Pages

Wednesday, October 30, 2013

The equivalent circuit shown represents a / an ................. Gate.

The equivalent circuit shown represents a / an ................. Gate.

A. Ex-OR
B. NOT
C. OR
D. AND



Answer:

It is an AND gate because lamp glows only when both switches are closed.


Simple tips to remember the phasor relationship b/W voltage and current for resistor , inductor and capacitor

Simple tips to remember the phasor relationship b/W voltage and current for resistor , inductor and capacitor

Remember the word "CIVIL"

In capacitor I leads V

In inductor I lags V




for pure capacitor I leads V by 90 deg


for pure inductor I lags V by 90 deg


for pure resistor I inphase with V (0 deg)







Tuesday, October 29, 2013

A resistance 5ohm inductance 0.02 H and capacitor 5 uf are connected in series.find the value of power factor at resonance condition.

A resistance 5ohm inductance 0.02 H and capacitor 5 uf are connected in series.find the value of power factor at resonance condition.

a. 0.6
b. 0.8
c. 0.9
d. 1

Answer:

at resonance condition,XL=XC and therefore Z=R, hence for pure resistive circuit pf will be unity.

Thursday, October 24, 2013

One of the parts ( A, B, C, D ) in the sentence given below contains an ERROR. Which one of the following is INCORRECT

GATE-EE-2012
***********

One of the parts ( A, B, C, D ) in the sentence given below contains an ERROR. Which one of the following is INCORRECT ?

I requested that the should be given the driving test today instead of tomorrow.

A. requested that

B. should be given

C. the driving test

D. instead of tomorrow


Answer:

B.should be given

Wednesday, October 23, 2013

A 1-hp motor draws 1000 watts. What is its efficiency ?

A 1-hp motor draws 1000 watts. What is its efficiency ?


Answer:

Efficiency = output / input

Therefore, efficiency = 746 / 1000 = 0.746

Efficiency = 74.6 % 

Monday, October 21, 2013

Anna University- Tamil Nadu State Level Placement Programme” (TNSLPP) 2013-14- CTS

Posted Date: 22nd October 2013

Company Name: M/s Cognizant Technology Solutions

Organised By: Centre for University Industry Collaboration (CUIC), Anna University, Chennai

Program Name: Tamil Nadu State Level Placement Programme” (TNSLPP) 2013-14

About Program: Anna University, Chennai is organizing “Tamil Nadu State Level Placement Programme” (TNSLPP) 2013-14, for the Present Final Year (2014 Passing Out Students) studying in Self Financing Engineering Colleges of Tamil Nadu.

Date of placement Program: 26th and 27th October 2013

Qualification: B.E/B.Tech/MCA

Eligibility Criteria:
  • 2014 passing out candidates
  • B.E/B. Tech (CSE, ECE, EEE, EIE, ICE & IT) & PG (MCA)
  • Minimum 75.00% in 10th & 12th
  • CGPA of 8.00 and above
  • No standing arrears allowed at the time of recruitment process
  • Strong Written and Oral Communication Skills
  • Flexibility to work in Shifts and in any Cognizant Location
  • Open only to Indian Nationals
Interview Process:
  • Group Discussion for all the Candidates
  • Online Aptitude Test for Shortlisted Candidates
  • Technical & HR Interview
Job Role: Programmer Analyst Trainee

Salary Package: Rs. 3.0 Lakhs per annum

Document to Bring:
  • Students must carry the following for the recruitment process:
  • Four recent Photographs (both ears visible on a light background)
  • Resume (maximum of 2 pages)
  • Photocopy of all academic records and
  • College ID Card
Registration Fee: All the eligible candidates have to pay one time Registration fee of Rs. 750/- (Rupees Seven hundred and fifty only) each in the form of Demand draft drawn in favour of “The Director, CUIC, Anna University” payable at Chennai.

To View Advertisement and  Download Application Form: Clickhere

Venue Address:
Mohammed Sathak AJ College of Engineering, 
Rajiv Gandhi Road (OMR) IT-Park Siruseri,
Kancheepuram District - 603 103 
(044 – 27470021 / 23 / 24 / 25 / 26).

