factor = r.m.s value of a.c component

r.m.s value of d.c component

For half wave rectifier,

Irms = Im/2 ; Idc = Im/ππππ

Ripple factor = ΓΓΓΓ( Im/2 / Im/ΠΠΠΠ )2

– 1 = 1.21

For full wave rectifier,

Irms = Im/ ΓΓΓΓ2 ; Idc = 2Im/ππππ

Ripple factor = ΓΓΓΓ( Im/ ΓΓΓΓ2 / 2 Im/ΠΠΠΠ )2

– 1 = 0.48

14. How transistor amplifies?

When a weak a.c signal is given to the base of the transistor, a small base

current starts flowing. Due to transistor action, a larger (ββββ times the base

current) a.c current flows through collector load Rc. As the value of Rc is quite

high, a large voltage appears across Rc. Thus a weak signal applied in the base

circuit appears in amplified form in the collector. In this way it amplifies the

signal.

15. Classification of Transistor Amplifiers?

The transistor amplifiers are classified as

a. According to use: These includes voltage amplifiers and power

amplifiers.

b. According to frequency capabilities: These includes audio amplifiers,

radio frequency amplifiers etc.

c. According to coupling methods: These includes RC coupled

amplifiers, Transformer Coupled amplifiers etc.

d. According to mode of operation:These includes class A, class B, Class

C amplifiers. Class A amplifier one in which collector current flows

for the entire a.c signal. Class B amplifier is one in which collector

current flows for half cycle of input a.c signal.Class C amplifier is one

in which collector current flows for less than half cycle of a.c signal.

16. What is a multi-stage amplifier?

A transistor circuit containing more than one stage of amplification is known as

multi-stage amplifier. Here output of one stage is connected to the input of

second stage through coupling device.

17. What is the relation between αααα and ββββ?

ββββ = ∆∆∆∆Ic / ∆∆∆∆IB

αααα = ∆∆∆∆Ic / ∆∆∆∆IE

IE = IB +Ic

∆∆∆∆IE = ∆∆∆∆IB +∆∆∆∆Ic

∆∆∆∆IB = ∆∆∆∆IE - ∆∆∆∆Ic

Substituting the value of ∆∆∆∆IB in exp(1), we get,

ββββ = ∆∆∆∆Ic / ∆∆∆∆IE - ∆∆∆∆Ic

Dividing the numerator and denominator of R.H.S by ∆∆∆∆IE, we get,

ββββ = αααα / 1 - αααα

18. What is microprocessor?

It is a program controlled semi conductor device (IC), which fetches,

decodes and execute instructions.

19. What are the basic units of microprocessor?

The basic units or blocks of microprocessor are ALU, an array of

registers and control unit.

20. What is a bus?

Bus is a group of conducting lines that carries data, address and

control signals.

21. Why data bus is bi-directional?

The microprocessor is to fetch (read) the data from memory or input

device for processing and after processing it has to store (write) the data to

memory or output devices. Hence the data bus is bi-directional.

22. Why address bus is uni-directional?

The address is an identification number used by the microprocessor to

identify or access a memory location or input/output device. It is an output

signal from the processor. Hence the address bus is unidirectional.

23. Define machine cycle?

Machine cycle is defined as the time required to complete one

operation of accessing memory input/output, or acknowledging an external

request. This cycle may consists of three to six T-states.

24. Define T-state?

T-state is defined as one subdivision of operation performed in one

clock period. These subdivisions are internal states synchronized with the system

clock, and each T-state is precisely equal to one clock period.

25. What is an instruction cycle?

The sequence of operations that a processor has to carry out while

executing the instruction is called instruction cycle. Each instruction cycle of

processor contains a number of machine cycles.

26. What is fetch and execute cycle?

The instruction cycle is divided in to fetch and execute cycles. The

fetch cycle is executed to fetch the opcode from memory. The execute cycle is

executed to decode the instruction and to perform the work instructed by the

instruction.

