BATTERY LIFE AND SIGNAL STRENGTH

Lower signal quality tends to use more battery. On standby if you lose signal, the phone will use more power trying to re-acquire a signal than it would with a constant signal. Also with a weaker signal the phone may have to retransmit more and therefore use more power that way.

Cell phones are limited to 1 watt maximum transmission power; but most of the time they use significantly less. If a phone is in a marginal area, it can maintain a signal by increasing the transmission power -- but it comes at the cost of a huge hit to battery life.


R.Isaac Sajan
A.P/CSE
Ponjesly College of Engineering

GOOGLE GLASS

Google Glass is a wearable computer with an optical head-mounted display (OHMD) that is being developed by Google in the Project Glass research and development project, with a mission of producing a mass-market ubiquitous computer. Google Glass displays information in a smartphone-like hands-free format, that can communicate with the Internet via natural language voice commands. 

While the frames do not currently have lenses fitted to them, Google is considering partnerships with sunglass retailers such as Ray-Ban or Warby Parker, and may also open retail stores to allow customers to try on the device. The Explorer Edition cannot be used by people who wear prescription glasses, but Google has confirmed that Glass will eventually work with frames and lenses that match the wearer's prescription; the glasses will be modular and therefore possibly attachable to normal prescription glasses. It is necessary to remove a small screw in order to move the Google Glass from one frame to another.

Glass is being developed by Google X, which has worked on other futuristic technologies such as driverless cars. The project was announced on Google+ by Project Glass lead Babak Parviz, an electrical engineer who has also worked on putting displays into contact lenses; Steve Lee, a product manager and "geolocation specialist"; and Sebastian Thrun, who developed Udacity as well as worked on the autonomous car project. Google has patented the design of Project Glass. Thad Starner, an augmented reality expert, is a technical lead/manager on the project. 

R.Isaac Sajan

A.P/CSE

Ponjesly College of Engineering

MECHCARNIC 2K14

Noorul Islam University 

Department of Mechanical Engineering 

“MECHCARNIC 2K14” 

We the Department of Mechanical Engineering, Noorul Islam University glad to inform you that our upcoming symposium ‘MECHCARNIC 2K14’, which is scheduled on 20th & 21st Feb 2014.

The theme of the symposium: “SECURING TOMORROW’S ENERGY TODAY”.

Various esteemed institution such as Indian Space Research Organization (ISRO), Indian Rare Earth ltd-Manavalakuruchi, NPCIL, Kudankulam and Kalpakkam(IGCAR) are exhibiting their models on this upcoming program. And Agriculture exhibition, Auto expo which has a wide range of automobile collection from Vintage model to the next generation models, project expo of college and school students from various institutions. We are also conducting the following competitions.

(1)For Engineering and Polytechnic Students:

Project expo

CAD Modeling

Water Rocketry

Technical Paper Presentation

Short Film Fest


(2) For School Students:

Project Expo

Elocution competition

Essay writing

Drawing competition

Poetry writing

Youth Parliaments

Photography

Debate



Total prize worth “Rupees Two lakhs”.

We are requesting teachers to encourage the students to participate in various events and allow your students to visit the various EXPO.  Students can interact with the scientists from departments like ISRO, Kudankulam. .and kalpakkam neuclear power plant, etc. We also provide facilities to visit hangers, aircrafts, and ships. And to know about their workings.



Contact Details


Dr.R.Rajesh,Professor & Head, Dept. of Mechanical Engineering, Noorul Islam University
Prof.K.Vinoth Babu: 9894030936
Prof.JamesDhinakar: 9894824253