For More details:
Dr. T. Thyagarajan
Professor & Director
Mobile: 9444104850

Dr. K. Arunachalam
Deputy Director
Mobile: 9884345564

Dr. S. Bose
Deputy Director
Mobile: 9840277262

Tentative Schedule:
Day1
  • 7.30 a.m. - General Briefing
  • 7.45 a.m. - College-wise Call (Alphabetical Order)
    • Verification of Certificates
    • Issue of TNSLPP Admit Card
    • Affixing the Photograph & Endorsement
  • 8.30 a.m. - Group Discussion
  • 7. 10.00 a.m. - Aptitude Test
  • 3.00 p.m. - Declaration of Test Results
Day 2
  • 8.00 a.m. - Technical and HR Interview
  • 2.30 p.m. - Final Selection
  • 4.00 p.m. - Briefing for the Selected Students by Anna University Officials
  • 4.30 p.m. - Open Session with CTS Executives
List Of Engineering College Students are Eligible Attend Placement Program:

1 A.R. Engineering College
2 Aalim Mohammed Salegh College of Engineering
3 ACT College of Engineering and Technology
4 Adhiparasakthi Engineering College
5 Adhiyamaan College of Engineering (Autonomous)
6 Agni College of Technology
7 Aksheyaa College of Engineering
8 AKT Memorial College of Engineering and Technology
9 Anand Institute of Higher Technology
10 Annai Teresa College of Engineering
11 Annamalaiar College of Engineering
12 Apollo Engineering College
13 Apollo Priyadarshanam Institute of Technology
14 Archana Institute of Technology
15 Arignar Anna Institute of Science and Technology
16 ARM College of Engineering and Technology
17 Arulmigu Meenakshi Amman College of Engineering
18 Arunai College of Engineering
19 Arunai Engineering College
20 Asan Memorial College of Engineering and Technology
21 Balaji Institute of Engineering and Technology
22 Balamani Arunachalam Educational & Charitable Trust’s Group of Inst.
23 Bhajarang Engineering College
24 Bharathidasan Engineering College
25 Chendu College of Engineering and Technology
26 Chennai Institute of Technology
27 Dhaanish Ahmed College of Engineering
28 Dhanalakshmi College of Engineering
29 Dhanalakshmi Srinivasan College of Engineering and Technology
30 DMI College of Engineering
31 Dr. Navalar Nedunchezhiyan College of Engineering
32 Dr. Paul’s Engineering College
33 Easwari Engineering College
34 ER.Perumal Manimekalai College of Engineering
35 ES College of Engineering and Technology
36 GGR College of Engineering
37 GKM College of Engineering and Technology
38 Global Institute of Engineering and Technology
39 Gojan School of Business and Technology
40 Gopal Ramalingam Memorial Engineering College
41 Government College of Engineering – Bargur
42 GRT Institute of Engineering and Technology
43 Idhaya Engineering College for Women
44 IFET College of Engineering
45 Indira Gandhi College of Engineering and Technology for Women
46 Indira Institute of Engineering and Technology
47 J N N Institute of Engineering
48 Jawahar Engineering College,
49 Jaya Engineering College
50 Jaya Suriya Engineering College
51 Jayalakshmi Institute of Technology
52 Jayam College of Engineering and Technology
53 JEI Mathaajee College of Engineering
54 Jeppiaar Engineering College
55 Jerusalem College of Engineering
56 John Bosco Engineering College
57 Kalsar College of Engineering
58 Kanchi Pallavan Engineering College
59 Karpaga Vinayaga College of Engineering and Technology
60 KCG College of Technology
61 Kings Engineering College
62 Krishnasamy College of Engineering and Technology
63 KRS College of Engineering
64 Lakshmi Chand Rajani College of Engineering and Technology
65 Lord Ayyappa Institute of Engineering and Technology
66 Lord Venkateshwaraa Engineering College
67 Loyola – ICAM College of Engineering and Technology
68 Loyola Institute of Technology
69 M R K Institute of Technology
70 Maamallan Institute of Technology
71 Madha Engineering College
72 Madha Institute of Engineering and Technology
73 Magna College of Engineering
74 Maha Barathi Engineering College
75 Mailam Engineering College
76 Meenakshi College of Engineering
