Rearrange the following letters so as to form one word: NEW DOOR

Rearrange the following letters so as to form one word: 

NEW DOOR

Answer : ONE WORD

ohms law and its limitations

At constant temperature the current flowing through a conductor is directly proportional to voltage and inversly proportional to resistance.

A domestic mixer uses the __________ motor

A domestic mixer uses the __________ motor

(A) induction motor
(B) reluctance motor
(C) universal motor
(D) permanent magnet synchronous motor

Answer : universal motor

Basic ohms law

What is the difference between Electrical and Electronics ?

What is the difference between Electrical and Electronics ?

Electrical --- study of current flow in conductors.

Electronics ---study of current flow in semiconductors

A boy and a doctor was fishing.The boy is the doctor's son but the doctor is not the boy's father.who is the doctor?

A boy and a doctor was fishing.The boy is the doctor's son but the doctor is not the boy's father.who is the doctor?

Answer : Doctor is boy's mother.

If the no of valence electrons in an atom is less than four, then it is referred as .......................

If the no of valence electrons in an atom is less than four, then it is referred as .......................

a. semiconductor

b. conductor

c. insulator

Answer:

valence electron <  4 - conductor

valence electron > 4 - insulator

valence electron  = 4 - semiconductor 

What happens when a d.c motor is connected across an ac supply?

What happens when a d.c motor is connected across an ac supply?

• Since on ac supply, reactance will come in to play,the a.c supply will be offered impedance(not resistance) by the armature winding.consequently,with a.c supply,current will be much less.The motor will run but it would not carry the same load as it would on d.c. supply.
• There would be more sparking at the brushes
• Though motor armature is laminated as a rule, the field poles are not. consequently,eddy currents will cause the motor to heat up eventually burn on a.c. supply.

Why transformers are rated in KVA and motors are rated in KW ?

The power factor of transformer is dependent on load we only define Volt-ampere rating and does not include power factor  but in case of motors, power factor depend on construction and hence rating of motors is in KW and include power factor.

Why we can’t store AC in Batteries instead of DC?

Why we can’t store AC in Batteries instead of DC?

We cannot store AC in batteries because AC changes their polarity upto 50 (When frequency = 50 Hz) or 60 (When frequency = 60 Hz) times in a second. Therefore the battery terminals keep changing Positive (+ve) becomes Negative (-Ve) and vice versa, but the battery cannot change their terminals with the same speed so that’s why we can’t store AC in Batteries.
Also when we connect a battery with AC Supply, then It will charge during positive half cycle and discharge during negative half cycle because the Positive (+ve) half cycle cancel the negative (-Ve) half cycle, so the average voltage or current in a complete cycle is Zero. So there is no chance to store AC in the Batteries.

PARTS OF A SIM CARD

Which of the following equations is valid for a 3-phase 4-wire balanced star-connected load?

Which of the following equations is valid for a 3-phase 4-wire balanced star-connected load?

(a) IR + IY + IR = IN = O
(b) IN + IY – IB = IN
(c) IR – IY + IB = IN
(d) VB + VR + VY ⁄ Z =N


Answer: IR + IY + IR = IN = O

Balanced  circuit means the magnitude of each phase current is equal and neutral current is zero.

Does zero watts bulb consume no power ?

There is no bulb which consumes zero watt, it is not possible to light a bulb without drawing an current and consuming greater than zero watts .

Actually a zero watt bulb consumes about 12 to 15 watts, the inaccurate electric meters of the early days could not measure such a negligible amount of consumption as during those days,the energy meter had a rotating disc and when all other lights switched off,the disc would have minimum rotation,which would not record even a 10 watts consumption.This led to the term Zero-watt. 

The number of protons in silicon and germanium atom is

The number of protons in silicon and germanium atom is

a) 4 ,32
b) 16,32
c) 28,14
d) 14,32

Answer : 14,32

According to KVL, the algebriac sum of all IR drops and emf is in any closed loop of a network is always

According to KVL, the algebriac sum of all IR drops and emf is in any closed loop of a network is always

a. zero
b. postive
c. negative
d. determined by battery emfs.

Answer: The algebraic sum of voltage drops and emfs in a closed circuit is equal to zero.

What is hunting ?

What is hunting ?

• The oscillations of rotor due to sudden application or removal of load is called swinging or hunting.

• During hunting there are changes the current drawn by the motor which may cause problem to other appliances connected to the same line.Hence hunting is not desirable phenomenon from motor point of view and must be prevented.

