If CRICKET is coded as FULFNHW, then BRIDE would be coded as-
C→+3 FR→+3 UI→+3 LC→+3 FK→+3 NE→+3 HT→+3 W
Similarly,
B→ER→UI→LD→GE→H
Hence, the correct option is (B)
Which one of the following diagrams best depicts the relationship among Pigeons, Birds and Dogs?
Hence, the correct option is (A)
In a certain language, 'tom kun sud’ means ‘dogs are barking, ‘kun jo mop’ means ‘dogs and horses’, and ‘mut tom ko’ means ‘donkeys are mad’, Which word in that language means ‘barking’?
In the first and third statements, the common code-word is ‘torn’, and the common word is ‘are’. So, ‘tom’ means ‘are’. Thus in the first statement, ‘sud’ means ‘barking’.
Hence, the correct option is (A)
DIRECTIONS: In the following question, a statement followed by two conclusions is given. Select a conclusion that follows the statement.
Statement:
Heena told Maya that a ghost lived on the Neem tree in the outskirts of the villa.
Conclusions:
I. Neem trees grow only on the outskirt of the villa.
II. All the ghosts live on Neem tree.
Hence, the correct option is (D)
Dhanesh walks 50 m east, and then he turns to his right and walks 30 metres. Now, in which is he from his starting point?
Dhanesh is in the southeast direction from his starting point.
Hence, the correct option is (D)
B is the only child of the only daughter of C’s paternal grandfather. How is C’s father related to B?
B is the child of the sister of C's father. Therefore, C’s father is the maternal uncle of B.
Hence, the correct option is (A)
Three of the following four are alike in a certain way, and so form a group. Which is the one that does not belong to that group?
Hence, the correct option is (D)
DIRECTIONS: A piece of paper is folded and cut as shown below in the questions figure. From the given answer figures, indicate how it will appear when opened?
Hence, the correct option is (B).
DIRECTIONS: In the following figure circle represents literate, and the bigger rectangle represents healthy, and the smaller rectangle represents rich people.
Which number represents those literates who are neither rich nor healthy?
Hence, the correct option is (A)
Which one of the following figures represents the relationship among Males, Fathers, Advocates?
All fathers are males, Few males and fathers can be advocates.
Vishal walks 2 km towards South. He then turns right and walks 3 km; he now turns left and walks 5 km. Further, he moves 2 km after turning to the left. In which direction is he facing?
He is facing towards the east.
Hence, the correct option is (B).
In a row In East-West direction, Dipika is on 11th position from West and Sudesh is on 15th position from East end. If they exchange their positions, Sudesh will be on the 9th position from the East end. How many persons are there In the row?
Total number of persons in the row =11+9−1
=20−1=19
Hence, the correct option is (B)
Choose the odd number from the given alternatives-
3375=(15)3
1728=(12)3
Except 2890, all the other numbers are perfect cubes.
2890 is the odd number.
Hence, the correct option is (D).
DIRECTIONS: In the given diagram, the circle represents wise men, the square represents experienced men, the triangle represents teachers. Which region represents teachers who are wise as well as experienced?
Hence, the correct option is (D)
B is the brother of A, whose only sister is the mother of C, D is the maternal grandmother of C. How is A related to D?
Hence, the correct option is (B)
Maya starts from point T, walks straight to point U, which is 4 ft away. She turns left at 90° and walks to W, which is 4 ft away, turns 90° right and goes 3 ft to P, turns 90° right and walks 1 ft to Q, turns left at 90° and goes to V, which is 1 ft away and once again turns 90° right and goes to R, 3 ft away. What is the distance between T and R?
Distance between T and R
= TR=TU+UR
=TU+PW+QV
=(4+3+1)ft =8 ft.
Hence, the correct option is (D)
If QKKQUGQL is the code for OMISSION, which word is coded as RYVIWZB?
Hence, the correct option is (A)
Directions: What will come in place of the question mark (?) in the following number series?
8, 27, 141, 996, ?
8 × 3 + 3 = 27
27 × 5 + 6 = 141
141 × 7 + 9 = 996
996 x 9 + 12 = 8976
In the following question, select the odd one out.
Hence, the correct option is (A)
Select the answer figure in which the question figure is hidden.
Hence, the correct option is (B)
A woman has only 25 p and 50 p coins in her bag. If in all, she has 40 coins which total Rs.12.75, then the number of 50 p coins is?
Then x+y=40....... (1)
And
2x + y = 51....... (2)
By solving (1) and (2), we get
x = 11
Hence, the correct option is (C).
