HAL Entrance Exam Question Papers

I am looking for previous year’s question papers of HAL entrance exam for preparation so please provide me the same?

[Raman Vij]

Here I am providing you previous year’s question papers of HAL entrance exam for preparation.

1) Self GMD is used in the calculation of_______
a) inductance only
b) inductance and capacitance
c) capacitance only
d) none

2) What is the GMD if the distance between the lines are 6m,6m,12m?
ans: 7.058m( approx)

3) Zero sequence currents doesn't exist in the following fault
a) L-G
b) L-L
c) L-L-G
d) L-L-L-G
Ans: d

4) To avoid arcing connect sutable value of ________ in earthing.
a) capacitance
b) indunctance
c) resistance
d) susceptance

5)There are two to three questions based on Laplace and Inverse Laplace transforms

6)In the following type of conductors the corona is minimum
a) circular
b) stranded
c) helical
d) rectamgular
ans: c

7)When do two wattmeters show same value of opposite readings in two wattmeter method
a) 300 lag
b) 600 lag
c) between 600 and 900 lag
d) zpf lag
ans: d

8) Schering bridge is used to measure
a) frequency
b) inductance
c) capacitance
d) mutual inductance
and: c

9) What is the value of resistance when both length and diameter of the wire are doubled?
ans: halved

10) There is one questions asked on euler's formula.

11) What is the Laplace transform of unit ramp signal?
ans:1/s2

12) What is the largest rating of alternator manufactured in india?
a) 1000MW
b) 500MW
c) 1200MW
d) 250MW
ans:b

13) The response of an RLC circuit for impuse input?
a) exponentially raising
b) sinusoidal
c) exponential falling
d) parabolic
ans: c

14) What is the easier method for finding no. of poles in the right half of s-plane?
a) Niquist plot
b) R-H criterion
c) Root-Locus method
d) Polor plot
ans: b

15) How many no of poles located in the right half of s-plane for the characteristic equation?

16) Burden of current transformers is measured in..
a) Watts
b) Volt Amperes
c) Ampere Hours
d) Joules

17)What is the gate used to get high output when all the inputs are low?
a) NOR
b) NAND
c) Ex-OR
d) Ex-NOR
ans: b

18) What is the line current of a circuit when the current transformer of 1000:5 rating measures 4Amperes?
ans: 800A

19) If the time delay of relay with TMS setting 0.1 is 10 sec, then what is the time delaty when the TMS setting is changed to 0.5?

20) In distribution lines_____
a) X/R<0.1
b) X/R>10
c) X/R>1
d) X/R<0.01


Detailed Previous Year’s Question Papers of HAL Entrance Exam:

