7/24/2019 SNIST ET QUESTION PAPER

1/2

SREENIDHI INSTITUTE OF SCIENCE & TECHNOLOGY

Autonomous

Institution

Yamnampet,

Ghatkesar,

H

-

501 301.

F'IRST

MID EXAMII{ATIOI{

2015

CLASS: B. Tech

II Year I-SEM

SIJBJECT:

ELECTRICAL

TECHNOT,OGY

Date

:21.09.2415

(AN)

Branch: ECE(A,B,C,D,E)

TIME:

2 hours

Max

lVlarks:

24

Part

-

A

(ALL

Questions

are

Compulsory)

,1"

Name the

essential

parts

of a DC Machine.

).Write

the applications

of DC shunt and series

motors.

3.

What

is the necessity

of the starter?

4.

What are

different types

of

losses

in dc

machine?

j.

Write the differences between core type and

shelltype

transforrners,

$Draw

the circuit

and

phasor

diagran'l

of ldeal transformer on

noJoad.

Part

-

B

6X1=6

Answer

any THREE out of the

FlVEquestions 3X

6

=

'tB

a@Ctassify

the types of DC

generators

with neat

diagrams.

6

A 4

pole

1500 rpm

dc

generator

has

a lap wound

armature having 24 slots

with 1

0

conductors

per

slot.

lf

flux

per pole

is 0,04weber, calculate

the

generated

emf

in

the

armature.

z..Senvethe

torque equation of dc motors.

-VY{ZS0V

dc shunt motor

takes

40A at full

load,

find the

back

emf on full load

if Ra

and

Rsh

are 0.254 and 250O respectively.

3. a)-Deiive an expression

for emf induced in 1-phase transformer.

b) A 440V,

50Hz

1-phase transformer has 400 turns

on

primary

and

100

turns on

secondary. Tlre area of cross

section of

magnetic

core

is 65 sq.cm.

determine emf

induced in

secondary and maximum

value of flux density.

4 a) Draw and explain Open Circuit Characteristics

of dc shunt

generator

b) Explain speed control

of

dc shunt motor by armature voltage control

rnethod.

c)

Explain

the operation

of

transformer,

5 a) Describe the 3-point

starter with neat diagram.

b)

Explain

load

characteristics

of dc series

generator.

c) A25O1125V, 50Hz

1-phase

transformer has

maximurn flux density

is 1.4 tesla and

area

of

cross section of magnetic core is 0.032

sq.mt. calculate induced emf

per

turn,

7/24/2019 SNIST ET QUESTION PAPER

2/2

SREENIDHI

INSTITUTE

Autonomous

lnstitution

Yalnnampet,

Ghatkesar,

Hyderabad

_

501

g01.

qECqNDrvrrDExAm

CLASS:

II

-B.Tech

I-SEM

Branch:

ECE

(A,

B,

C&D)

TIME:

2

hours

UBJECT:

ET

Date

:

25

.11 .2015

(AI.{)

Max

Marks:

24

part

-

A

(Compalsory

Only

Short

answers)

6X1=6

l.

Give applications

of

induction

moton

2'

Explain

Faradoys

laws

of

electro

magnetic

induetion

with

applications?

3.

Give

applications

of,universal

motor?

4.

Why

siugle

phase

induction

motor

is

not

self

starting?

5.

lVhat

is

hunting?

6.

What

is purpose

of

Tacho

meter?

Part

-

B

3X6=19

_._.-a,,_-

(SuO199 iye

Type

euestions)

-

Answer?ny

THREE

out

of

the

fivg{qesllo11

"/2{Wnlte

a

short

note

on

various

methods

for

making

single phase

iuduction-"

'

motor

self

start?

o--

r---v

---'

8'

Explain

b"i*{y

Torque-slip

characteristics

of induction

motorwith

a neat

diagram.

And

also

explain

generating

and

breaking

region?

r

-

9'-

With

a

neat

sketch

explain

construetion

and

working

of

alfernator?

10'

3'

List

out

Differences

between

Squirrel

cage

rotor

ard

Slip

ring

rotor?

-b.'

Write

a

short

uote

on

univensafmotor?

rv, L

+-n

s0Hz

three

phase.iaduction

motor

is

running

at 14r0rpm.

Calculate

slip

speed

and

sHp

of

motor.

11.

,+rD?y

the

consf,ructional

diagram

of stepper

motor.

'

b>

A

Volt

meter

gives

l20occiHations

per

minute

when

it

is

connected

to

"'

rotor

of

three phase

50Hz

induction

motor.

Calculate

op"""d;;;io"

of

motor.

*g_Nrite

a short

note

on

AC

series

motor.

'i,-

*

i 1--