DIRECTIONS: In each of the following questions, four words have been given, out of which three are alike in some manner, and the fourth one is different. Choose out the odd one.
Hence, the correct option is (C)
The city A is situated 2 miles away in the northwest direction from the city B. C is situated at 2 miles away in the South-west direction from A. D is situated 2 miles away in the northwest direction from C. E is located 2 miles away in the southwest direction from D. In which direction is E located in relation to B?
In the figure given above, E is located to the west in relation to B.
Hence, the correct option is ©
Which of the answer figure is exactly the mirror image of the given figure when the mirror is held on the line AB?
Question Figures
Hence, the correct option is (B)
DIRECTIONS: In the following question, select the answer figure In which the question figure Is hidden/embedded.
Question Figure
Hence, the correct option is (D)
If HOSPITAL is written as 32574618 in a certain code, how would POSTAL be written in that code?
H→3 O→2 S→5 P→7 I→4 T→6 A→1 L→8
According to direct letter coding,
P→7 O→2 S→5 T→6 A→1 L→8
So, the code is 725618.
Hence, the correct option is (B).
DIRECTIONS: In the following question, a piece of paper is folded in the manner shown in the question figure(s). Select the figure out of the answer choices showing the unfolded pattern after the punches (cut).
Hence, the correct option is (C).
‘K’ walked 5 metres towards North, took a left turn and walked for 10 metres. He then took a right turn and walked for 20 metres, and again took a right turn and walked 10 metres. How far is he from the starting point?
Hence, the correct option is (C)
In a row of students, if John, who is 16th from the left, and Johnson, who is 8th from the right, interchange their positions, John becomes 33rd from left. How many students are there in the row?
Total number of students
= 33 + 8 - 1
= 40
Hence, the correct option is (C)
In a certain code language, ‘col tip mot’ means ‘singing is appreciable’, ‘mot baj min’ means ‘dancing is good’ and ‘tip nop baj’ means ‘singing and dancing’, which of the following means ‘good’ in that code language?
‘mot baj min’=‘dancing is good’______(2)
‘tip nop baj’=‘singing and dancing’_____(3)
From(1)and(2), mot=is
From(2)and(3),baj=dancing
From(2) min=good
Hence, the correct option is (B)
Pavan walked 30 meters towards West, took a left turn and walked 20 meters. He again took a left turn and walked 30 meters. He then took a right turn and stopped. Towards which direction was he facing when he stopped?
Hence, the correct option is (A)
DIRECTIONS: Choose the odd one out from the given alternatives.
Pattern is-
S U N D A Y
1 2 3 4 5 6
Y A D S U N
6 5 4 1 2 3
Hence, the correct option is (B)
DIRECTIONS: In the following questions, four figures are given. Three are similar in a certain way, and so form a group. Find out which one of the figures does not belong to that group.
Hence, the correct option is (C)
Directions: In each of the following questions, select the related word/letters/number from the given alternatives.
NEVER : SELDOM :: ALWAYS: ?
Find the missing term
24, 60, 120, 210, ?
So, missing term = 210 + [6 × (6 + 15)] = 210 + 126 = 336.
Hence, the correct option is (B)
Two trucks start from the opposite points of the main road, 300 km apart. The first truck runs for 50 km and takes a right turn, and then runs for 25 km. It then turns left and runs for another 50 km, and takes the direction back to reach the main road. In the meantime, due to a minor breakdown, the other truck has run only 75 km along the main road. What would be the distance between the two trucks at this point?
Let T1 and T2 are two trucks with A and P as their starting points, respectively.
Required distance = AP - (AE + PQ) = 300 — (100 + 75) = 125km
Hence, the correct option is (B)
Find the missing number in a series given below:
9, 27, 31, 155, 161, 1127, ?
So, the missing term is 1127 + 8 = 1135.
Hence, the correct option is (B)
Lokesh is taller than Gagan but not shorter than Abhishek. Abhishek and Suresh are of the same height. Lokesh is shorter than Lalit. Amongst the boys, who is the tallest?
Lokesh > Abhishek
Abhishek = Suresh
Lokesh > Abhishek = Suresh
Lalit > Lokesh
Lalit > Lokesh > Abhishek = Suresh
OR
Lalit > Lokesh > Gagan
Hence, the correct option is (B)
DIRECTIONS: In the following questions, find the missing letters in the given series.
AOP, CQR, EST, GUV,?
Pattern 2:
Pattern 3:
So, the missing letters are IWX.