77 Meenakshi Sundararajan Engineering College
78 Misrimal Navajee Munoth Jain Engineering College
79 Mohammed Sathak AJ College of Engineering
80 New Prince Shri Bhavani College of Engineering and Technology
81 Oxford College of Engineering
82 P.S.V. College of Engineering and Technology
83 Pallavan College of Engineering
84 Panimalar Engineering College
85 Panimalar Institute of Technology
86 PB College of Engineering
87 Peri Institute of Technology
88 PMR Engineering College
89 Podhigai College of Engineering and Technology
90 Prathyusha Institute of Technology and Mangement
91 Prince Dr. K. Vasudevan College of Engineering and Technology
92 Prince Shri Venkateshwaraa Padmavathy Engineering College
93 PT Lee Chengalvaraya Naicker College of Engineering and Technology
94 R.M.D. Engineering College
95 R.M.K. Engineering College
96 Rajalakshmi Engineering College
97 Rajalakshmi Institute of Technology
98 RMK College of Engineering and Technology
99 Rrase College of Engineering
100 S.A. Engineering College
101 Sakthi Engineering College
102 Sakthi Mariamman Engineering College
103 Sams College of Engineering and Technology
104 Sapthagiri College of Engineering
105 Saraswathy College of Engineering & Technology,
106 Saveetha Engineering College
107 Shree Motilal Kanhaiyalal Fomra Institute of Technology
108 Shreenivasa Engineering College
109 Shri Andal Alagar College of Engineering
110 Shri Sapthagiri Institute of Technology
111 SKP Engineering College
112 SKP Institute of Technology
113 SKR Engineering College
114 Sree Krishna College of Engineering
115 Sree Sastha College of Engineering
116 Sree Sastha Institute of Engineering and Technology
117 Sri Aravindar Engineering College
118 Sri Balaji Chockalingam Engineering College
119 SRI College of Engineering and Technology
120 Sri Krishna College of Engineering
121 Sri Krishna Engineering College
122 Sri Krishna Institute of Technology
123 Sri Lakshmi Ammal Engineering College
124 Sri Muthukumaran Institute of Technology
125 Sri Ramana Maharishi College of Engineering
126 Sri Ramanujar Engineering College
127 Sri Rangapoopathi College of Engineering
128 Sri Sai Ram Institute of Technology
129 Sri Sairam Engineering College
130 Sri Sivasubramaniya Nadar College of Engineering
131 Sri Venkateswara College of Engineering and Technology
132 Sri Venkateswara Institute of Science and Technology
133 Sri Venkateswaraa College of Technology
134 Srinivasa Institute of Engineering and Technology
135 Sriram Engineering College
136 SRR Engineering College
137 St. Anne’s College of Engineering and Technology
138 St. Joseph College Engineering
139 St. Peter’s College of Engineering and Technology
140 Surya Group of Institutions
141 Tagore Engineering College
142 Thangavelu Engineering College
143 Thirumalai Engineering College
144 Thiruvalluvar College of Engineering and Technology
145 TJ Institute of Technology
146 TJS Engineering College
147 TSM Jain College of Technology
148 Valliammai Engineering College
149 Varuvan Vadivelan Institute of Technology
150 Vel Tech
151 Vel Tech High Tech Dr. Rangarajan Dr. Sakunthala Engineering College
152 Vel Tech Multi Tech Dr. Rangarajan Dr. Sakunthala Engineering College
153 Velammal Engineering College
154 Velammal Institute of Technology
155 VI Institute of Technology


For a single phase capacitor start induction motor which of the following statements is valid ? (Gate-EE-2007)

For a single phase capacitor start induction motor which of the following statements is valid ? (Gate-EE-2007)


(A) The capacitor is used for power factor improvement
(B) The direction of rotation can be changed by reversing the main winding terminals
(C) The direction of rotation cannot be changed
(D) The direction of rotation can be changed by interchanging the supply terminals


Answer: B

The direction of rotation can be changed by either reversing the main winding terminals or starting winding terminals.