Electronics Quiz

POWER ELECTRONICS

[1] When a line commutated converter operates in the inverter mode
(a) It draws both real and reactive power from the AC supply
(b) It delivers both real and reactive power to the AC supply
(c) It delivers real power to the AC supply
(d) It draws reactive power from the AC supply
Answer: C
[2] A chopper operating at a fixed frequency is feeding an RL load. As the duty ratio of the chopper is increased from 25% to 75%, the ripple in the load current is
(a) Remains constant
(b) Decreases, reaches a minimum at 50% duty ratio and then increases
(c) Increases, reaches a maximum at 50% duty ratio and then decreases
(d) Keeps on increasing as the duty ratio is increased
Answer: A
[3] To turn off a SCR, the reverse bias should be applied for a period ....... the turn-off time of the SCR
(a) Equal to
(b) Longer than
(c) Less than
(d) Irrespective of
Answer: B
[4] In class A and class B commutation the resonating circuit has to be
(a) Over damped
(b) Critically damped
(c) Under damped
(d) Negatively damped
Answer: C
[5] In phase controlled rectification power factor (PF)
(a) Remains unaffected
(b) Improves with increase of firing angle α
(c) Deteriorates with increase of α
(d) Is unrelated to α
Answer: C
[6] Comparing with the full wave rectifier using two diodes, the four diode bridge rectifier has the dominant advantage of
(a) Higher current carrying
(b) Lower peak inverse voltage requirement
(c) Lower ripple factor
(d) Higher efficiency
Answer: B
[7] A SCR is rated at 75A peak, 20A average. The greatest possible delay in the trigger angle if the dc is at rated value is
(a) 47.5°
(b) 30° to 45°
(c) 74.5°
(d) 137°
Answer: B
[8] The applied sine voltage to a SCR is VM=200V and R=10Ohm. If the gate trigger lags the ac supply by 120°, the average load current is
(a) 15/π A
(b) 5/π A
(c) -5/π A
(d) -15/π A
Answer: A
[9] A sine voltage of 200Vrms, 50Hz is applied to an SCR through 100ohm resistor. The firing angle is 60°. Consider no voltage drop. The output voltage in rms is
(a) 89.7 V
(b) 126.7 V
(c) 166.7 V
(d) 200√2 V
Answer: B
[10] A 100VDC is applied to the inductive load through a SCR. The SCR's specified latching current is 100mA. The minimum required width of gating pulse to turn on the SCR is
(a) 100μS
(b) 100S
(c) 1mS
(d) 50μS
Answer: A
[11] A cycloconverter is a
(a) Frequency changer from higher to lower frequency with one-state conversion
(b) Frequency changer from higher to lower frequency with two-stage conversion
(c) Frequency changer from lower to higher frequency with one-stage conversion
(d) Either a or c
Answer: D
[12] The cycloconverter require natural or forced commutation as under
(a) Natural commutationin bothstep-up and step down cycloconverter
(b) Forced commutation in both step-up and step-down cycloconverter
(c) Forced commutation in step-up cycloconverter
(d) Forced commutation in step-down cycloconverter
Answer: C
[13] In synchronized UJT triggering of an SCR, voltage VC across capacitor reaches UJT threshold thrice in each half cycle so that there are three firing pulses during each half cycle. The firing angle of the SCR can be controlled
(a) Once in each half cycle
(b) Thrice in each half cycle
(c) Twice in each half cycle
(d) Four times in each half cycle
(e) None of the above
Answer: A
[14] In a GTO, anode current begins to fall when gate current
(a) Is negative peak at time t=0
(b) Is negative peak at t = storage period tS
(c) Just begins to become negative at t = 0
(d) Is negative peak at t = (tS + fall time)
Answer: B
[15] The SCR can be turned on by
(a) Applying anode voltage at a sufficiently fast rate
(b) Applying sufficiently large
(c) Increasing the temperature of SCR to a sufficiently large value
(d) Applying sufficiently large gate current
OPTIONS:
1) A, B
2) C, D
3) B, C
4) A, B, C, D
5) None of the above options
Answer: 4

ICRAMID-2014 at Ponjesly College of Engineering

The International conference on "Recent Advances in Mechanical Engineering and Interdisciplinary Developments"(ICRAMID-2014) will be held at Ponjesly College of Engineering , India, during 7th and 8th march 2014. This conference will provide an opportunity for practitioners, researchers, technologists and business leaders to exchange their ideas about the recent advances in Mechanical Engineering and interdisciplinary developments. Many experts from the field of mechanical Engineering are the members of advisory & technical committees, and provide their rich experience in organizing this conference. Technologists, Scientists, Professionals and Research scholars are invited to present their original work and experiences as technical paper in the conference

Click here for the website link : www.icramid2014.org

 

Test your Programming skills

PONJESLY COLLEGE OF ENGINEERING

TEST YOUR C- SKILS

1. What will be the output of the following program?

#include<stdio.h>

int x= 40 // Global Declaration

void main()

{

int x=20; // Local Declaration

printf(“\n%d”, x);

}

2. What will be the output of the following program?

#include<stdio.h>

void main()

{

int x= 40 //Local Variable

{

int x=20; // Most Local variable

printf(“\n%d”, x);

}

printf(“\n%d”, x);

}

Answers:

1. 20, Whenever there is a conflict between a local variable and a global variable, the local variable will get the priority.
2. 20 40, Now both are local variables. In this case the most local variable will get the priority.