Hence, the correct option is (C)
DIRECTIONS: In each of the following equation, which one of the following interchange of signs would make the given equation correct:
10 + 10 ÷ 10 – 10 × 10 = 10
10 + 10 ÷ 10 – 10 × 10 = 10
After interchanging + and ×,
10 x 10 ÷ 10 – 10 + 10 = 10
⇒10×1−10+10=10⇒10=10.
Hence, the correct option is (C)
In a certain code, MAIN is written as IMNA and GOAL is written as AGLO. How is DUSK written in that code?
Similarly-
Hence, the correct option is (A)
How many hexagons are there in the figure given below?
∴ Total hexagons = CDEKLM, CEUKMQ, CFHJMQ, BEUKNP, BFHJNP = 5
Hence, the correct option is (B)
If every Sunday of any month is on the fourth, eleventh eighteenth and twenty-fifth, then which day will be the last day of the month if the first day of the month is Thursday?
Hence, the correct option is (D)
DIRECTIONS: Study the information carefully and answer the questions.
N, O, P, Q, R, S, T and U are sitting around a circular area at equal distances between each other but not necessarily in the same order. Some people face the centre while some face outside (i.e. in a direction opposite to the centre).
R sits second to the right of T.T face the centre. O sits third to the left of R. R and O face opposite directions. R does not face the centre. Immediate neighbours of O face the centre. P sits second to the right of O. U sits to the immediate left of P. N sits second to the left of Q. Q faces the same direction as O. Q is not an immediate neighbour of T. Immediate neighbours of R face opposite directions. (i.e. if one neighbour faces the centre, the other neighbour faces outside.
Who sits second to the left of U?
S sits second to the left of U.
Hence, the correct option is ©
DIRECTIONS: Study the information carefully and answer the questions.
N, O, P, Q, R, S, T and U are sitting around a circular area at equal distances between each other but not necessarily in the same order. Some people face the centre while some face outside (i.e. in a direction opposite to the centre).
R sits second to the right of T.T face the centre. O sits third to the left of R. R and O face opposite directions. R does not face the centre. Immediate neighbours of O face the centre. P sits second to the right of O. U sits to the immediate left of P. N sits second to the left of Q. Q faces the same direction as O. Q is not an immediate neighbour of T. Immediate neighbours of R face opposite directions. (i.e. if one neighbour faces the centre, the other neighbour faces outside.
Four of the following five are alike in a certain way based on the given seating arrangement, and so form a group. Which is the one that does not belong to that group?
N does not belong to that group because N is facing outside and the other facing inside the centre.
Hence, the correct option is (D)
DIRECTIONS: In the following questions, find the missing letters in the given series.
CDE, IJK, NOP,?
The missing letters are RST.
Hence, the correct option is (B)
DIRECTIONS: Select the related letters,word/number/figure from the given alternatives.
11:121:110:: 15:225 : 210::?
(11)2= 121, and 121—11 = 110
(15)2= 225, and 225— 15 =210
Similarly,
(19)2 = 361 and 361 — 19=342
Hence, the correct option is (B)
DIRECTIONS: Find out missing number/letter/number and letter from the following given options/figures.
2 x 3=6
3 x 4 = 12
4 x 5 = 20
5 x 2 = 10
Then, missing number is 20
Hence, the correct option is (B)
DIRECTIONS: In the question below, select the related figure from the given alternatives.
A is opposite to F
E is opposite to C
B is opposite to D
Hence, the correct option is (D)
DIRECTIONS: A word is represented by only one set of numbers as given in any one of the alternatives. The sets of numbers given in the alternatives are represented by two classes of the alphabet, as shown in the given two matrices. The columns and rows of Matrix-I are numbered from 0 to 4, and that of Matrix-II are numbered from 5 to 9. A letter from these matrices can be represented first by its row and next by its column; for example, 'N’ can be represented by 21, 67 etc., and ‘R’ can be represented by 57, 66 etc. Similarly, you have to identify the set for the word ‘METER’.
E ⇒ 20, 40, 78, 97
T ⇒ 41, 59, 68, 77
R ⇒ 01, 13, 22, 57, 66
Hence, the correct option is (B)
Which of the following was not done during the time of Lord Curzon?
Who led the English Army in the Battle of Buxar?
Who was elected the President of All India Workers and Peasants Party in Calcutta in 1928?
Which of the following events is NOT considered for the time being of Viceroy Lord Lytton?
Who of the following Viceroy is related to the Burma war?
