Delta connection

Star-Delta connection

GK Quizzes

General Knowledge GK Paper For BANK 2011 -2012 / SAMVIDA SSC CLERK DATA ENTRY OPERATOR / LDC / POLICE CONSTABLE SAMPLE PAPER Top of Form

Bottom of Form

1. Brickfielder, Khamsin and Harmattan are the examples of…
a. hot winds
b. cold winds
c. trade winds
d. planetary winds
2. The world-famous Khajuraho temples were built by the rulers of…
a. Gupta dynasty
b. Chandela dynasty
c. Pallava dynasty
d. Chola dynasty
3. The world’s first Earth Summit took place in the year…
a. 1988
b. 1990
c. 1992
d. 1994
4. Dilli Chalo is the famous call that you would associate with …
a. Lal Bahadur Shastri
b. Acharya Binoba Bhave
c. Subhash Chandra Bose
d. Bhagat Singh
5. World Consumer Day is celebrated throughout the world on …
a. February 22
b. March 15
c. April 8
d. May 11
6. The freezing point of water is …
a. Zero K
b. 273.15 K
c. 313.16 K
d. 474.15 K

7. Which country’s constitution is the source of the Fundamental Rights of the Constitution of India?
a. The UK
b. Ireland
c. The US
d. Former Soviet Union
8. According to the latest census 2001, this state is the least populous state of India. Can you identify the name of the state from the given options?
a. Goa
b. Arunachal Pradesh
c. Sikkim
d. Manipur
9. Which of the following is the smallest country of the world?
a. Tuvalu
b. Vatican
c. Nauru
d. Kuwait
10. The layer nearest to the earth’s atmosphere is …
a. Mesosphere
b. Ionosphere
c. Troposphere
d. Stratosphere
11. Zulu is the name of the tribe that belongs to …
a. Australia
b. New Zealand
c. South Africa
d. Indonesia
12. A normal human being has … chromosomes in all.
a. 42
b. 44
c. 46
d. 48
13. Utigard, Ribbon and Roraima are the names of the famous…
a. Volcanos
b. Waterfalls
c. Mountains
d. Lakes
14. Ain-e-Akbari, that gives the account of Akbar’s reign, was written by…
a. Amir Khusro
b. Firdausi
c. Abul Fazal
d. Badauni
15. This Indian state is the largest producer of rubber. Identify it from the given options.
a. Karnataka
b. Kerala
c. Tamil Nadu
d. Andhra Pradesh
16. ‘Bogey’ and ‘Fore’ are the terms that you would associate with
a. Chess
b. Snooker
c. Golf
d. Billiards
17. Khadar and Bhangar are the two types of…
a. Black Soil
b. Alluvial Soil
c. Red Soil
d. Laterite Soil
18. The first person to walk in Space was …
a. Neil Armstrong
b. Yuri Gagarin
c. AA Leonov
d. Edwin Eldrin
19. Where would you find Buland Jarwaza - the highest gateway in India?
a. Bihar
b. Punjab
c. Uttar Pradesh
d. Madhya Pradesh
20. ‘Gambit’ is a term that you would associate with…
a. Hockey
b. Cricket
c. Chess
d. Football
21. Indica is the name of a famous work of …
a. AO Hume
b. Megasthenese
c. Thomas Roe
d. None of these
22. She is the first lady President of the world. Can you identify her from the given options?
a. Srimavo Bandaranaike
b. Barbara C. Harris
c. Maria Estella Peron
d. Junko Taibei
23. The main source of Indian philosophy is contained within the …
a. Vedas
b. Brahmanas
c. Puranas
d. Upanishads
24. Discovery of India is a famous book written by …
a. Mahatma Gandhi
b. Pt. Jawaharlal Nehru
c. Maulana Abdul Kalam Azad
d. Dr. Rajendra Prasad
25. The largest Hindu complex outside India, Angkor Vat in Cambodia, is dedicated to …
a. Lord Shiva
b. Lord Brahma
c. Lord Vishnu
d. Lord Rama

ANSWERS

1. a. Hot winds
2. b. Chandela dynasty
3. c. 1992
4. c. Subhash Chandra Bose
5. b. March 15
6. b. 273.15K
7. c. The US
8. c. Sikkim
9. b. Vatican
10. c. Troposphere
11. c. South Africa
12. c. 46
13. b. waterfalls
14. c. Abul Fazal
15. b. Kerala
16. c. Golf
17. b. Alluvial Soil
18. c. AA leonov
19. c. Uttar Pradesh
20. c. Chess
21. b. Megasthenese
22. c. Maria estate Peron
23. d. Upanishads
24. b. Pt. Jawaharlal Nehru
25. c. Lord Vishnu

What is Electrical Engineering????

What is Electrical Engineering?