What are the disadvantages of low power factor?

What are the disadvantages of low power factor?

Low power factor increases the current drawn from the supply to supply same power to the load.The high current due to low p.f has the following disadvantages:

• Large conductor size and  results in high cost
• More copper losses and poor efficiency.
• Large voltage drop,results in poor regulation.

Electrical quantities symbols and their units

EEE symposium-Ampere2k15-selvam college of technology

College                  : selvam college of technology

Event Name          : ampere2k15
Department          : EEE
Event Type           : Symposium
Email id                : ampere2k15@gmail.com

Event Description  :
Technical Events
1.Paper Presentation
2.Project Presentation
3.Circuit Debugging
4.Tech Marathon
5.Tech Quiz
Non Technical Events
1.Connection
2.Treasure Hunt

Event Address      : Selvam College of Technology

City               : Namakkal

Important Dates    :
Registration Start Date:10.02.2015
Paper submission Last  Date:13.02.2015
Event Date:20.02.2015

Contact Information:
Staff Co-ordinator:
          Er.V.Kumarakrishan AP/EEE
               96003 29100
          Er.G.Prabhakaran AP/EEE
               97507 22980

Student Co-ordinator
         Selvan.S.Krishnamani
           97880 08481
        Selvan.A.Aravindhan
           85081 60076 

REMOTE CONTROL FOR HOME APPLIANCES

connect this circuit to any of your home appliances (lamp, fan, radio, etc) to make the appliance turn on/off from a TV, VCD or DVD remote control. The circuit can be activated from up to 10 metres.

Logic gates and their truth tables

Electrical system of a car

Home appliances and their power consumption

The period of a sine wave is 1/50 seconds. its frequency is

The period of a sine wave is 1/50 seconds. its frequency is

A. 20 HZ
B. 30 HZ
C. 40 HZ
D. 50 HZ

Answer: 50 HZ

F = 1/T  = 50 HZ

A DC chopper remains ON for 36 μs. and OFF for 12 μs.What is its duty cycle ?

A DC chopper remains ON for 36 μs. and OFF for 12 μs.What is its duty cycle ?

A. 0.25

B. 0.75

C. 0.5

Answer: 0.75



Ton  = 36 μs.

Toff = 12 μs.

T = Ton + Toff = 48 μs.

Duty cycle = Ton / T

                  = 36 / 48
              
                  = 0.75

If the supply frequency increases, then skin effect is ...........

Answer: increases

The skin effect depends upon the following factors:

• Nature of material
• Diameter of wire - increases with the diameter of wire
• Frequency -    increases with the increases in frequency.
• Shape of wire - less for stranded conductor than the solid conductor.