After which war did Babur hold the title of Ghazi?
In which language were the Buddhist literary works generally written?
Who among the following is NOT a famous dancer of Bharatanatyam?
During _____________ motion of an object along a straight line, the velocity remains constant with time.
1kWh = _________ x 106J.
As an object falls freely its ___________________.
In a ___________________ wave particles of the medium vibrate in a direction perpendicular to the direction of wave propagation.
When the vibrating object moves backwards, it creates a region of low pressure in the medium called _______________.
Ethanol reacts with sodium leading to the evolution of which gas?
Atomic number is always equal to ______.
An atom can achieve octet by ______.
I. Sharing electron
II. Gaining electron
III. Losing electron
What is formed when a helium atom loses one electron?
Which of the following electromagnetic waves has minimum wavelength?
Salivary amylase breaks down ______.
Which of the following represents the pair of sex chromosomes in men?
Pepsin is an enzyme that digests ______.
How is the nitrogen taken up by the plants?
I. In the form of inorganic nitrates or nitrites
II. In the form of organic compounds
III. Directly taken up from the atmosphere
Why do plants close stomata when it does NOT need carbon dioxide for photosynthesis
In Microsoft Word, _______________ provides information about the current document.
Web applications are designed to interpret _____________ to display text, images etc.
SEBI is ___________.
Which one among the following administers the International Development Association (IDA)?
Which of the following is NOT a measure of the Human Development Index?
Education - expected years schooling for school-age children and average years of schooling in the adult population and Income - measured by Gross National Income (GNI) per capita (PPP US$).
The term "Smart Money" broadly refers to ___________.
Visible and invisible items of debit and credit are the part of___________.
Which of the following cities is closest to the Equator?
Which of the following is NOT correctly matched?
Which of the following is a Block Mountain?
Why is Carbon Monoxide a pollutant?
The outermost range of Himalayas is called_________.
Which of the following causes rainfall during winters in the northwestern part of India?
The largest herbarium of India is located at -
The longest sea beach in India is -
What is the minimum age required to become a member of the municipality?
Part of XVII of India Constitution deals with ______.
The constitution of India refers to the budget as the ______.
The India Parliament should meet at least ______.
After how much time the laws made by Parliament on the state subjects during a National Emergency become inoperative and cease to operate?
Who has been elected as the new President of the World Bank?
Project-75 India, sometimes seen in the news, is associated with which Indian armed force?
What is the theme of the 2019 World Health Day (WHD)?
Which of the following ships has become the first-ever Coast Guard ship to visit Indonesia?
Who has become the youngest Indian woman to win on Ladies European Tour (LET)?
Which country is hosting the 2019 SAFF Women's Championship?
Which of the following Indian companies has won the 'Global Slag Company of the Year' award?
Tata Steel has been named as the 'Global Slag Company of the Year' at the 14th Global Slag Conference and Exhibition 2019 in Aachen, Germany.
If the frequency of 3-phase supply to the stator of a 3-phase induction motor is increased, then synchronous speed………….
For a 3-phase, 4-pole, 50 Hz synchronous motor, the frequency, no. of poles, and the load torque are all halved. The motor speed will be-
What is the use of the circuit shown in the figure below?
Resistance is connected in one phase of three phase induction motor is to provide smooth starting to the motor.
The RMS value of high frequency AC signal applied to a PMMC instrument is 120V. then reading of PMMC instrument will be –
The permanent magnet moving coil instrument or PMMC type instrument uses two permanent magnets in order to create stationary magnetic field. These types of instruments are only used for measuring the DC quantities as if we apply AC current to these type of instruments the direction of current will be reversed during negative half cycle and hence the direction of torque will also be reversed which gives average value of torque zero.
In the power system, the resonance rarely occurs at the supply frequency because
Resonance in an electrical system occurs when inductive reactance of the circuit becomes equal to capacitive reactance of the circuit. Resonance causes high voltages in the electrical system. In transmission lines, the capacitance is very small as compared to inductance so that resonance rarely occurs.
In case of slow developing faults transformer, the Buchholz relay
In case of slow developing faults within the transformer, the heat due to fault causes the decomposition of some transformer oil in the main tank. When a predetermined amount of gas gets accumulated, it exerts pressure on the float to complete the alarm circuit.
The value of voltage across the diode in the figure given below is-
There will be no current in the circuit as the diode is reverse biased.
So, the whole voltage will cross the diode.
