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Category: GAIL Sample Paper

GAIL Sample Paper

GAIL Sample Paper

Aptitude Questions:

(1) 3.5 x 2.4 x ? = 42
(a) 1.5
(b) 0.2
(c) 0.8
(d) 1.2
(e) None of these

(2) 804357 = ?
(a) 98
(b) 89
(c) 96
(d) 93
(e) None of these

(3) 3 ? ÷16 x 24 = 186
(a) 98
(b) 89
(c) 96
(d) 93
(e) None of these

(4) (?)2 ÷ (0.04)2 x 5.6 = 117740
(a) 33.64
(b) 6.2
(c) 38.44
(d) 5.4
(e) None of these

(5) 9418 + ? + 1436 + 2156 = 5658
(a) 7523
(b) 7352
(c) 7232
(d) 7325
(e) None of these

(6) 9865 + ? + 3174 + 2257 = 19425
(a) 4047
(b) 4136
(c) 4129
(d) 4092
(e) None of these

(7) Each memory cell has a unique number assigned to it which is called as the ??.. of the cell
(a) Address
(b) Register
(c) Number
(d) path
(e) None of these

(8) RAM is also called as
(a) Read/Write Memory
(b) Long Memory
(c) permanent Memory
(d) Secondary Memory
(e) None of these

(9) A ??.. stores data or information temporarily and passes it on as directed by the control unit.
(a) Address
(b) Register
(c) Number
(d) Memory
(e) None of these

(10) Which of the following is NOT one of the four major data processing functions of a computer?
(a) gathering data
(b) Processing data into information
(c) analyzing the data or information
(d) storing the data or information
(e) None of these

(11) All of the following are examples of storage devices EECEPT:
(a) hard disk drives
(b) printers
(c) floppy disk drives
(d) CD drives
(e) Pen drives

(12) The CPU and memory are located on the:
(a) expansion board
(b) motherboard
(c) storage device
(d) output device
(e) display board

(13) A computer program that converts an entire program into machine language at one time is called a/an
(a) interpreter
(b) simulator
(c) character
(d) number
(e) None of these

(14) Computers process data into information by working exclusively with:
(a) multimedia
(b) words
(c) characters
(d) number
(e) None of these

(15) Computers manipulate data in many ways, and this manipulation is called????.
(a) upgrading
(b) processing
(c) batching
(d) utilizing
(e) None of these

Mechanical Technical Questions:

(1) What is fatigue or stress concentration factor

(2) What is the strength of riveted joint

(3) What kind of thread is used if power is to be transmitted in 1 direction only

(4) Overhauling case will have frictionb angle greater, equal or less than helix angle

(5) what combination of material is used 4 bearing manufacture

(6) Magnesium is added for which purpose

(7) For achieving hardness which procees should be carried(Annealing, normalising, martempering etc)

(8) Which welding is done for joining shank of a drill bit (Flash butt welding)

(9) What to be use for measuring angle and for locating the w/p at some angle

(10) How many nomenclatures are there to completely define a single poin cutting tool

GAIL Placement Paper
GAIL Electrical and Electronics Technical Paper

1. What will be the volume of EMF, if a 4 pole lap wound DC shunt motor rotates at the speed of 1500 rpm with a flux of 0.4 mWB and the total numbers of conductors are 1000?
a. 0.1 volts
b. 10 volts
c. 100 volts
d. 1 volts

2. What does a ceiling fan uses for its working?
a. Universal motor
b. Split ? phase motor
c. Capacitor start motor
d. Capacitor start and capacitor run motor

3. In a 3 phase synchronous motor
a. The speed of stator MMF is synchronous speed while that of rotor MMF is zero
b. The speed of stator MMF is always more than that of rotor MMF
c. The speed of stator MMF is always less than that of rotor MMF
d. Rotor and stator MMF are stationary with respect to each other

4. How many pole of motor shall be there in a 50 Hz ? 3 phase induction motor which has a full load of speed at 1440 r.p.m
a. 12
b. 8
c. 4
d. 6

5. Assuming a 100% efficiency of a 1:5 step ? up transformer has 120V across the primary and 600 ohms resistance across the secondary. Find the primary current equals?
a. 10 Amps
b. 5 Amps
c. 20 Amps
d. 0.2 Amps