27. List the flags of 8085?

There are five flags in 8085.They are sign flag, zero flag, auxiliary

carry flag, parity flag and carry flag.

28. What does memory-mapping mean?

The memory mapping is the process of interfacing memories to

microprocessor and allocating addresses to each memory locations.

29. Difference between memory mapped I/o and I/O mapped I/o?

Memory mapped I/O I/O mapped I/O

1. In this device address is 16- bit. Thus

Ao to A15 lines are used to generate

the device address

1. In this device address is 8-bit. Thus

Ao to A7 or A8 to A15 lines are used to

generate device address.

2. MEMR and MEMW control signals

are used to control read and write I/O

operations.

2. IOR and IOW control signals are

used to control read and write I/O

operations.

3. Instructions available are

LDA,STA,MOV R,M , ADD M etc

3. Instructions available are IN and

OUT.

4. Data transfer is between any register

and I/O device.

4. Data transfer is between

accumulator and I/O device.

5. Decoding 16-bit address may 5. Decoding 8-bit address will require

require more hardware. less hardware.

30. Describe the function of the following pins in 8085?

a) READY b) ALE c) IO/M d) HOLD e)SID and SOD

READY – It is used by the microprocessor to sense whether a peripheral is

ready or not for data transfer. If not, the processor waits. It is thus used to

synchronize slower peripherals to the microprocessor.

ALE – In 8085 , ADo to AD7 lines are multiplexed and lower half of address (Ao

to A7) is available only during T1 of the machine cycle. The latching of lower

half address from the multiplexed address lines by using ALE signal.

IO/M - indicates whether I/O operation or memory operation is being carried

out.

HOLD – This signal indicates that another master is requesting for the use of

address bus, data bus and control bus.

SID(Serial Input Data) – This input signal is used to accept serial data bit by bit

from the external device.

SOD(Serial Output Data) – This is an output signal which enables the

transmission of serial data bit by bit to the external device.

31. Comparison between full address decoding and partial address decoding?

Full Address Decoding Partial Address decoding

1. All higher address lines are decoded

to select the memory or I/O device.

1. Few higher address lines are

decoded to select the memory or I/O

device.

2. More hardware is required to design

decoding logic.

2. Hardware required to design

decoding logic is less and sometimes it

can be eliminated.

3. Higher cost for decoding circuit. 3. Less cost for decoding circuit.

4. No Multiple addresses. 4. It has a advantage of multiple

addresses.

5. Used in large systems 5. Used in small systems

32. What is ALE?

The ALE (Address latch enable) is a signal used to demultiplex the

address and data lines using an external latch. It is used to enable the external

latch.

33. Where is the READY signal used?

READY is an input signal to the processor, used by the memory or

input/output devices to get extra time for data transfer or to introduce wait

states in the bus cycles.

34. What is program counter? How it is useful in program execution?

The program counter keeps track of program execution. To execute

a program the starting address of the program is loaded in program counter.

The PC sends out an address to fetch a byte of instruction from memory and

increments its content automatically.

35. Define opcode and operand?

Opcode(operation code) is the part of an instruction that identifies a

specific operation. Operand is a part of instruction that represents a value on

which the instruction acts.

36. How the 8085 processor differentiates a memory access and I/O access?

The memory access and I/O access is differentiated using IO/M

signal. The 8085 processor asserts IO/M low for memory operation and high for

I/O operations.

37. Why interfacing is needed for I/O devices?

Generally I/O devices are slow devices. Therefore the speed of I/O

devices does not match with the speed of microprocessor. And so an interface is

provided between system bus and I/O devices.

38. What is interrupt I/O?

If the I/O device initiate the data transfer through interrupt then the

I/O is called interrupt driven I/O.

39. What is a port?

The port is a buffered I/O, which is used to hold the data

transmitted from the microprocessor to I/O devices and vice versa.

40. What is synchronous data transfer scheme?

For synchronous data transfer scheme, the processor does not

check the readiness of the device after a command have been issued for

read/write operation. For this scheme the processor will request the device to get

ready and then read/write to the device immediately after the request.