Skin effect is negligible for Frequency < 50 Hz

Conductor diameter < 1 Cm

ANNA UNIVERSITY EXAMINATION RULES

Sl. No.	Nature of Malpractice	Maximum Punishment
1	Appeal by the candidate in the answer script o show mercy by way of awarding more than deserving marks.	Fine of Rs. 100/- per subject.
2	The candidate writing his/her name in the answer script.
3	The candidate writing his/her registration number/college name in places other than specified in the answer script.
4	Any special marking in the answer script by the candidate.
5	The candidate communicating with neighbouring candidate orally or non-verbally; the candidate causing suspicious movement of his/her body.
6	Irelevant writing by the candidate in the answer script.
7	The candidate marking on the question paper or writing answer on his/her question paper or making use of his/her question paper for rough work
8	The candidate posesing cell phones/programmable calculator(s)/any other electronic storage device(s) containing no incriminating materials	Fine of Rs. 200/- per subject.
9	The candidate faciltating the other candidate(s) to copy from his/her answer script	Invalidating the examination of the particular subject written by the candidate.
10	The candidate posesing any incriminating material(s) (whether used or not). For example:- Written or printed materials, bits of papers containing written information, writings on scale, calculator, handkerchief, dress, part of the body,Hall Ticket	Invalidating the examinations of the subject concerned and al the theory and the practical subjects of the current semester registered by the candidate. Further the candidate is not considered for revaluation of answer scripts of the arearrs-subjects. If the candidate has registered for arears-subjects only, invalidating the examinations of al the arears-subjects registered by the candidate.
11	The candidate posesing cell phone(s)/programmable calculator(s)/any other electronic storage device(s) and containing incriminating materials (whether used or not)
12	The candidate posesing the question paper of another candidate with aditonal writing on it.
13	The candidate pasing his/her question paper to another candidate with aditonal writing on it
14	The candidate pasing incriminating materials brought into the examination hal in any medium (hard/soft) to other candidate(s)
15	The candidate copying from neighbouring candidate.
16	Vulgar/ofensive writngs by the candidate in the answer script.	Invalidating the examinations of al the theory and practical subjects of the curent semester and al the arears- subjects registered by the candidate.
17	The candidate posesing the answer script of another candidate.
18	The candidate pasing his/her answers script o another candidate.
19	Apeal by the candidate in the answer script coupled with a promise of any form of consideration.
20	The candidate misbehaving in the examination hal.	Invalidating the examinations of al the theory and practical subjects of the curent semester and al the arear- subjects registered by the candidate; additional punishment: (i) if the candidate has not completed the programme, he/she is debared from continuing his/her studies for one year i.e., for two subsequent semesters. However the student is permited to apear for the examination in al the arears-subjects up to the last semester during the debared period. (i) if the candidate has completed the programme, he/she is prevented from writng the examinations of the arears- subjects for two subsequent semesters
21	Involved in any one or more of the malpractices of serial no. 10 to 19 for the second or subsequent imes
22	Cases of Impersonation	A) Handing over the impersonator to the police with a complaint o take apropriate action against the person involved in the impersonation by the Chief Supt. B) If a student of this University is found to impersonate a ‘bonafide student’, the impersonating student is debared from continuing his/her studies and writng the examinations permanently. He/she is not eligible for any further admision to any programme of the University. C) Debaring the ‘bonafide student’ for whom the impersonation was done from continuing his/her studies and writng the examinations permanently. He/she is not eligible for any further admision to any programme of the University

How does a bird does not get electric shock when they sit on electric wire?

How does a bird does not get electric shock when they sit on electric wire?


There is no voltage difference along a single wire the birds sitting on.since the birds are touching only one wire,the circuit is incomplete and the birds are safe.

To get shocked,electricity has to travel through its body;this requires two conductors.

Large birds can be shocked because they can make contact with two conductors,usually at a metal power pole.

What is the difference between unilateral and bilateral elements?

What is the difference between unilateral and bilateral elements?

Bilateral element: Voltage-current relation is the same for current flowing in either direction.

example: resistor,inductor and capacitor.

Unilateral element: different relations between Voltage and current for the two possible directions of current.

example: Vacuum tubes, silicon diodes, metal rectifiers ect.

Anna university BE/ B.TECH FINAL YEAR Project report format

Anna university BE/ B.TECH  FINAL YEAR  Project report format


Final year students of the Anna university should follow the following format to do the project report works.

To download: CLICK HERE

Which word, if pronounced right, is wrong, but if pronounced wrong is right?

Answer:  the word 'Wrong'

In a SCRs

In a SCRs

(a) Both Latching current and holding current are associated with turn-off process
(b) Latching current is associated with turn-off process and holding current with turn on process
(c) Holding current is associated with turn-off process and Latching current with turn-on process
(d) Both Latching current and holding current are associated with turn on process


Answer: (c) Holding current is associated with turn-off process and Latching current with turn-on process

civil service interview question

A fresher was sitting in an interview. The interviewer said, "This is the last question of your interview. Tell me the accurate position of the center of this table where your resume is kept."

How can he answer this question? What will you have answered to such a question?

answer:

Put your finger confidently at a supposedly center point of the table and tell him that this is the exact center point.

The interviewer will ask, “How do you know this is the exact center?"

You can revert back that your last question was the previous question and thus you are not liable to answer further.

This is just a matter of being quick witted. The cleverer you are, the better the impression will be.

The electric motor used in portable drills is.............

The electric motor used in portable drills is.............

a.capacitor-run motor
b.hysteresis motor
c. universal motor
d. repulsion motor

Answer: universal motor

A and B are young ones of C. If C is the father of A but B is not the son of C. How are B and C related

A and B are young ones of C. If C is the father of A but B is not the son of C. How are B and C related

a.  Niece and Uncle
b. Daughter and Father
c. Niece and Uncle
d. Daughter and Mother

Answer: b

C has two children A and B, if A is his son, B must be his daughter. 

What is the difference between active and passive elements ?

What is the difference between active and passive elements ?

An active element is one, which is capable of generating the energy on its own. Examples,transistor,current source , FET, ect.