6. What shall be the frequency of rotor induced emf in a slip of the induction machine is 0.02 and the stator supply frequency is 50 HZ?
a. 2500Hz
b. 10Hz
c. 1 Hz
d. 50 Hz

7. A 3 stack stepper motor with 12 numbers of rotor teeth has a step angle of
a. 8°
b. 24°
c. 12°
d. 10°

8. What will you change to control the temperature of resistance furnaces?
a. Circuit configuration
b. Applied voltage
c. Number of heating elements
d. All of the above

9. A single phase Hysteresis motor can run at
a. Synchronous and super synchronous speed
b. Sub synchronous speed only
c. Synchronous speed only
d. Synchronous and sub synchronous speed

10. Oil ? filled cable has a working stress of _________ kV/mm
a. 15
b. 12
c. 13
d. 10

11. Which type of drive motor is used in a mixer ? grinder?
a. Induction motor
b. Universal motor
c. DC motor
d. Synchronous motor

12. How will an RC differentiator act?
a. Band ? pass filter
b. Low ? pass filter
c. Band ? stop filter
d. High ? pass filter

13. What shall be the rotor frequency of a 3 phase 1000 RPM 6 pole induction motor with a slip of 0.04?
a. 6 Hz
b. 4 Hz
c. 2 Hz
d. 8 Hz

14. Which of the following capacitor is polarized?
a. Electrolytic
b. Mica
c. Plastic ? film
d. Ceramic

15. A balanced 3 ? phase, 50 Hz voltage is applied to a 3 phase, 4 pole induction motor, when the motor is delivering rated output the slip is found to be 0.05. What will be the speed of the rotor m.m.f relative to the rotor structure?
a. 25 r.p.m
b. 1500 r.p.m
c. 75 r.p.m
d. 1425 r.p.m

16. From the below mentioned option, on which is the efficiency of a transformer dependent?
a. Stray losses
b. Di ? electric losses
c. Core losses
d. Copper losses

17. The synchronous speed for a 3 phase 6 pole inductions motor is 1200 rpm. If the number of poles is now reduced to 4 with the frequency remaining constant, the rotor speed with a slip of 5% shall be
a. 1500 rpm
b. 1690 rpm
c. 1750 rpm
d. 1710 rpm

18. What is reduced when we laminate the armature of a SC machine?
a. Hysteresis loss
b. Friction and windage loss
c. Eddy current loss
d. Copper loss

19. The ability of a material to remain magnetized after removal of the magnetizing force is known as
a. Permeability
b. reluctance
c. hysteresis
d. retentivity

20. Electric resistance seam welding uses __________ electrodes.
a. Pointed
b. Disc
c. Flat
d. Domed
GAIL electronics and electrical
GAIL electronics and electrical questions with answers

1. A 3 stack stepper motor with 12 numbers of rotor teeth has a step angle of

____________.

120

24°
10°

Ans:DExplanation: Given m = 3, Nr = 12

Step angle = 360 / m x Nr = 360 /3 x 12 = 10°

2.Oil-filled cable has a working stress of __________ kV/mm

10
12
13
15
Ans:D

Explanation: This is defined by dielectric strength of mineral oil i.e. 15 kV/mm.

3. The rotor frequency for a 3 phase 1000 RPM 6 pole induction motor with a slip of 0.04 is________Hz

8
4
6
2
Ans:D

Explanation: Given: N=1000 rpm ; P= 6; s= 0.04;

and f = N_P/ 120

= 1000_6/120

= 50 Hz

Rotor frequency fr=s_f = 0.04_50

= 2.0 Hz

4. The synchronous speed for a 3 phase 6-pole induction motor is 1200 rpm. If the number of poles is now reduced to 4 with the frequency remaining constant, the rotor speed with a slip of 5% will be _________.

1690 rpm
1750 rpm
1500 rpm
1710 rpm
Ans:D

Explanation: Given : Ns1 =1200 , P1= 6,

P2 = 4, s = 0.05,

Frequency f = Ns_P/120

= 120_6/120 = 60 Hz

rotor frequency f/ = s.f = 0.05 _60 = 3.0 Hz

Now, Ns2 = 120 _60 /4 = 1800 and Ns – N = 120 f / P2

Therefore, N=Ns- 120 f / P2 = 1800-120_0.05_60/4 = 1800-90 = 1710

5. The efficiency of a transformer is mainly dependent on

core losses.
copper losses
stray losses.
dielectric losses.
Ans:A

6. A synchronous motor is operating on no-load at unity power factor. If the field

current is increased, power factor will become

Leading & current will decrease
Lagging & current will increase.
Lagging & current will decrease
Leading & current will increase.
Ans:A