41. What is asynchronous data transfer scheme?

In asynchronous data transfer scheme, first the processor sends a

request to the device for read/write operation. Then the processor keeps on

polling the status of the device. Once the device is ready, the processor executes a

data transfer instruction to complete the process.

42. What is scanning in keyboard and what is scan time?

The process of sending a zero to each row of a keyboard matrix

and reading the columns for key actuation is called scanning. The scan time is

the time taken by the processor to scan all the rows one by one starting from

first row and coming back to the first row again.

43. What are the tasks involved in keyboard interface?

The tasks involved in keyboard interfacing are sensing a key

actuation, Debouncing the key and generating key codes( Decoding the key).

These tasks are performed software if the keyboard is interfaced through ports

and they are performed by hardware if the keyboard is interfaces through 8279.

44. How a keyboard matrix is formed in keyboard interface using 8279?

The return lines, RL0 toRL7 of 8279 are used to form the columns of

keyboard matrix. In decoded scan lines SL0 t0SL3 of 8279 are used to form the

rows of keyboard matrix. In encoded scan mode, the output lines of external

decoder are used as rows of keyboard matrix.

45. What is GPIB?

GPIB is the General Purpose interface Bus. It is used to interface the

test instruments to the system controller.

46. Comparison between full address decoding and Partial address decoding?

Full address decoding Partial address decoding

1. All higher address lines are decoded

to select the memory or I/O device.

1. Few higher address lines are

decoded to select the memory or I/O

device.

2. More hardware is required to design

decoding logic.

2. Hardware required to design

decoding logic is less and sometimes it

can be eliminated.

3. Higher cost for decoding circuit. 3. Less cost for decoding circuit.

4. No multiple addresses. 4. It has a disadvantage of multiple

addresses. (Shadow addresses)

5. Used in large systems. 5. Used in small systems.

47. What is the difference between SHLD and LHLD?

SHLD- Store HL register pair in memory.

This instruction is used to store the contents of H and L register directly

in to memory.

LHLD- Load HL register pair from memory.

This instruction copies the contents of memory location given with in the

instruction in to the L register and the contents of next memory location in to the

H register.

48. What is the difference between STAX and LDAX?

STAX rp – Store the contents of Accumulator register (A) in memory location

whose address is specified by BC or DE register pair.

LDAX rp – Load Accumulator register (A) with the contents of memory location

whose address is specified by BC or DE register pair.

49. Write an assembly language program to transfer data from memory block

B1 to memory block B2?

MVI C,0AH; Initialize counter

LXI H, 2200H; Initialize source memory pointer

LXI D, 2300H; Initialize destination memory pointer

Loop: MOV A,M; Get byte from source memory block

STAX D; Store byte in the destination memory block

INX H; Increment source memory pointer

INX D; Increment destination memory pointer

DCR C; Decrement counter

JNZ Loop ; If counter ≠≠≠≠ 0 repeat

HLT

50. What are the types of branching instructions?

1. Jump instructions

2. Call and Return instructions

3. Restart instructions

51. Write an assembly language program to add 2 BCD numbers?

LXI H,2200H; Initialize pointer

MOV A,M ; Get the first number

INX H; Increment the pointer

ADD M ; Add two numbers

DAA ; Convert HEX to valid BCD

STA 2300; store the result

HLT

52. Explain the instruction LXI rp,data (16)?

LXI rp, data(16) – Load 16 –bit immediate data to specified register pair

or stack pointer. The rp is 16 – bit register pairs such as BC, DE, HL or stack

pointer.

53. Write the difference between LDA and STA instruction?

LDA – Load data in to Accumulator register(A) directly from the address

specified with in the instruction.

STA – Store the contents of Accumulator register(A) to the address specified

with in the instruction.

54. What are the types of rotate instructions?

RLC – Rotate Accumulator Left

RRC- Rotate Accumulator Right

RAL – Rotate Accumulator Left through Carry

RAR - Rotate Accumulator Right through Carry

15. What is meant by stabilization of operating point?

The process of making operating point independent of temperature

variations or changes in a transistor parameter is known as stabilization.