Friday, October 18, 2013

Statement: you can always give me a ring whenever you need Which one of the following is the best inference from the above statement ?

GATE-EE-2013
***********

Statement: you can always give me a ring whenever you need

Which one of the following is the best inference from the above statement ?

A. because i have a nice caller tune.

B. because i have a better telephone facility.

C. because a friend in need in a friend indeed.

D. because you need not to pay towards the telephone bills when you give me a ring.



Answer: C

Because a friend in need in a friend indeed.

The eddy current loss in an a-c electric motor is 100 watts at 50 Hz. Its loss at 100 Hz will be

The eddy current loss in an a-c electric motor is 100 watts at 50 Hz. Its loss at 100 Hz will be

(A) 25 watts 
(B) 59 watts
(C) 100 watts 
(D) 400 watts

Explanatory answer:

Eddy current losses is proportional to square of frequency 
( f^2)

In thise case frequency is doubled, so the New loss proportional to (2f)^2

New loss is proportional to 4f^2

Eddy current loss at 100 HZ is = 4 times greater
                                                     =  400 watts

Slip of the induction machine is 0.02 and the stator supply frequency is 50 Hz.What will be the frequency of the rotor induced emf?

Slip of the induction machine is 0.02 and the stator supply frequency is 50 Hz.What will be the frequency of the rotor induced emf?

(A) 10 Hz. 
(B) 50 Hz.
(C) 1 Hz.
(D) 2500 Hz.

Explanatory answer:

S= 0.02 ; f = 50 Hz
Therefore, frequency of rotor induced emf = s f
                                                                         = 0.02 x 50 = 1 Hz

Monday, October 14, 2013

The starting torque of a 1-phase induction motor is

The starting torque of a 1-phase induction motor is

(A) High.
(B) Moderate.
(C) Low.
(D) Zero

Explanatory answer:

The single-phase I.M motor starting torque is zero because of the pulsating single-phase magnetic flux. The starting of the motor requires the generation of a rotating magnetic flux similar to the rotating flux in a three-phase motor. 

Saturday, October 12, 2013

In a 3-phase synchronous motor

In a 3-phase synchronous motor

(A) the speed of stator MMF is always more than that of rotor MMF.
(B) the speed of stator MMF is always less than that of rotor MMF.
(C) the speed of stator MMF is synchronous speed while that of rotor MMF is zero.
(D) rotor and stator MMF are stationary with respect to each other.

Explanatory answer: D



Rotor & stator mmf are stationary w.r.t each other Because, Motor is magnetically locked into position with stator, the rotor poles are engaged with stator poles and both run synchronously in same direction.

Friday, October 11, 2013

An SCR is considered to be a semi-controlled device because (GATE-EE-2009)

An SCR is considered to be a semi-controlled device because (GATE-EE-2009)

(A) It can be turned OFF but not ON with a gate pulse.

(B) It conducts only during one half-cycle of an alternating current wave.

(C) It can be turned ON but not OFF with a gate pulse.

(D) It can be turned ON only during one half-cycle of an alternating voltage wave.

ANSWER: C

An SCR is considered to be a semi-controlled device because it can be turned ON but not OFF with a gate pulse.

Thursday, October 10, 2013

Match the items in List-I (To) with the items in the List-II (Use) and select the correct answer using the codes given below the lists. (GATE-EE-2009)

Match the items in List-I (To) with the items in the List-II (Use) and select the correct answer using the codes given below the lists. (GATE-EE-2009)

List-I
a. improve power factor
b. reduce the current ripples
c. increase the power flow in line
d. reduce the Ferranti effect

List-II
1. shunt reactor
2. shunt capacitor
3. series capacitor
4. series reactor

(A) a " 2, b " 3, c " 4, d " 1
(B) a " 2, b " 4, c " 3, d " 1
(C) a " 4, b " 3, c " 1, d " 2
(D) a " 4, b " 1, c " 3, d " 2


Answer: B

*.shunt capacitors are used to improve power factor
*.series reactors are used to reduce current ripples
*.series capacitors are used to increase power flow in line
*.shunt reactors re used to reduce the ferranti effect.