Explanation: Initially synchronous motor is operating at no load and unity power factor. When field current increases, the excitation will increase. Therefore, p.f will be leading and current will be I CosF < I

7. If the phase angle of the voltage coil of a directional relay is o 50 , the maximum torque angle of the relay is

130
100

50

25

Ans:C
Explanation: Torque _ Power

Power _ Voltage

Therefore, It has same angle as ‘V’ ha

8. A 220/440 V, 50 Hz, 5 KVA, single phase transformer operates on 220V, 40Hz supply with secondary winding open circuited. Then

Both eddy current and hysteresis losses decreases.
Both eddy current and hysteresis losses increases.
Eddy current loss remains the same but hysteresis loss increases.
Eddy current loss increases but hysteresis loss remains the same.

Ans:A
Explanation: Wh = khfBm

1.6 and We = kef2Bm

2.k

Therefore, hysteresis and eddy current losses will be decreased when frequency decreases.

9. Electric ovens using heating elements of _______________ can produce temperature upto 3000°C.

Nickel
Graphite
Chromium
Iron
Ans:C

Explanation: Chromium has high melting point.

10. Electric resistance seam welding uses __________ electrodes.

Pointed
Disc.
Flat
Domed
Ans:B

Explanation: Disc type electrodes are used for electric resistance seam welding.

11. The line trap unit employed in carrier current relaying:

offers high impedance to 50 Hz power frequency signal
offers high impedance to carrier frequency signal
offers low impedance to carrier frequency signal
Both (A) & (C)

Ans:B

Explanation: The line trap unit employed in carrier current relaying offers high impedance to

carrier frequency signal.

Because carrier frequency range is 35 km – 500 kHz

XL = 2_ f l

Where f increases XL will also increases

12. The temperature of resistance furnaces can be controlled by changing the:

applied voltage
number of heating elements
circuit configuration
All of the above
Ans:D

Explanation: Temperature of resistance furnaces can be controlled by changing either applied voltage or by number of heating elements or by circuit configuration.

13. A single phase Hysteresis motor

can run at synchronous speed only
can run at sub synchronous speed only
can run at synchronous and super synchronous speed
can run at synchronous and sub synchronous speed
Ans:A

Explanation: The rotor revolves synchronously because the rotor poles magnetically lock up with the revolving stator poles of opposite polarity

14. The armature of a dc machine is laminated to reduce:

Eddy current loss
Hysteresis loss
copper losses
friction and windage losses
Ans:A

Explanation: Thinner the laminations, greater is the resistance offered to the induced e.m.f., smaller the current and hence lesser the I2R loss in the core.

15. For LV applications (below 1 kV), ______________ cables are used.

Paper insulated.
Plastic.
Single core cables.
Oil filled.
Ans:C
Explanation: For low voltage applications single core cables are suitable.

16. The ability of a material to remain magnetized after removal of the magnetizing force is known as

Permeability
reluctance
hysteresis
retentivity
Ans:D

17. When a solenoid is activated, the force that moves the plunger is

an electromagnetic field
a permanent magnetic field
varying voltage
a steady current
Ans:A

18. Which of the following capacitors is polarized

mica
ceramic
plastic-film
electrolytic
Ans:D

19. In a series resonant band-pass filter, a lower value of Q results in

a higher resonant frequency
a smaller bandwidth
a higher impedance
a larger bandwidth
Ans:D

20. A steady-state condition is reached when

the output voltage reaches the average value of the input voltage
the output voltage reaches the input voltage
the output voltage reaches approximately 63% of the input voltage
the output voltage reaches the effective value of the input voltage
Ans:A

21. An RC differentiator acts as a

low-pass filter
high-pass filter
band-pass filter
band-stop filter
Ans:B

22. A balanced three-phase, 50 Hz voltage is applied to a 3 phase, 4 pole, induction motor. When the motor is delivering rated output, the slip is found to be 0.05. The speed of the rotor m.m.f. relative to the rotor structure is