55. What is Thermal runaway?

The self destruction of an unstabilised transistor is known as thermal runaway.

58. What is Accumulator Register?

It is an 8 – bit register. It holds a source operand and receives the

result of the arithmetic instructions (Addition, Subtraction, Multiplication and

Division)

59. What is the difference between SISO and SIPO?

The serial in serial out shift register accepts data serially -ie one bit at a time on a

single line. It produces the stored information on its output also in serial form.

In Sserial in parallel out, the data bits are entered serially (right most bit first) and

once the data bits are stored, each bits apperas on its respective output line, and all

bits are available simultaneously, rather than one bit at a time basis as with serial

output.

60. What are the applications of shift registers?

a) Time derlay - SISO register can be used to provide a time delay from input to

output ie a function of both number of stages in the register and the clock

frequency.

b) USRT ( Universal synchronous Receiver Transmitter)

c)Keyboard encoder - used as a ring counter

61. What is the function of shift register?

Shift register consists of an arrangement of flip-flops used for storage and transfer

of data in a digital system.

62. What are the characteristics of digital Ic's?

1. Speed of operation

2. Power dissipation

3. Fan-out

4. current and voltage parameter

5. Noise immunity

6. Operating temperature

7. Power supply requirements

8. Flexibility available

63. Convert the binary number 101101.10101 to decimal?

Multiply each digit by its weight

Ans:45.65625

64. Convert decimal number 247 to octal?

Divide the number by 8. Take remainder as output.

Ans:367

65. Convert decimal fraction .5100098 to octal?

Multiply the fraction by 8. Take the integer part as output.

Ans:(.4651)

66. Convert ocatal number 736 to binary?

By replacing each octal digit by its equivalent binary.

Ans:111 011 010

67. Convert the hexa decimal number to decimal?

Multiply each digit by its weight.

Ans: 58.1836

68. Convert the the binary number 101101110.11001010011 to hexa decimal?

Split the numbers to 4 bit groups, then write the corresponding hex digit.

Ans:0010 1101 1110 . 1100 1010 0110

2 D E C A 6

69. Comparison between analog and digital systems?

Analog systems Digital systems

It has continous set of values. 1.Discrete set of values

2. It involve frequency and time domain

concepts

3. Complicates circuit analysis

4. Effect of fluctuations in the electrical

characteristics of the component,

temperature and noise are high

5. Speed is low

2. It involves Boolean algebra

3. Very simple

4. Here these components are very small.

5. Highly reliable and high speed used in

computers,calculators etc.

70. What are the types of multivibrators?

a)Monostable multivibrator

b)Astable multivibrator

c)Bi-stable multivibrator

71. What is a counter? What are the types of counter?

A circuit used foe counting the pulses are called counters.

Two types.

1. Synchronous counter

2. Asynchronous counter

72. What is the differnce between synchronous and asynchronous counters?

In the case of asynchronous counters, all the flipflops are not clocked simultanously.

eg: Ripple counter

In synchronous counters, all the flip-flops are clocked simultaneously.

eg: Ring counter

73. What is the function of adders?

It is used not only in computers but also in many types of digital systems in which

numerial data are processed.

Two types

1. Half adder

2. Full adder

74. What is the difference between multiplexer and demultiplexer?

Multiplexer (MUX) is a device that allows digital information from several sources

to be routed on to a single line for transmission over that line to a common

destination. The basic multiplexer has several data input lines and a single output

line.It also has a data-select inputs,which permit digital data on any one of the input

to be switched to the output line. Multiplexers are also called data selectors.

Demultiplexer (DEMUX) basically reverses the multiplexing action. It takes digital

information from one line and distributes it to a given number of output lines. It is

also called data distributor.

75. Differentiate encoder and decoder?

The basic function of decoder is to detect the presence of a specified combination of

bits on its inputs and to indicate the presence of that code by a specified output level.