If the signal flow graph shown in the figure has M number of forward paths P number of individual loops,then

If the signal flow graph shown in the figure has M number of forward paths P number of individual loops,then

A. M=3 ,P=3
B. M=2 ,P=3
C. M=3 ,P=4
D. M=2 ,P=4




Explanatory answer:

Forward paths:
M1=G1G2G3G4
M2=G5G6G7G8

M=2

Individual loops:

P1=G2H2
P2=G3H3
P3=G6H6
P4=G7H7

P=4

A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of the machine as a motor will be

A dc shunt generator has a speed of 800 rpm when delivering 20 A to the load at the terminal voltage of 220V. If the same machine is run as a motor it takes a line current of 20A from 220V supply. The speed of the machine as a motor will be

(A) 800 rpm.
(B) more than 800 rpm.
(C) less than 800 rpm. 
(D) both higher or lower than 800 rpm.

Explanatory answer:

In generator

Ng= Eg (60A / FPZ) 

Eg = V + Ia Ra 

In motor

Nm= Eb (60A / FPZ) 

Eb = V - Ia Ra 

Eg > E b for same terminal voltage 

Therefore, Ng > N m

Less than 800 rpm.

Wednesday, October 9, 2013

The r.m.s. value of sinusoidal 100 V peak to peak is _________ volt.

The r.m.s. value of sinusoidal 100 V peak to peak is _________ volt.

(A) 100 √2
(B) 50√2

(C) 50
(D) 100

Explanatory answer:

For sinusoidal,
Rms value = peak value /  √2

Vpeak = Vp-p / 2 = 100/2 = 50

RMS value = 50/√2

If magnetic flux changes from 0.8 Wb to 0.3 Wb, then change in flux is______ Wb.

If magnetic flux changes from 0.8 Wb to 0.3 Wb, then change in flux is______ Wb.

(a) 1.1
(b) 0.5
(c) -0.5
(d) -1.1

Explanatory answer:

Change in flux= 0.3-0.8

change in flux =  -0.5

The no.of turns of a coil is 200 and if the current is 1 amps, then MMf is ...............

The no.of turns of a coil is 200 and if the current is 1 amps, then MMf  is ...............

A. 2000 AT
B. 200 AT
C.20 AT
D. 0.5 AT

Explanatory answer:

MMF= NI (AT)

MMF = 200*1 =200 AT

Tuesday, October 8, 2013

In DC generators, armature reaction is produced actually by

In DC generators, armature reaction is produced actually by
(A) Its field current.
(B) Armature conductors.
(C) Field pole winding. 
(D) Load current in armature.

Explanatory answer:

Ans: D

Because load current in armature gives rise to armature mmf which react with main field mmf.

A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number of poles of the motor are

A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number of poles of the motor are

(A) 4. 
(B) 6.
(C) 12. 
(D) 8.

Explanatory answer:

We know, N = (1-S)Ns

1440 = (1-S) Ns

Therefore, Ns = 1440/(1-S)

Ns = 120F/P = 120*50/P = 6000/P

always Ns will be closer to N. i.e. 1440

Let P=2, Ns=3000 rpm (not close to N)
Let P=4, Ns=1500 rpm (close to N)

Therefore, P=4 for N=1440

Monday, October 7, 2013

Match List I(unit) with list II (equivalent unit) and select the correct answers using the codes given below the list

Match List I(unit) with list II (equivalent unit) and select the correct answers using the codes given below the list

List I                                List II

A. Weber                       1. Ampere second per volt
B. Coulomb                   2. Volt-second
C. Farad                        3. Ampere-second
                                       4. Volt per second

      A    B   C
a.    1     2   3
b     2     3   1
c.    2     3   4
d.    3     1   4

Explanatory answer:

Weber is unit of flux =  Volt-second (By definition, a change in flux of one weber per second will induce in a circuit of one turn an electromotive force of one volt)


Coulomb is unit of charge  =  current*time = Ampere-second.