1500 r.p.m.
1425 r.p.m.
25 r.p.m.
75 r.p.m.
Ans:D

Explanation: NS = 120f /P = 120 x 50 /4 =1500rpm

N = NS ( 1-s) = 1500 (1-0.05) = 1425

\relative speed = 1500 – 1425 = 75 rpm

23. A ceiling fan uses

split-phase motor.
capacitor start and capacitor run motor
universal motor.
capacitor start motor.
Ans:D

24. The drive motor used in a mixer-grinder is a

dc motor.
induction motor.
synchronous motor.
universal motor.
Ans:D

25. A 1:5 step-up transformer has 120V across the primary and 600 ohms resistance across the secondary. Assuming 100% efficiency, the primary current equals

0.2 Amp.
5 Amps
10 Amps.
20 Amps.
Ans:A
Explanation: I1= V1 /R1 = 120/600 = 0.2 (h = 100%, losses are zero \V1 = VR = I1R1)

26 . 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

4.
6.
12
8.
Ans:A

Explanation: N= Ns (1-S) = NS –NS x S

1440 = Ns (1-S)

Ns = 1440 / (1-S)

Ns = (120 f/ p) = 120 x 50/p = 6000 p

Ns will be closer to N i.e 1440

When P=2 ; Ns = 3000 rpm , not close to N

When P=4 ; Ns = 1500 rpm , it is closer to N

Therefore P =4 for N=1440

27 In a 3-phase synchronous motor

the speed of stator MMF is always more than that of rotor MMF.
the speed of stator MMF is always less than that of rotor MMF.
the speed of stator MMF is synchronous speed while that of rotor MMF is zero
rotor and stator MMF are stationary with respect to each other.
Ans:D

Explanation: Because, Motor is magnetically locked into position with stator, the rotor poles are engaged with stator poles and both run synchronously in same direction Therefore,

rotor & stator mmf are stationary w.r.t each other.

28 In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltage in the two cases.

delta side lags by -30°.
star side lags by -30°.
delta side leads by 30°.
star side leads by -30°.
Ans:C

Explanation: This is vector group and has +30° displacement. Therefore, delta side leads by +30°.
29. 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?
10 Hz.
50 Hz.
1 Hz.
2500 Hz.
Ans:C
Explanation: Given : s = 0.02 ; f = 50 Hz

Therefore, frequency of rotor induced emf = s f

= 0.02 x 50 = 1.0 Hz

30. A 4 pole lap wound dc shunt motor rotates at the speed of 1500 rpm, has a flux of 0.4 mWb and the total number of conductors are 1000. What is the value of emf?

100 Volts.
0.1 Volts.
1 Volts.
10 Volts.
Ans:D

Explanation: Given N = 1500 rpm, F = 0.4 mWb, Z = 1000, P = 4, & A= 4

Therefore, Eb = NFPZ / 60 A

= 1500 x 0.4 x 4 x 1000 x 10-3 / 60 x 4

= 60/6 = 10 volts
{C}{C}

GAIL in Telemetry(ECE), I am writing this for reference for all ECE students. Question paper consists of 2 sections. 1) Domain knowledge-100
2) Aptitude & General Awareness-50 The paper is moderate, not too easy or not too difficult. The peculiar thing i observed is they gave questions from all subjects question paper covered all subjects like Digital design, Network Theory, Communication(digital and analog), electrical measurements, electronics measurements, antennas, optical communication, microwave, electronic devices etc. We can’t neglect any subject. I observed more questions from electronic & electrical measurements, optical comm, antennas. General Awareness is easy only. Aptitude all can do.
Out of 50 nearly 45 everyone can do. Some of the technical questions are as below: 1) One question on image signal frequency.
2) Find channel capacity given s/n ration and B.W
3) In resonant ckt value of capacitance, give ‘Q’ value and ‘w’ value

4) In digital E5 decimal equivalent? 5) For FET find gain 6) 2 stage cascaded gain BW product is________of single stage gain BW product
1) less 2) more 3) same
7) Short waves range
8) More wavelength for which waves
1) X rays 2) Y rays 3) UV
9) Which connects ‘n’ input and gives ‘n’ outputs?
Ans: Modem
10) Which have more fan out?
Ans: CMOS

11) One question on feedback gain formula

12) ‘Q’ value,’Qdash’ value given what will be values of J=? K=?