Ie decoders are used to decode binary states of inputs.

Encoder is a combinational logic circuit that performs reverse order decoder

function. It accepts active level on one of its inputs representing a digit, such as a

decimal or octal digit , and converts it to a coded output, such as a BCD or Binary.

Encoders can also be devised to encode various symbols and alphabetic characters.

The process of converting from familiar symbols or numbers to a coded format is

called encoding.

76. Define Flip-flops?

Flip-flops are synchronous bi-stable devices , synchronous means that the output

changes state only at a specified point on a triggering input called clock(CLK) ,

which is defined as a control input, C; ie changes in the output occur in

synchronization with the clock. The edge-Triggered flip-flop changes state either at

the positive edge (rising edge) or at the negative edge (falling edge) of the clock pulse

and is sensitive to the inputonly at this transition of the clock.

77. Draw the Truth table of SR flip-flop?

Inputs

S R CLK

Outputs

Q Q

Comments

0 0 X

0 1 ↑↑↑↑

1 0 ↑↑↑↑

1 1 ↑↑↑↑

Qo Q o

0 1

1 0

? ?

No change

RESET

SET

Invalid

↑↑↑↑ - Clock transition LOW or HIGH

Qo - Output level prior to clock transition

X – irrelevant (“don’t care”)

78. Draw the Truth table of JK flip-flop?

Inputs

J K CLK

Outputs

Q Q

Comments

0 0 X

0 1 ↑↑↑↑

1 0 ↑↑↑↑

1 1 ↑↑↑↑

Qo Q o

0 1

1 0

Q o Qo

No change

RESET

SET

Toggle

↑↑↑↑ - Clock transition LOW or HIGH

Qo - Output level prior to clock transition

79. What are the steps involved in the fabrication of monolithic IC’s?

a)Wafer preparation

b)Epitaxial growth

c)Oxidization

d)Photolithiography process

e)Isolation diffusion

f)Pre ohmic etch

g)Metallization

h)Circuit probing

i)Scribing and separation into chips

j)Mounting and packing

j)Encapsulation

80. Describe briefly about floppy disks?

-These are commonly used as secondary storage and back up memories. They

are also called diskettes.

-These disks are very thin and flexible., hence it is called floppy.

They are very small,inexpensive and convenient.

They are removable diska.

The popular sizes of floppy disks are 5.25” and 3.5”.

It is a surface device.

81. Describe briefly about Hard disks?

These are made up of aluminium or other metals or metal alloys instead of

plastic.

It has high speed ie 3600rpm.

It is more stable as it is rigid and contained in the dust-free environment.

Its track and bit densities are much higher compared to floppy disks.

Its data transfer rate is 10MB/sec.

The average access time is from 25-50ms.

The reliability of data is 1 in 1011

.

82. What are the advantages of magnetic memory?

It is a non-volatile memory without any moving part.

It has semi random access and nondestructive read out property.

It has high reliability

High data density

Small size

Light weight

Limited power dissipation

Used as a mass storage device.

83. Compare RAM and ROM?

RAM ROM

1.Volatile memory.The information

written in to it is retained as long as

the power supply is on.

2. The information stored is not

permanent.

3. not cheaper compared to RAM.

4. It is Read and Write memory

1.Non-volatile memory.ie the

information stored in it is not lost even

if the power supply goes off.

2. Used for permanent storage of

information.

3. cheaper.

4. It is a Read only memory.

84. What are the steps in memory interfacing?

1. be able to select the chip.

2. identift the register

3. enable the appropriate buffer

85. What are the interrupts in 8085?

TRAP

RST 7.5

RST 6.5

RST 5.5

INTR

86. What are the segment registers in 8086?

1. Code segment register

2. Data segment register

3. Stack segment register

4. Extra segment register

87. What is vectored and non-vectored interrupt?

When an interrupt is accepted, if the processor control branches to

a specific address defined by the manufacturer then the interrupt is called

vectored interrupt. In Non-vectored interrupt there is no specific address for

storing the interrupt service routine. Hence the interrupted device should give

the address of the interrupt service routine.