In 132 kV system, the phase to ground capacitance is 0.01 μA, and inductance is 6H. The voltage that appears across the contacts of circuit breaker if a magnetizing current of 10 A is interrupted is
We have three resistance each of value 1 Ω, 2 Ω and 3 Ω. If all the three resistances are to be connected in a circuit, how many different values of equivalent resistance are possible?
Eight different values can be obtained if they are connected in different ways.
All three in series (1 combination)
All three in parallel (1 combination)
One in series two in parallel (3 combination)
Two in series one in parallel ( 3 combination)
Total Eight different values can be obtained if they are connected in different ways.
All three in series (1 combination)
All three in parallel (1 combination)
One in series two in parallel (3 combination)
Two in series one in parallel ( 3 combination)
Total = 1 + 1 + 3 + 3 = 8
A 4-pole, the 3-phase induction motor is running at 4% slip at full load. If the speed of the motor is 750 rpm, the supply frequency is-
If the speed of a universal motor in AC operation is (N AC) and in DC operation is N DC) (and I = current, V = supply voltage, r = resistance, X = reactance, = power factor) then the speed ratio-
For DC supply,
From equation (1) and (2)
On solving we will get finally,
A capacitor stores energy in the form of
A capacitor stores electrostatic energy whereas an inductor stores energy in the form of magnetic energy.
If the inductance and capacitance of a power system are respectively 1H and the instantaneous value of interrupted current is 10A, then the voltage across the breaker contacts will be -
If four capacitors connected in parallel, the net capacitance is-
On what factor does the specific resistivity of the material depends
Specific resistance is defined as the property of the material which depends on the temperature and chemical composition of the material.
A lossy capacitor with a loss angle of 0.01 radian draws a current of 0.5 A when supplied at 1000V from a sinusoidal voltage source. The active power consumed by the capacitor is-
The ratio of the reading of two-watt meters connected to measure active power in a balanced 3-phase load is 2: 1. The power factor of the load is -
A 40 KVA transformer has a core loss of 400W and full load copper loss of 800W. The fraction of rated load at maximum efficiency is-
Therefore fraction of rated load at maximum efficiency = 70.71%
A 4-pole, 1200 rpm DC lap wound generator has 1520 conductors. If the flux per pole is 0.01 weber, the emf of the generator is -
Three equal impedances are first connected in delta across a 3-phase balanced supply. If the same impedances are connected in star across the same supply
When three equal Impedances connected in delta across 3 – phase balanced supply, if they are connected in star power consumption will be 1/3rd of previous consumption.
If in an R-L-C series circuit the current lags the applied voltage by then-
Angle between V and I is
Power factor angle
As we know, for series R-L-C Circuit
A CRT with parallel deflection plate is 40 cm long and 10 mm apart have Ea=1000 V. Screen is 50 cm apart from center of parallel plates. Calculate the input voltage required to deflect the beam 5 cm.
Given, Ea=1000 V and Id=0.4 m, d=0.01 m, L=0.5 m and Ed=?
we know that,
If (Rg) in the circuit shown in the figure is variable between and
, then maximum power transferred to the load (Rl) will be-
(Rg) should be minimum to transfer maximum power to the load; therefore, we take
A 1 – phase energy meter does 100 revolution in 90 seconds. Meter constant for instrument is 1200 rev./KWh, then power consumed by load is –
We know that,
The controlling torque in gravity controlled meter is proportional to -
For gravity control
For spring control
A 0 – 200 V voltmeter has guaranteed accuracy of 2% at full scale. Find the % error if the measured value is 144 V
Maximum error = 2% of 240 = (200)×(2/100)= 4 V
% error when measured 100V = 4×(100/144)=2.78 %
Determine the value of shunt required to give multiplying power of 41 whereas the instrument resistance is 1600 Ω -
We know that,
Inductance of moving iron instrument is given as If the control spring torque is then find deflection in rad for a current of 3 A –
Deflecting torque of moving iron instrument is given as,
The impedance reflected back to the source in Fig. is………………..
An ideal transformer has N1 = 100 turns
N2 = 200 turns with a mutual flux of
ϕm (t) = -0.05(t2 - 2t). The induced emf of secondary in volts is
In a transformer maximum efficiency occurs at 80% of a full load then what is the Relation between ironless at rated voltage (Pi) and copper loss full load.
At maximum efficiency
Pc = Pi
Copper loss at 70% of full load
= (0.8)2 Pc
Iron loss at rated voltage = Pi
Pi = (0.8)2Pc
Pi=16/25Pe
25 Pi = 16 Pc
A current wave starts at zero, rises instantaneously, then remains at a value of 20 A for 10 sec, then decreases instantaneously, remaining at a value of -10A for 20 sec, and then repeats this cycle. The RMS value of the wave is.