A passive element is one, which is incapable of generating energy on its own. But it is capable of storing and dissipating energy.It always need some external source of power.Examples, resistor, capacitor, inductor, ect.

The quantity of charge that will be transferred by a current flow of 10 A over 1 hour period is

The quantity of charge that will be transferred by a current flow of 10 A over 1 hour period is

a. 10 C
b. 36000 C
c. 2400 C
d. 160 C

Answer:

t= 1 hr = 3600 sec

Q=I*t  = 10*1*3600 = 36000 coulombs

Why power factor is not more than unity?

• Power factor is the cosine angle between voltage and current.The magnitute of cosine is never greater than one.

• The power factor is equal to watts/ Volt-Amps.Watts can never exceed Volt-amps

                                          

A lamp draws 0.5 A at 230 V. If the voltage is reduced to 115 V, will the current be halved ?

A  lamp draws 0.5 A at 230 V. If the voltage is reduced to 115 V, will the current be halved ?

No.because ohms law is true for constantant temperature.If the voltage is reduced from 230 to 115 volt,results in decrease in resistance. Consequently ohms law cannot be applied.

Why field rheostat is kept in minimum position while armature rheostat is at maximum position ?

Why field rheostat is kept in minimum position while armature rheostat is at maximum position ?

At the time of starting of motor, the armature resistance is kept at maximum position to control and reduce the high starting current and field rheostat at minimum position to ensure that speed does not go beyond rated value and to have high starting torque.

A 230 V supply is connected across series combination of two bulbs of 60W and 100W respectively.which bulb will glow bright and why ?

A 230 V supply is connected across series combination of two bulbs of 60W and 100W respectively.which bulb will glow bright and why ?

we know in series connection the current is same and voltage is different which depends on resistance of the individual elements connected.

P=V^2/ R, to maintain this relationship the resistance of 60W bulb is greater and voltage across 60 W bulb is more(V=IR).so 60W bulb will glow brighter than 100W bulb.

What is the difference between active and passive elements ?

An active element is one, which is capable of generating the energy on its own. Examples,transistor,current source , FET, ect.

A passive element is one, which is incapable of generating energy on its own. But it is capable of storing and dissipating energy.It always need some external source of power.Examples, resistor, capacitor, inductor, ect.

Permanent magnet moving coil instrument can be used for ..........

Permanent magnet moving coil instrument can be used for ..........

a. ac work only
b. dc work only
c. both dc and ac work
d. none of the above.

Answer: dc work only

In a.c, the deflecting torque of the instrument reverses if the current reverses and hence the pointer cannot follow the rapid  reversals and the deflection corresponds to  a mean torque value of zero.so these instruments cannot be used for a.c.

In a.c system, we generate sine waveform because....................

In a.c system, we generate sine waveform because....................

a. it can be  easily drawn.
b. it produces least distrubance in electrical circuits.
c.it is nature standard.
d.other waves cannot be produced easily.

Answer:it produces least distrubance in electrical circuits.

Why is a shunt motor called constant speed motor ?

Why is a shunt motor called constant speed motor ?

In dc shunt motor flux produced by field winding is proportional to field current Ish. Here the input voltage is constant so field current and flux is also constant.Therefore, dc shunt motor is also called a constant flux or constant speed motor.

What do you mean by balanced load and un balanced load ?

• A load is said to be balanced load, if power factors and phase currents in the 3-phases are equal.

• A load is said to be ubalanced load, if power factors and phase currents in the 3-phases are unequal.

What is the relation between electrical and mechanical degree?

The relationship between mechanical and electrical degrees is

1 degree mechanical = (P/2) electrical degrees

Where P = no. of poles

i.e. for 1 deg of mechanical revolution of conductor inside a magnetic field produces (P/2) degree electrical output.

How the direction of rotation of a dc motor can be reversed ?

The direction of a dc motor can be reversed either by reversing current through field winding or armature winding . Usually current through armature will be reversed.

Define power factor.

• The power factor is the cosine of the angle between voltage and current.

• Power factor = resistance / impedance

                       ( or)

• Power factor = real power / apparent power

Define analog signal & digital signal.

• The amplitude of the signal varies continously with time.This signal is called analog signal.

• A signal defined at discrete instants of time is called digital signal.

Mention the applications of PN diode ?

• As switches

• As rectifiers

• Power supplies

• Clippers & Clampers

• Digital systems

• Communication systems