Electrical engineers have made remarkable contributions to our world. They helped invent the computer, DSL, cellular phones, microchips, and solar panels–to name just a few examples. DVD players, cellular phones, radio, television, computers, airplanes, space vehicles, cars, motorcycles, home appliances, life-saving medical equipment, computer games, and Martian battles fought with joysticks represent a mere sampling of the now familiar facets of life made possible with the input of electrical engineers. Ten key industry sectors employ electrical engineers, computer engineers, and computer scientists:

What is Computer Engineering?

What is Computer Engineering?

Computer engineers analyze and evaluate computer systems, both hardware and software. They might work on systems such as a flexible manufacturing system or a "smart" device or instrument. Computer engineers often find themselves focusing on problems or challenges that result in new "state-of-the-art" products, which integrate computer capabilities. They work on the design, planning, development, testing, and even the supervision of manufacturing of computer hardware–including everything from chips to device controllers.
They work on the interface between different pieces of hardware and strive to provide new capabilities to existing and new systems or products. The work of a computer engineer is grounded in hardware–from circuits to architecture–but also focuses on operating systems and software. Computer engineers must understand logic design, microprocessor system design, computer architecture, computer interfacing, and continually focus on system requirements and design. It is primarily software engineers who focus on creating the software systems used by individuals and businesses, but computer engineers may also design and develop some software applications.

What is Engineering ???

What is Engineering?

Engineering is the practical application of science and math to solve problems, and it is everywhere in the world around you. From the start to the end of each day, engineering technologies improve the ways that we communicate, work, travel, stay healthy, and entertain ourselves.

Engineers are problem-solvers who want to make things work more efficiently and quickly and less expensively. From computer chips and satellites to medical devices and renewable energy technologies, engineering makes our modern life possible. In particular, electrical engineers and computer engineers have a wide range of study options and career paths that let them design, build, and manage those ideas into reality.

DIFFERENT B/W CAPACITIVE AND INDUCTIVE LOAD

In a capacitive load current lead voltage by 90 degree and in Inductive load voltage lead current by 90 degree. Combined together and driven by a PULSE, you can have resonant circuit.

       To improve power consumption , you can reduce the power factor by using capacitance in a inductive load and vice-versa. SO it depend on load.

In power system to be efficient you need to stay b/w 1(unity) and 0.95 leading this gives a higher efficiency and less reactive power Kvar

It is balance to correct load , to reduce lag add some resistive load. 

AC/DC Formulas

E = Voltage / I = Amps /W = Watts / PF = Power Factor / Eff = Efficiency / HP = Horsepower

AC/DC Formulas
To Find	Direct Current	AC / 1phase  115v or 120v	AC / 1phase 208,230, or 240v	AC 3 phase All Voltages
Amps when Horsepower is Known	HP x 746 E x Eff	HP x 746 E x Eff X PF	HP x 746 E x Eff x PF	HP x 746 1.73 x E x Eff x PF
Amps when Kilowatts is known	kW x 1000 E	kW x 1000 E x PF	kW x 1000 E x PF	kW x 1000 1.73 x E x PF
Amps when kVA is known		kVA x 1000 E	kVA x 1000 E	kVA x 1000 1.73 x E
Kilowatts	I x E 1000	I x E x PF 1000	I x E x PF 1000	I x E x 1.73 PF 1000
Kilovolt-Amps		I x E 1000	I x E 1000	I x E x 1.73 1000
Horsepower (output)	I x E x Eff 746	I x E x Eff x PF 746	I x E x Eff x PF 746	I x E x Eff x 1.73 x PF 746

Three Phase Values

For 208 volts x 1.732, use 360 For 230 volts x 1.732, use 398 For 240 volts x 1.732, use 416 For 440 volts x 1.732, use 762 For 460 volts x 1.732, use 797 For 480 Volts x 1.732, use 831

E = Voltage / I = Amps /W = Watts / PF = Power Factor / Eff = Efficiency / HP = Horsepower

AC Efficiency and Power Factor Formulas
To Find	Single Phase	Three Phase
Efficiency	746 x HP E x I x PF	746 x HP E x I x PF x 1.732
Power Factor	Input Watts V x A	Input Watts E x I x 1.732

Power - DC Circuits

Watts = E xI

Amps = W / E

Ohm's Law / Power Formulas
	P = watts I = amps R = ohms E = Volts

Voltage Drop Formulas
Single Phase (2 or 3 wire)	VD =	2 x K x I x L CM	K = ohms per mil foot   (Copper = 12.9 at 75°) (Alum = 21.2 at 75°) Note: K value changes with temperature. See Code chapter 9, Table 8 L = Length of conductor in feet I  = Current in conductor (amperes) CM = Circular mil area of conductor
	CM=	2K x L x I VD
Three Phase	VD=	1.73 x K x I x L CM
	CM=	1.73 x K x L x I VD

Calculating Motor Speed:

A squirrel cage induction motor is a constant speed device. It cannot operate for any length of time at speeds below those shown on the nameplate without danger of burning out.