The following is the apparent disadvantage of auto transformer as compared to two-winding transformer
Drawback of auto transformer
(1) If the transformer ratio K1 is far from unity, then the Auto transformer would not be economical one.
(2) The short circuit current in Auto transformer is higher than the short circuit current in two winding transformer.
(3) The main disadvantage of autotransformer is the direct electrical connection between low tension and high tension side, so it might be possible that the insulation of Cu may fail due to which a large current flow in windings.
The voltage wave given by v =4 cos produces a current wave i =1.5 cos in a circuit. The current wave-
A 250 V d.c. shunt motor takes a total current of 20 A. Resistance of shunt field winding is 200 Ω and that of armature is 0.3 Ω What is the current in the armature?
An electric load consumed 17.32 kW at a power factor of 0.707 (lagging). For changing the load power factor to 0.866 (lagging), the capacitor that is to be connected in parallel with the load should draw-
A 200/400 V, 20 kVA, 50 Hz single-phase transformer has, at full-load, a copper loss of 120 W. If it has an efficiency of 98% at full-load, determine the iron losses.
Transformer Efficiency η
η = 1 - (losses/input)
= 1- (Copper Loss + Iron Loss)/Input kVA
0.98 = 1- {( 120 + Pi)/(20x1000)}
0.98 x 20000 = 20000 - 120 -Pi
Pi = 20000 - 19600-120
= 280 W
In low oil circuit breaker, the oil performs the function of
In Low Oil Circuit Breaker the are extinction process is carried out in the upper chamber. So, it is called as an arc extinction chamber or current interruption chamber of Minimum Oil Circuit Breaker (MOCB).
A transistor is operating in common emitter mode, as shown in the figure given below. The voltage (VCE) is-
The transistor is operating in the active region. The initial assumption is valid.
Now, from collector to emitter loop,
The current I in the circuit shown is Figure is
Consider the following circuit.
What is the equivalent resistance between points A and B when VA < VB?
When VA < VB,the diode is reverse biased and can be replaced by an ‘open’. Therefore, RAB = 10 Ω
An over-excited 3-phase synchronous motor can be used to
An over-excited 3-phase synchronous motor is not only used as a motor to supply the needed mechanical power but also acts as a power factor correction device.But generally prefered for power factor correction.
A 18.65 kW, 220 V, 50 Hz, 4-pole, Y-connected synchronous motor is running with a light load. The load angle is 4o(elect.) and back e.m.f. generated per phase in 110 V. If the armature resistance per phase is 0.1Ω and synchronous reactance/ phase is 1.5Ω then resultant armature voltage/phase is ……………….
Which of the following expression is the mathematical representation of Mass Action law in electronics?
Mass action law states that at thermal equilibrium, the productof number of holes and number of electrons in a semiconductor are constant and is independent of donor and acceptor impurity doping (only intrinsic concentration is considered).
Semiconductor A has a higher band-gap than semiconductor B. If both A and B have the same electron and hole mobilities then
We have, intrinsic carrier concentration,
ηi∞e-Eg/2kT
And, hole concentration (by mass action law) is, p=ni2/n
⇒∞e-Eg/2kT
Thus, EgA>EgB
⇒pA < pB
Hence, hole concentration in semiconductor A is less than that of B.
The temperature coefficient of an intrinsic semiconductor is-
An ammeter is obtained by shunting a galvanometer with
resistance. What should an additional shunt be connected across it to double the range?
In the first case,
Now let R is connected across the ammeter.
Time constant of the network shown in the figure is-
Which of the following statement is correct?
Since copper is a metal, conductor, thus it has more number of free electrons in conduction band than that of silicon. Hence, fermi level of copper is at higher energy level than that of silicon.
In a transformer, the core loss is found to be 46W at 50 Hz and is 80 W at 70 Hz, both losses being measured at the same peak flux density. The hysteresis loss and eddy current loss at 60 Hz is-
The secondary load impedance of a step-up transformer is ZS The primary impedance ZP will be
In an Intrinsic semiconductor ________.
Semiconductors which are chemically pure, meaning free of impurities, are called Intrinsic Semiconductors or Un doped Semiconductor or i-type Semiconductor. The most common intrinsic semiconductors are Silicon (Si) and Germanium (Ge), which belong to Group IV of the periodic table. The atomic numbers of Si and Ge are 14 and 32.