13) Which is delay flipflop?
Ans: D-flipflop

14) Race-around condition not present in?
Ans: Master-Slave flip flop General Knowledge: 1) Which of following is not west flowing river?
Ans: Cavery
2) Rupee Symbol creator?
3) Canadian Grand prix winner?
4) Recent oil spill in Mumbai, govt fined how much amount to company in billions?
5) Compound interest problem
6) Gandhi’s belonging charaka got by whom?
Ans: French Company
7) One Comprehension
8) Fill blanks with suitable words
9) 2 problems from age problems
Sorry Guys i unable to recall. Hope this gives a minimum idea about GAIL for ECE people.
Though this time for ECE only 2 posts, i don’t have hopes, hope future ECE guys benefit from this overview.
Please concentrate more on Optical, electrical and electronic measurements, antennas to score more.

GAIL Question-Paper\

GAIL Model Test Paper

1. The ratio of the no. of white balls in a bag to that of black balls is 1:2. If 9 grey balls are added the ratio of nos. of white, black and grey become 2:4:3. How many black balls were in the bag?
a) 6
b) 9
c) 12
d) 8

2. There are 2 toy cars facing each other at a distance of 500 cm from each other. Each car moves forward by 100 cm at a speed of 50 cm/s and then moves backward by 50 cm at a speed of 25 cm/s. How long will it take for the cars to collide?
a) 12s
b) 14s
c) 16s
d) 13s

3. Find the greatest no. that will divide 964,1238 and 1400 leaving remainder of 41,31 and 51 resp.
a) 58
b) 64
c) 69
d) 71

4.A person gives a secret to two other persons in 5 minutes. How long will he take to tell the secret to 768 people.

5.There are 40 seats in a bus. People agree to share the money for the number of seats. The total money comes to 70.37. how many seats were free.

Ans. 9 seats.Rs.2.27

6. A works thrice as much as B. If A takes 60 days less than B to do a work then find the number of days it would take to complete the work if both work together?

Ans. 221/2days

7. In 60 reems of paper 40 reems were utilized then what percent will remain…

ans:33.33%

8. A started at 9.00 am with 6 mph and B started at 9.30 am with 8mph in the same direction. At what time they will meet…

ans:11.00am

9. In a storage stall of 5x3x2inch.How many blanks of size 2x1x1inch can be stored..

ans:15

10. A company requires 11,500 strength. present employees are 200 women , men and 6500 unmarried To reach the target how many women required to maintain the same ratio

ans : 300

11. Centre of gravity of hemi sphere?

Ans: 3r/8

12. Time of flight of a projectile?

13. Modulus of elasticity for a tapering section?

14. For what angle does maximum shear stress on a body exist when body is subjected to stress in one plain?

15. If a cantilever beam is loaded wid point load at its free end when the load increases at which section it will break first?

16. What kind of rivet arrangement is called as diamond riveting?

17. Which among dese is not dimensionless?
a) Absolute viscosity
b) Specific volume
c) Specific gravity

18. Laminar flow characteristic related question?

19. Specific speed of turbine?

20. Unit power of turbine?

21. Discharge through a reciprocating pump for single and double acting

22. Which one is intensive property?
a) Entropy
b) Enthalpy
c) Density

23. Which among these has highest efficiency?
a) otto
b) Diesel
c)dual

24. What is equivalent length of simple pendulam which gives the same frequency as compare to compound pendulam.?

25. What is endurance limit ratio?
GAIL Question-Paper
GAIL Electrical & Electronics Engineering Sample Paper

1.Consider the following expressions indicating the step or impulse response of an initially relaxed control system-
a.) (5 ? 4e-2t) u(t)
b.) (e-2t +5) (u(t))
c.) V(t) + 8e-2t u(t)
d.) V(t) + 4e-2t 4(t)

2.Which is the following relate to rational transfer function of a system-
a.) Ratio of Fourier transform of output to input with zero initial conditions.
b.) Ratio of Laplace transform of output to input with zero initial conditions.
c.) Laplace transform of system impulse response.