88. List the software and hardware interrupts of 8085?

Software interrupts : RST 0,RST 1,RST 2,RST 3,RST 4,RST 5,RST 6,RST 7

Hardware interrupts : TRAP,RST 7.5,RST 6.5,RST 5.5, INTR.

89. What is TRAP?

The TRAP is a non-maskable interrupt of 8085. It is not disabled by

processor reset or after recognition of interrupt.

90. How clock signals are generated in 8085 and what is the frequency of the

internal clock?

The 8085 has the clock generation circuit on the chip but an external

quartz crystal or LC circuit or RC circuit should be connected at the pins X1

andX2. The maximum internal clock frequency of 8085 is 3.03MHz.

91. Define stack?

Stack is a sequence of RAM memory locations defined by the

programmer.

92. What is USART?

The device which can be programmed to perform Synchronous or

Asynchronous serial communication is called USART (Universal Synchronous

Asynchronous Receiver Transmitter). Eg: INTEL 8251

93. What is scanning in keyboard and what is scan time?

The process of sending a zero to each row of a keyboard matrix

and reading the columns for key actuation is called scanning. The scan time is

the time taken by the processor to scan all the rows one by one starting from

first row and coming back to the first row again.

94. What are the different types of Address decoding Techniques?

Absolute decoding/Full decoding

Linear decoding/Partial decoding

95. Define Addressing modes? What are the types of Addressing modes?

It specify the ways in which data are processed.

1. Immediate Addressing modes

2. Register Addressing modes

3. Direct Addressing modes

4. Register Indirect Addressing modes

5. Implied Addressing modes.

96. What are the types of instruction formats?

1-bte instruction

2-bte instruction

3-bte instruction

97. Explain the different stages of a power amplifier?

It is used to amplify a weak signal until sufficient power is available to operate a

loud speaker or other output device. It has 3 stages.

1)voltage amplification stage

2)Driver stage

3)Output stage.

Eg: Push-pull amplifier

98. Why we use printers? What are the types of printers?

Printers are commonly used output device. They provide information in a

permanent readable form. They produce printed output of results, programs,

and data.

Depend up on the technology used in their manufacture, printers are classified

in to

1. Impact printers

2. Non-impact printers

99. What is the use of Memory refresh register in Z-80?

Used to refresh dynamic memories.

100. What is VMA?

- virtual memory address

101. Define Transistor Biasing?

The proper flow of zero signal collector current and the maintenance of proper

collector-emitter voltage during the passage of signal is known as transistor biasing.

Essay Questions

1. Explain the different stages of a power amplifier? What are the

classifications of power amplifier?

It is used to amplify a weak signal until sufficient power is available to operate a

loud speaker or other output device. It has 3 stages.

1)voltage amplification stage

2)Driver stage

3)Output stage.

Eg: Push-pull amplifier

Classifications

Class A power amplifier

Class B power amplifier

Class C power amplifier

2. What are the steps involved in the fabrication of monolithic IC’s?

a)Wafer preparation

b)Epitaxial growth

c)Oxidization

d)Photolithiography process

e)Isolation diffusion

f)Pre ohmic etch

g)Metallization

h)Circuit probing

i)Scribing and separation into chips

j)Mounting and packing

j)Encapsulation

3. Give the construction details and explain the working of FET showing its

characteristics?

• Circuit diagram

• Theory of operation

Two types

1.JFET

2.MOSFET

Characteristics

1. Drain characteristics

2. Transfer characteristics

4.Compare CB,CE,CC with respect to i/p resistance,gain,o/p resistance?

Distinguish CB, CE, CC configurations in Transistors?

• Circuit dgms

• Input characteristics

• Output characteristics.

5.Define feed back amplifier? What are the types of feed back amplifier?

1. Positive feed back

Negative feedback – a) . Negative current series feedback

b). Negative current shunt feedback

c). Negative voltage series feedback

d). Negative voltage shunt feedback

6. Why we use printers? What are the types of printers?

Printers are commonly used output device. They provide information in a

permanent readable form. They produce printed output of results, programs,

and data.