A power insulator has 4 units. The voltage across the bottom-most unit is 33.33% of the total voltage. Its string efficiency is-
The string efficiency is given as
A transistor is a combination of two p-n junction with their
a transistor is a combination of two diodes, we have two junctions here. As one junction is between the emitter and base, that is called as Emitter-Base junction and likewise, the other is Collector-Base junction. A transistor is a combination of two p-n junction with their p region connected together and n region connected together.
The total line current drawn by the circuit shown in the figure is …………………
I = |IL+IR| = |V/jXL + V/R|
= |240/j30 + 240/30
= 8√2 A
A capacitor is charged by a battery. When the capacitor is having air core, the charge on the plates is 70 μC When the same capacitor has mica core of dielectric 7, the charge on the plates is
Variation in dc excitation of a synchronous motor causes variation in-
The open loop control system is one in which __________.
One type of control system in which the output has no influence or effect on the control action of the input signal is called an Open-loop system.
A 10 kVA, 2000/400 V single-phase transformer has a primary resistance and inductive reactance of 5 Ω and 12 Ω respectively. The secondary values are 0.2 Ω and 0.48 Ωrespectively. What is the impedance of the transformer referred to the secondary side?
The condition of a semiconductor diode can be determined quickly using:
On a digital display meter with a diode checking capability appears, the small diode symbol is the bottom option of the rotating dial to check the functionality of the diode. The curve tracer of can displays the characteristics of a host of devices, including the semiconductor diode.
By properly connecting the diode to the test panel at the bottom center of the unit and adjusting the controls, the display can be obtained.
Hence, the correct option is (C).
In a 50 kVA transformer, the iron loss is 500 W and full-load Cu loss in 800 W. The efficiency of the transformer at full-load at 0.8 p.f. lagging is
Full-load output
=kVA×cosϕ
=50×0.8
=40 kW
Total F.L. losses
=500+800
=1300 W
=1.3 kW
Full-load input
=40+1.3
=41.3 kW
Full-load
A circuit element that opposes the change in circuit voltage is
A capacitor opposes change in voltage while an inductor opposes change in current However, a resistor neither opposes change in voltage nor change in current.
A 100 kVA, 2200/440 V transformer has primary values R1=0.3 Ω, X1=1.1Ω and secondary values R2=0.01 Ω and X2=0.035 Ω The equivalent impedance of the transformer referred to the primary side is
The current in a 2.2 kΩ resistor is i(t)=5 sin(2π×100t+45∘)mA. What is the instantaneous value of resistor voltage at t = 0.4ms?
Vm = Im×R
= 5mA × 2.2kΩ = 11V
∴ v(t) =11 sin (2π×100t+45∘)V
At t = 0.4ms, v
= 11 sin[2π×100]
(0.4×10-3)+45∘]V
= 11sin (0.2513rad+45∘)
= 11(14.4∘ + 45∘)
= 9.47 V
The voltage across the open circuit is?
The voltage across all branches in a parallel circuit is the same as that of the source voltage.
So, the voltage across the 10-ohm resistor and the open circuit is the same=100V.
Hence, the correct option is (A).
The low voltage winding of a 300 kVA, 11000/2200 V, 50 Hz transformer has 190 turns and a resistance of 0.06 Ω The high voltage side has 910 turns and a resistance of 1.6 Ω. When low voltage winding is short-circuited, the full-load current is obtained with 550 V applied to h.b. side. What is the equivalent resistance referred to high voltage side?
If the discharge voltage of a thyite arrester is 373 kV RMS and the rated voltage is 211 kV RMS, the discharge factor of the arrester is -
What will the maximum power (in W) transferred from the source to the load of the circuit given below?
Vth = 40V
For maximum power transfer from source to load , load impedance must be
Zi=Z*th
ZL=10 - j20
Pmax=Vth2/4Rth
Pmax = 402/4x10 =40W
In a 3-phase induction motor, starting torque will be maximum when-
In a ____________ circuit, the total resistance is smaller than the smallest resistance in the circuit.
So, it is smaller than the smallest resistance in the circuit.
Hence, the correct option is (B).
Capacitor preferred when there is high frequency in the circuits is __________.
Mica capacitors are preferred for high-frequency circuits because they have low ohmic losses and less reactance.
Hence, the correct option is (B).
A wire has a resistance. It is stretched by one-tenth of its original length. Then its resistance will be-
From equation (3) and (4)
Two incandescent bulbs of rating 230 V, 100 W and 230 V. 500 W are connected parallel across the mains. As a result, what will happen?