3. Laplace transform of system unit step response select the correct answer using the codes given below. Codes
a.) 1 and 4
b.) 2 and 3
c.) 1 and 3
d.) 2 and 4

4.For the signal g (t) ? 10 cos (50 pt) cos2 (150at) The Nyquist sampling state in t seconds is
a.) 150 samples per second
b.) 200 samples per second
c.) 300 samples per second
d.) 350 samples per second

5.In the case of a 70 MHz 1F carries for a transponder band width of 36 MHz; energy must lie between ? MHz.
a.) 34 and 106
b.) 52. And 88
c.) 106 and 142
d.) 34 and 142

6.Radar used to eliminate clutter in navigational application is ?
a.) Pulse radar
b.) Tracking radar
c.) MTI radar
d.) Mono pulse radar

7.The 1.55 mm windows is not yet in use with fiber optic systems because ?
a.) The attenuation is higher than at 0.85 mm
b) The attenuation is higher than at 1.3mm
c.) Suitable laser devices have not yet been developed
d.) It does not lend itself to wavelength multiplexing

8.Pre-emphasis in FM systems involves-
a.) Compression of the modulating signal
b.) Expansion of the modulating signal
c.) Amplification of lower frequency components of the modulating signal.
d.) Amplification of higher frequency components of the modulating signal.

9.In a terrestrial microwave system transmission of signals is achieved through-
a.) reflection from the ionosphere
b.) line of sight mode
c) reflection from the ground
d.) diffraction from the stratosphere.

10.Casse grain feed is used with a parabolic reflector to
a.) increase the gain of the system
b). increase the bandwidth of the system
c.) reduce the size of the main reflector
d.) allow the feed to be placed at a convenient point.

11.In most microwave communication link rain drop attenuation is caused due to-
a.) scattering of microwaves by water drops of specific size.
b) scattering of microwaves by a collection of droplets acing as a single body.
c.) absorption of microwaves by water and consequent heating of the liquid
d.) absorption of the microwaves by water vapor in the atmosphere.

12.When a (75 ? j40)W load is connected to a coaxial line of Z0 = 75 W at 6MHz then the load matching on the line can be accomplished by connecting-
a.) A short ? circuited stub at the load
b.)An inductance at the load
c. )A short circuited stub at a specific distance from the load
d.)none of the above

13.As compared to analog multimeters, digital Multimeters’s are ?
a.) less accurate
b.) more accurate
c.) equally accurate
d.) none.

14.When a signal of 10 mV at 75 MHz is to be measured then which of the following instruments can be used ?
a.) VTVM
b.) Cathode ray oscilloscope
c.) Moving iron voltmeter
d.) Digital multimeter

15.Amplifier of class B has high theoretical efficiency of 78.5 percent because-
a.) It is biased almost to saturation
b.)Its quiescent current is low
c.)It?s output is an exact replica of it?s input
d.)It is biased well below cut off

16.The coupling that produces minimum interference with frequency response is-
a.) Direct coupling
b.) Impedance coupling
c.) R C coupling
d.)Transformer coupling

17.A superconductor is a ?
a.) A material showing perfect conductivity and Meissner effect below a critical temperature
b.) A conductor having zero resistance
c.) A perfect conductor with highest di-magnetic susceptibility
d.) A perfect conductor which becomes resistance when the current density through it exceeds a critical value

18.When an inductor tunes at 200 KHz with 624 pF capacitor and at 600 KHz with 60.4 pF capacitor then the self capacitance of the inductor would be ?
a) 8.05 pF
b) 10.05pF
c.) 16.01pF
d.) 20.01pF

19.The Q of a radio coil ?
a.) is independent of frequency
b.) increases monotonically as frequency increases
c.) decreases monotonically as frequency increases
d.) increases upto a certain frequency and then decreases beyond that frequency

20.When a generator of internal impedance and operating at 1GHz feeds a load via a coaxial line of characteristic impedance 50 ohm then the voltage wave ratio on the feed line is ?
a.) 0.5
b.) 1.5
c.) 2.5
d.) 1.75

21.The coding system typically used in digital telemetry is ?
a.) PPM (pulse position modulation)
b.) PAM (pulse amplitude modulation)
c.) PCM (pulse code modulation)
d.) PDM (pulse duration modulation)

22.Radiation pyrometers are used for the measurement of temperature in the range of ?
a.) -2000C to 5000C
b.) 00C to 5000C
c.) 5000C to 12000C
d.) 12000C to 25000C

23.RF amplifier of an A.M. receiver is normally biased in ?
a.) Class ‘A’
b.) Class ‘b’
c.) Class ‘C’
d.) None

24.The value of gate voltage for the operation of enhancement of only N channel MOSFET has to be ?
a.) High positive
b.) High negative
c.) Low positive
d.) Zero

25. A synchronous motor works as a synchronous condenser if
a.) underexcited
b.) overexcited
c.) excited with 100% excitation
d.) unexcited