Depend up on the technology used in their manufacture, printers are classified

in to

1. Impact printers

2. Non-impact printers

7.Explain DMA data transfer scheme with example?

a. Diagram

b. Eg: Intel 8237 (DMA controller) – Pin diagram

- Explanation

8.With a neat block diagram, explain the working of Transformer coupled

amplifier? Derive its gain expression?

• Diagram

• Operation

• Gain expression

9.Draw the diagram of half wave and Full wave rectifiers and explain their

operation. Also compare them?

• Circuit diagrams

• Theory of operation

• Calculate efficiency

10.Draw the circuit diagram of RC coupled amplifier with neat diagram of self

bias circuit and explain the operation. Comment on its low frequency and high

frequency performance?

• Diagram

• Operation

• Frequency curve at low, high and mid frequencies.

11.Why we use multi-vibrators in digital systems?

In digital systems rectangular wave form is most desirable. The generators of

rectangular wave forms are referred to as multi-vibrators.

Three types

1. Astable multi-vibator

2. mono stable multi-vibator

3. bi-stable multi-vibator

7. Draw the circuit diagrams of a 4-bit shift register using flip-flops and

explain?

They are

1. SISO

2. SIPO

3. PISO

4. PIPO

12.What are the drawbacks of Ripple counter? How they can be overcome by

synchronous counters?

Ripple counters are asynchronous counters. The problems are avoided by a

common clock pulse used in synchronous counters.

13.Define filters? What are the types of filters used?

It is a device which removes the a.c component of a rectifier output but allows

the d.c component to reach the load.

Types

1. capacitor filter

2. inductor filter

3. choke input filter

4. capacitor input filter or ππππ filter.

8. Explain the types of counters?

• Sunchronous counters

• Asynchronous counters.

14.Explain the applications of microprocessors in aerospace?

15.Explain the operations of hard disk drive?

• Diagrams

• Explanation

16.Explain serial and Parallel data transfer?

Serial data transfer – Duplex

Half duplex

Full duplex

Eg:USART (Universal synchronous/Asynchronous Receiver Transmitter)

Parallel data transfer – eg: PPI (Programmable peripheral interface)

17.Explain about A/D and D/A converters?

A/D converters

1. Weighted resistor DAC

2. R-2R ladder

3. Inverted R-2R ladder

D/A converters

a)Direct Types

1. Flash type converter

2. Counter type converter

3. Tracking or servo converter

4. Successive approximation type converter

b)Integrating types

1. Charge balancing ADC

2. Dual slope ADC

18.With Neat diagram, explain the Architecture of 8085?

� Block diagram

� Explaination

19. Explain the instruction sets of 8085?

• Data transfer instructions

• Arithmetic instructions

• Logical instructions

• Branching instructions

• Machine control instructions

20. Explain about memory interfacing?

1. EPROM memory

2. RAM memory

21. .With Neat diagram, explain the Architecture of Z-80?

� Block diagram

� Explanation

22. With Neat diagram, explain the Architecture of M 6800?

� Block diagram

� Explanation

23. Write an Assembly language program to find largest number from a given

set of numbers?

• Algorithm

• Program

• Output

24. Write an Assembly language program to sort a set of numbers?

• Algorithm

• Program

• Output

25. Define Addressing modes? What are the types of Addressing modes?

Addressing modes specify the ways in which data are processed.

1. Immediate Addressing modes

2. Register Addressing modes

3. Direct Addressing modes

4. Register Indirect Addressing modes

5. Implied Addressing modes

NOORUL ISLAM COLLEGE OF ENGINEERING

DEPARTMENT OF COMPUTER SCIENCE & ENGINEERING

FIFTH SEMESTER

EC1269 – Microprocessors & Applications

2 MARKS AND 16 MARKS Q & A

Prepared by,

Sinciya. P.O

L/CSE

NICE