By,

IT Department,PJCE

LOGICAL MATHS

INSERT THE MISSING NUMBER

1. 8 15 34
12 6 18
40 5 ?


a) 45 b) 30 c) 60 d) 35


2. 175 (576) 463
192 ( ) 357


a) 288 b) 82 c) 330 d) 357


3. 514, 258, 130, 66?


a) 34 b) 33 c) 36 d) 38




4. 15 7 10 12
25 5 7 ?
16 8 4 20


a) 27 b) 13 c) 23 d) 47


5. 8,17,33,67,133, ?


a) 264 b) 265 c) 266 d) 267









ANSWERS:

1. b
   

(15*2) + (8/2) =34, (6*2) + (12/2) =18 Hence (5*2) + (40/2)=30

2. c
   

See the difference between the numbers outside the brackets and multiply the result by 2.

3. a
   

514/2 +1=258, 258/2 +1=130, 130/2 +1=66, 66/2 +1=34

4. c
   

See the horizontal rows. 15+7-10= 12. Therefore 25+5-7=23

5. d
   

8*2+1=17, 17*2-1=33, 33*2+1=67, 67*2-1=133,133*2+1=267.
By
JEYA PRABHA.R

IV IT  

Tech Quiz !!!

PONJESLY COLLEGE OF ENGINEERING

DEPARTMENT OF ECE

TECHNICAL QUIZ

Dear engineers, check how strong you are in your basics of electronics. The questions are given in a quiz form. So check how strong you are.

1. In a transistor when base-width decreases with increasing collector to base voltage, this phenomenon is called
   
   1. Early Effect
   2. Thermal Runaway
      
   3. Tunneling
      
   4. Pinch-off
      
2. The bridge used for measurement of inductance is
   
   1. Wheatstone Bridge
      
   2. Kelvin Double Bridge
      
   3. Anderson Bridge
      
   4. Schering Bridge
      
3. The type of transmission used for sound in TV transmission is
   
   1. AM
      
   2. FM
      
   3. PCM
      
   4. PWM
      
4. The type of transmission used for television in India is
   
   1. DAB SC
      
   2. SSB
      
   3. VSB
      
   4. SSB-SC
      
5. The memory unit using only gates is
   
   1. ROM
      
   2. RAM
      
   3. Core
      
   4. Disk
      
6. Most commonly used materials as photo cathode for the photoelectric emission are
   
   1. Barium and Calcium
      
   2. Cesium and Ribidium
      
   3. Arsenic and Boron
      
   4. Thorium and Tungsten
      
7. In every practical oscillator the loop gain is
   
   1. Slightly larger than unity
      
   2. Slightly larger than ten
      
   3. Infinity
      
   4. Zero
      
8. A series capacitance used in a filter circuit represents
   
   1. Low-Pass
      
   2. Band-Pass
      
   3. High-Pass
   4. None
      
9. Clipper circuits are used to obtain any one of the following waveforms
   
   1. Sharper
      
   2. Rectified
      
   3. Fast Rising
      
   4. Smaller Amplitude
      
10. Plasma is
    
    1. A medium dominated by helium
       
    2. A solid dielectric material
       
    3. A gaseous medium
       
    4. A ray of electrons
11. Which is most commonly used transmission-line with television system?
    
    1. Twin-lead
       
    2. Open-wire with ceramic supports
       
    3. Coaxial Cable
       
    4. None of these
       
12. Video signals have a frequency range that is spread over approximately
    
    1. 9 Octaves
       
    2. 18 Octaves
       
    3. 4 Octaves
       
    4. None of these
       
13. Where is brightness control located in a TV?
    
    1. Audio Section
       
    2. Video Section
       
    3. Grid-cathode circuit of picture tube
       
    4. None of these
       
14. LED is
    
    1. A PN junction which emits light when current passes in the forward direction
       
    2. A gaseous discharge glow devices
       
    3. Photo cell device which emits light
    4. None of the above
       
15. The oscillator that has the best frequency stability is
    
1. Crystal Oscillator
   
2. Hartley Oscillator
   
3. Colpitt's
   
4. Tuned Collector Oscillator
   

Answers: 1) a 2) c 3)b 4)c 5)b 6)c 7) a 8)c 9) d 10)c 11) c 12) c 13) a 14) a 15) a