A DC shunt generator builds upto 230 V. Other condition remaining the same; if only the residual magnetism of the original machine is reversed, the voltage to which the generator will build up is -
For the given V-I characteristic find out the value of dynamic resistance Rac?
Since the dynamic resistance is the reciprocal of line as-
The moderator used in a fast breeder reactor is-
A Zener diode has a Zener resistance of 4Ω if the current through it changes from 15 mA to 20 mA, the change of voltage across the Zener diode will be
ΔI = 5mA
ΔV = rz ΔI
= 4 × 5 × 10–3
= 0.02 V
Which one of the correct definition of work function
Work function is the minimum excess energy needed or required for thermionic emission and it is the emission of electrons form the heated of metals.
A 50 kVA, 500 V, single phase a.c. generator gave the following test results:
Open circuit test: A field current of 12 A produced an e.m.f. of 300 V.
Short circuit test: A field current of 12 A caused a current of 175 A to flow in the short-circuited armature.
The synchronous impedance of the generator is
Synchronous impedance,
Zs = 300/175 = 1.71 Ω
In a three phase system power measured by using two wattmeter method and total power measured by both wattmeter is 50kW and power factor is 0.5 lagging. Reading of second wattmeter is –
Total power,
P = 50kW
ϕ = 60 °
since at ϕ = 60 ° one watt meter reads 0 watts and entire power is reading by another watt meter
so at this condition the reading of another watt meter is zero.
Load factor for the load duration curve shown below is-
What will be the multiplying power of shunt of 400 Ω which is used with 800 Ω -
In reference to the figure, the voltage waveform v9t) is measured by a PMMC, a PMMC combined with bridge rectifier and a moving iron (MI) instrument. Two lists are prepared thereafter :
Instrument list List of instrument reading
List - II
a. PMMC
b. PMMC rectifier
c. M.I.
List - II
i. 5 V
ii. 2.75 V
iii. 2.5 V
The correct option relating the instruments and their reading is
PMMC reads average value.
Vavg = area/(time period)
From given waveform
Vavg = (10*4)/16 = 2.5 Volts
PMMC rectifier will read rms value = 2.75 Volts
MI reads true rms value
Vrms = (peak value)/2 (for square wave)
= 10/2 = 5V
Bucholtz relay cannot be used on-
A transformer is working at its full load, and its efficiency is also maximum. The iron loss is 1000 watts. Then, its copper loss at half of the full load will be-
The condition for maximum power output from dc motor is-
In two wattmeter method of measurement of three-phase power of a balanced load, if both the wattmeters indicate the same reading, then the power factor of the load is-
The Req for the circuit shown in figure is
Equivalent of 6 ohm 3 ohm in parallel = 6x3/9= 2 ohm
This 2 ohm again in series with 2 ohm resistor = 2+2 =4 ohm
Equivalent of 1 ohm & 5 ohm series = 1+5 = 6 ohm
Now 6 ohm & 4 ohm in parallel so its equivalent = 6x4/10 =2.4
Hence Req of the network = 4+2.4 +8 = 14.4
An AC voltage source with an internal impedance is connected to a load of impedance
. For maximum power transfer to the load, the condition is-
A 100 KVA single phase transformer exhibits maximum efficiency at 80% of full load, and the total loss in the transform under this condition is 1000 W. The ohmic losses at full load will be-
The voltage across a load is v(t) = 60(ωt-10∘)cos V and the current through the load in the direction of the voltage drop is i(t)=1.5cos(ωt+50∘)A The reactive power is
The r.m.s. values of voltage and current phasors are :
Vr.m.s.=60/√2∠-10∘V;
Ir.m.s.=1.5√2∠-50∘
∴ Complex power,
S = Vr.m.s.I*r.m.s.
=60√2∠-10∘×1.5/√2∠-50∘
Complex power,
S=45∠-60∘VA-(22.5-j38.97)VA.
Therefore, reactive power = 38.97 VAR, leading because reactive power is negative.
In Fig.,
Since the collector (p-type) is positive w.r.t. base (n-type), the collector is forward biased.
The total load taken from an a.c. supply consists of
A- a heating load of 15 kW
B- a motor load of 40 kVA at p.f. 0.6 lagging
C- a load of 20 kW at p.f. 0.8 lagging
A capacitor is connected in parallel with load and p.f. raised to unity. The kVAR rating of the capacitor should be