To Calculate the speed of a induction motor, apply this formula:

Srpm = 120 x F
            P

Srpm = synchronous revolutions per minute.
120   = constant
F       = supply frequency (in cycles/sec)
P       = number of motor winding poles

Example: What is the synchronous of a motor having 4 poles connected to a 60 hz power supply?

Srpm = 120 x F
            P
Srpm = 120 x 60
            4
Srpm = 7200
             4
Srpm = 1800 rpm

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Calculating Braking Torque:

Full-load motor torque is calculated to determine the required braking torque of a motor.
To Determine braking torque of a motor, apply this formula:

T = 5252 x HP
    rpm

T      = full-load motor torque (in lb-ft)
5252 = constant (33,000 divided by 3.14 x 2 = 5252)
HP    = motor horsepower
rpm = speed of motor shaft

Example: What is the braking torque of a 60 HP, 240V motor rotating at 1725 rpm?

T = 5252 x HP
    rpm
T = 5252 x 60
     1725
T = 315,120
     1725
T = 182.7 lb-ft

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Calculating Work:

Work is applying a force over a distance. Force is any cause that changes the position, motion, direction, or shape of an object. Work is done when a force overcomes a resistance. Resistance is any force that tends to hinder the movement of an object.If an applied force does not cause motion the no work is produced.

To calculate the amount of work produced, apply this formula:

W = F x D

W = work (in lb-ft)
F  = force (in lb)
D  = distance (in ft)

Example: How much work is required to carry a 25 lb bag of groceries vertically from street level to the 4th floor of a building 30' above street level?

W = F x D
W = 25 x 30
W = 750 -lb

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Calculating Torque:

Torque is the force that produces rotation. It causes an object to rotate. Torque consist of a force acting on distance. Torque, like work, is measured is pound-feet (lb-ft). However, torque, unlike work, may exist even though no movement occurs.

To calculate torque, apply this formula:

T = F x D

T = torque (in lb-ft)
F = force (in lb)
D = distance (in ft)

Example: What is the torque produced by a 60 lb force pushing on a 3' lever arm?

T = F x D
T = 60 x 3
T = 180 lb ft

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Calculating Full-load Torque:

Full-load torque is the torque to produce the rated power at full speed of the motor. The amount of torque a motor produces at rated power and full speed can be found by using a horsepower-to-torque conversion chart. When using the conversion chart, place a straight edge along the two known quantities and read the unknown quantity on the third line.

To calculate motor full-load torque, apply this formula:

T = HP x 5252
    rpm

T = torque (in lb-ft)
HP = horsepower
5252 = constant
rpm = revolutions per minute

Example: What is the FLT (Full-load torque) of a 30HP motor operating at 1725 rpm?

T = HP x 5252
    rpm
T = 30 x 5252
     1725
T = 157,560
     1725
T = 91.34 lb-ft

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Calculating Horsepower:

Electrical power is rated in horsepower or watts. A horsepower is a unit of power equal to 746 watts or 33,0000 lb-ft per minute (550 lb-ft per second). A watt is a unit of measure equal to the power produced by a current of 1 amp across the potential difference of 1 volt. It is 1/746 of 1 horsepower. The watt is the base unit of electrical power. Motor power is rated in horsepower and watts.
Horsepower is used to measure the energy produced by an electric motor while doing work.

To calculate the horsepower of a motor when current and efficiency, and voltage are known, apply this formula:

HP = V x I x Eff
        746

HP = horsepower
V    = voltage
I     = curent (amps)
Eff. = efficiency

Example: What is the horsepower of a 230v motor pulling 4 amps and having 82% efficiency?

HP = V x I x Eff
        746
HP = 230 x 4 x .82
        746
HP = 754.4
        746
HP = 1 Hp

Eff = efficiency / HP = horsepower / V = volts / A = amps / PF = power factor

Horsepower Formulas
To Find	Use Formula	Example
		Given	Find	Solution
HP	HP = I X E X Eff.        746	240V, 20A, 85% Eff.	HP	HP = 240V x 20A x 85%        746 HP=5.5
I	I = HP x 746      E X Eff x PF	10HP, 240V, 90% Eff., 88% PF	I	I = 10HP x 746       240V x 90% x 88% I = 39 A

To calculate the horsepower of a motor when the speed and torque are known, apply this formula:

HP = rpm x T(torque)
         5252(constant)

Example: What is the horsepower of a 1725 rpm motor with a FLT 3.1 lb-ft?