Farad is unit of capacitance  = charge/volt = Ampere second per volt.

Answer : 2 3 1

The equivalent current-source representation for a voltage-source with open circuit voltage 12 V and internal resistance 3 ohms is

The equivalent current-source representation for a voltage-source with open circuit voltage 12 V and internal resistance 3 ohms is 

(A) a current-source of strength 4A in shunt with a resistance of 6Ω. 

(B) a current –source of strength 4A in series with a resistance of 3Ω.

(C) a current-source of strength 4A in shunt with a resistance of 3 ohms. 

(D) a current-source of strength 4A in shunt with a resistance of 36 ohms. 

Explanatory answer :

A voltage source with series resistance can be transformed to a current source in parallel with a resistance

I = V/R = 12/3 = 4A and R = 3 (given)

Ans:  a current-source of strength 4A in shunt with a resistance of 3 ohms. 



Three capacitors of value 8µF , 16µF and 32µF are connected in series, the total capacitance will be

Three capacitors of value 8µF , 16µF and 32µF are connected in series, the total capacitance will be 

(A) 32/7 µF . 
(B) 7.32 µF . 
(C) 56 µF . 
(D) 32 µF . 

Explanatory answer:

For series connection of capacitors

C = C1C2C3 / ( C1C2+C2C3+C3C1)

C = 32/7 µF .

The input of an ac circuit having pf of 0.8 lag is 20 KVA. The power drawn by the circuit is .........KW

The input of an ac circuit having pf of 0.8 lag is 20 KVA. The power drawn by the circuit is .........KW

A. 12
B. 20
C. 16
D. 8

Explanatory answer:

 KVA= VI*10^3

Power  = VI * PF

Power drawn = KVA*PF = 20 * 0.8 = 16 KW

Wednesday, October 2, 2013

An SCR carrying a current of 5 A, the increase in load demands the anode current to rise to 50 A in 2 micro seconds. di/dt rating of SCR is 20 A per microsecond and maximum current rating is 60 A.Comment ,under this condition what happens to SCR.

An SCR carrying a current of 5 A, the increase in load demands the anode current to rise to 50 A in 2 micro seconds. di/dt rating of SCR is 20 A per microsecond and maximum current rating is 60 A.Comment ,under this condition what happens to SCR.

Explanatory answer: 


given, di/dt rating of SCR = 20 A/ us

but actual di/dt = 50 A per 2 microseconds =50/2 = 25 A/ us

Thus the actual di/dt is greater than the di/dt rating of SCR. This will lead to damage of SCR.

Match the pairs with respect to a thyristor

Match the pairs with respect to a thyristor














Answer:  

(i)-c
(ii)-d
(iii)-b
(iv)-a

The power electronic converter shown in figure has a single-pole-double-throw switch. The pole P of the switch is connected alternatively throws A and B. The converter shown is a

The power electronic converter shown in figure has a single-pole-double-throw switch. The pole P of the switch is connected alternatively throws A and B. The converter shown is a

A. step-down chopper (buck converter)
B. half-wave rectifier
C. step-up chopper (boost converter)
D. full wave rectifier.       (GATE-EE-2010)





Answer: It is a step-down chopper

A sine wave of voltage varies from zero to maximum of 200 V. How much is the voltage at the instant of 30 deg of the cycle ?

A sine wave of voltage varies from zero to maximum of 200 V. How much is the voltage at the instant of 30 deg of the cycle ?

A. 50 V
B. 82.8 V
C. 100 V
D. 173.2 V


Explanatory answer:

In general, Sine wave form is represented as Vm sin wt.

Vm = 200

at 30 deg,  200 sin (30) = 100 V

Ans: 100 V