HP = rpm x T
         5252
HP = 1725 x 3.1
         5252
HP = 5347.5
         5252
HP = 1 hp

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Calculating Synchronous Speed:

AC motors are considered constant speed motors. This is because the synchronous speed of an induction motor is based on the supply frequency and the number of poles in the motor winding. Motor are designed for 60 hz use have synchronous speeds of 3600, 1800, 1200, 900, 720, 600, 514, and 450 rpm.

To calculate synchronous speed of an induction motor, apply this formula:

rpmsyn = 120 x f
              Np

rpmsyn = synchronous speed (in rpm)
f           = supply frequency in (cycles/sec)
Np       =  number of motor poles

Example: What is the synchronous speed of a four pole motor operating at 50 hz.?

rpmsyn = 120 x f
              Np
rpmsyn = 120 x 50
              4
rpmsyn = 6000
              4
rpmsyn = 1500 rpm

Transfor formula--------------------------------

To better understand the following formulas review the rule of transposition in equations.
A multiplier may be removed from one side of an equation by making it a division on the other side, or a division may be removed from one side of an equation by making it a multiplier on the other side.

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1. Voltage and Current: Primary (p) secondary (s)
Power(p) = power (s) or Ep x Ip = Es x Is

A.	Ep =	Es x Is Ip		B.	Ip =	Es x Is Ep
C.	Is =	Ep x Ip Es		D.	Es =	Ep x Ip Is

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2. Voltage and Turns in Coil:
Voltage (p) x Turns (s) = Voltage (s) x Turns (p)
or Ep x Ts = Es x Ip

A.	Ep =	Es x Ip Ts		B.	Ts =	Es x Tp Ep
C.	Tp =	Ep x Ts Es		D.	Es =	Ep x Ts Tp

3. Amperes and Turns in Coil:
Amperes (p) x Turns (p) = Amperes (s) x Turns (s)
or Ip x Tp = Is x Ts

A.	Ip =	Is x Ts Tp		B.	Tp =	Is x Ts Ip
C.	Ts =	Ip x Tp Is		D.	Is =	Ip x Tp Ts

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Formula 1 − Electrical power equation: Power P = I × V = R × I2 = V2 ⁄ R  where power P is in watts, voltage V is in volts and current I is in amperes (DC).  If there is AC, look also at the power factor PF = cos φ and φ = power factor angle  (phase angle) between voltage and amperage.  Formula 2 − Mechanical power equation: Power P = E ⁄ t = W ⁄ t  where power P is in watts, Energy E is in joules, and time t is in seconds. 1 W = 1 J/s.  Power = force multiplied by displacement divided by time P = F × s / t or:  Power = force multiplied by speed (velocity) P = F × v.  Electrical Energy is E = P × t − measured in watt-hours, or also in kWh. 1J = 1N×m = 1W×s    Undistorted powerful sound is not found in these formulas. Please, mind your ears!  The eardrum and microphone diaphragms are really only moved by the waves of the  sound pressure. That does not do either the intensity, nor the power or the energy.  If you are in the audio recording business, it is wise not to care much about the  energy, power and intensity as the cause, care more about the effect of sound pressure  and sound pressure level on the ears and the microphones and the corresponding  audio voltage.  Sound pressure and Sound power – Effect and Cause  Very loud sounding speakers will have a lot of power, but look closer at the very  important efficiency of loudspeakers. This includes the typical question:  How many decibels (dB) are actually twice or three times as loud?  There is really no RMS power. The words "RMS power" are not correct. There is a  calculation of power which is the multiplication of a RMS voltage and a RMS current.  Watts RMS is meaningless. In fact, we use that term as an extreme shorthand for power in  watts calculated from measuring the RMS voltage. Please, read here:  Why there is no such thing as 'RMS watts' or 'watts RMS' and never has been.  Power is the amount of energy that is converted to a unit of time. Expect to pay more when  demanding higher power.

The true power factor and not the conventional 50/60 Hz displacement power factor

Electrical Measurement Definitions
QUANTITY	NAME	DEFINITION
frequency	hertz (Hz)	1/s
force	newton (N)	kg·m/s²
pressure	pascal (Pa) = N/m²	kg/m·s²
energy	work joule (J) = N·m	kg·m²/s²
power	watt (W) = J/s	kg·m²/s³
electric charge	coulomb (C) = A·s
voltage	volt (V) = W/A	kg·m²/A.s³
capacitance	farad (F) = C/V = A·s/V = s/Ω	A²·s4/kg·m²
inductance	henry (H) = Wb/A = V·s/A	kg·m²/A²·s²
resistance	ohm (Ω) = V/A	kg·m²A²·s³
conductance	siemens (S) = A/V	A²·s³/kg·m²
magnetic flux	weber (Wb) = V·s	kg·m²/A·s²
flux density	tesla (T) = Wb/m² = V·s/m²	kg/A·s²