HAL Entrance Exam Paper 1

1.The Kaziranga national park in Assam is famous for ----------------
A) one horn rhinoceros B)white tiger C)Impale D)none of these ans a
2.The old name of Delhi was ----------------
a) Indrastuptha b)gaya c) pataliputra d) ayodhya
3. All the electioneering campaign has to end --------------
a) before 48 hrs of polling b) before 48 hrs of commencement of results c) before 36 hrs of polling
d) before 72 hrs of polling
4. In 1590 , when Portuguese first visited the island Taiwan they named it as
a) Taliban b)mayanmar c) forusa(spelling missing ) d) none of these
5.According to Indian mythology Ravana was well skilled in playing --------
a) sitar b)sarood c)Harmonium d) fluete
6.which of the following is not a beach in Goa --------------- no idea about options
7.which hindi (b/w) film was first converted to color---------------
a) Moghal E Azam b) Alam Ara c) Satya Harishchandra d) none
8.Which of the following book is not written by Charles Drekens …………………. no idea about
options English related ……………….
9.Escape : Abscond :---------------------------
10.inception : Conclusion :---------------------------
11. the appropriate meaning of Ocular in the following is --------------------
12.Which hand you use to write-----------? A)about b) on c) in d) with
13. He is in the habit --------------(find ) new things a) in finding b) of finding c) with finding d)to
finding
14.Phoebe was in the car when her phone is ringing ------------------ rewrite the sentence without
changing the meaning
15. She was in the kitchen when the telephone was ringing ---------------- rewrite the sentence
16. All his friends are older -----------him a)to b)than c)for d)from
17. you ------------be careful when you want not to be blamed a)have to b) has to c) had to d) none of
these
Section two……………… mental ability and Quant ……..
18. what is the next number in the series . 4, -8,16,-32,64,
a)192 b) 256 c)-128 d)128 ans c
19. odd men out …. 3,5,7,11,12,13,17,19
a) 3 b) 7 c)12 d)19 ans c
20.in the following series which is not correctly fit 7,8,18,57,228,1165,6996
a)7 b)57 c)228 d) none of these ans c
21. odd men out 583, 462, 792,427,132
a) 462 b)427 c) 132 d) 792 ans b
22. if x>y and x2-2xy + y2 -9=0, x +y = 15 …what is the value of x
a)3 b)12 c)10 d)9 ans d
23. how many times in day the hands of a clock are straight
a) 48 b)44 c)22 d) 24 ans b
24.which of the following numbers is divisible by 3,7,9 and 11
a)2079 b) 1266 c)1165 d) none of these ans a
25.Odd men out sitar, veena, tumpura ,sarood
26. Odd men out cricket, boxing, golf, tennis, hockey, football, bowling
a) cricket b)bowling c) golf d) boxing
Three Questions were given on figures like what is the next figure in sequence
Section three ……..Technical Related to digital electronics
27.the radix or base of hexadecimal number system is -----------a) 8 b)16 c)5 d)none of these
28.the no of 1’s in the binary representation of the expression 162*9+162*7+16*5+3 are ………….
a)10 b)23 c)6 d)4
29. the no of latches in F/F are -------
a)1 b) 2 c) 3 d)4
30.how many flip-flops are required to construct Mod -12 counter
a)5 b)4 c)12 d)none
31. which logic gate has the output is compliment of its input ----------
a) OR b) AND c)NOT d) X-OR
32.no.of 2-input multiplexers needed to construct a 210 input multiplexer…….
a) 12 b)31 c)20 d)16
33.By adding inverters to the inputs and output of a AND gate we can obtain ……………
a ) OR b) AND c)NOT d) X-OR
34.how many NAND gates are needed to realize OR gate --------------
a)1 b) 2 c) 3 d)4
35.which is the first integrated logic family ---------------
a) RTL b)DTL c)TTL d) none of these
36.The advantage of CMOS over TTL are---------------
37.the range of allowable voltages for CMOS are----------------
38.the voltages required to 0 and 1 in TTL family are -----------------
39. Which logic gate has output high if and only if all inputs are low ---------?
a) NOR b)NAND c) X-NOR d)AND
40.According to Boolean algebra 1+A+B+C =
a) A b) A+B+C c)1 d) none of these
41. If a=0x6db7 and b=0x2ae9 then what is the value of a”b--------------
Questions related to C ……
42.which of the following is not a primitive type in C
a)Int b)Float c) Char d) noneof these
43.If you want to accept variable no of arguments then you have to include which of the following
header files
a) Vararg.h b) stdarg.h c) stdlib.h d) stdioh
44. Register variables are stored in ----------------
a) CPU b) main memory c) secondary memory d) peripheral memory
45.what are pointers , when declared , initialized to --------
a) Garbage b)NULL c)0 d) nothing
46.When you divide a program into functions-----------------
a) it is easy to conceptualize and runs faster than usual
b) it is easy to conceptualize
c) it runs faster than actual one
d) none
47. In order to use a pointer it has to be ----------------
a) declared b) declared and initialized c) no need of declaration d) initialized
48.what is the output of the following program snippet
Int a=6,b=4; Pirntf(“%d”, a==b); a) Prints 6 b)prints 0 c)Prints 1 d) prints 6 4
49.what is the output of following code segment Char wer[3][4] = { ‘per’,’max,’min’}; Char ( *ptr)
[4]=wer; Printf(“%d%d”,ptr,ptr++);
a)262 262 b)262 263 c)262 265 d0262 266
50.if we give 12345 through scanf what are the values stored at a,b,c Int a,b,c; Scanf(“%d%d%d”,
&a,&b,&c);
a)a=12, b=34,c=5 b)a=12345 and nothing at b,c c)c=12345 and nothing at a,b d)an error message
51.what is the value stored in S Char s[4]; Scanf(“%s”, ‘1234’);
a)1234 b) 1 c) garbze d) error
52.what is the output if we give abc through scanf Char x,y,z; Printf(“%d”,scanf(“%c%c%c”,
&x,&y,&z));
a) prints 3 b) prints 1 c) error message d) prints nothing
53. A variable declared as “ unsigned U” then u is interpreted as
a) unsigned char b) unsigned int c) unsigned float d) the declaration is not possible
54.char c;Printf(“%d”, c); prints ----------------
A negative integer b)always positive integer c) garbage d)none
97.What is the output of the following program
Int a=1;
Printf(“%d”,(a++));
a)1 b)2 c)error message d) none
98.which of the following is incorrect about ++ operator
It is a unary operator b) it can be used in expressions c) left as well as right associative d) can be
overloaded
Questions related to TOC and LP
55.Two languages S and T represented by the regular expressions s=(a+b*) T=(a+b)* then the
relation between them is a)s
56.The language L={an bn cn /n=1,2,3,4………} is
a) not context free language but its complement is I CF
b) a context free language
c) a context free language and accepted by Push Down Automata
d) a context sensitive language
57.Finite State Automation -----------------device
a) repeater b) acceptor c) divider d) adder
58.The language L={anbn /n=1,2,3,4…………} can be generated from
a) S? ab/aSb/€
b) S? aaSbb/ab
c)S? abb/aSb
d) ab/aSb
58.The regular expression (a/b) generates the set
a) {a} b) {b} c{a,b} d) none
59.The regular expression (a/b)* represents
a) all combinations of a or b and same as (a*b*)*
b) all combinations of a or b and not same as (a*b*)*
c) all combinations of a and b , same as (a*b*)*
d) all combinations of a and b not same as (a*b*)*
60.Context sensitive Languages are ---------
a) super set of context free languages and accepted by Push Down Automata
b) super set of context free languages and accepted by non deterministic PDA
c) Accepted by Turing machines only d) none of the above statements are correct
61.Any context free Grammar can be converted into
a) Chomsky Normal Form b) GreiBack Normal form c) CNF and GBNF d) none
62. If a grammar is left-recursive and right-recursive to a non-terminal symbol then the grammar is
a) Ambiguous b) Unambiguous c) the information provided is not sufficient to determine d) none
63.FSA can be used to add two Integers -------------
a)TRUE b) may be TRUE c)FALSE d ) may be FALSE
64.context sensitive languages are -----------
a) accepted by push down automata b) accepted by non-deterministic pushdown automata
c) accepted by 2- way linear bounded automata d) a& c
65.The difference between the Moor and Mealay machines is
a) the former one depends on the present state and present inputs
b) the former one depends on the present state only
c) the later depends on the present state and present inputs
d) the later depends on the present input only
66 An FSA can be stated as -----------
A Turing machine with finite tape, unidirectional moment
A Turing machine with finite tape and bidirectional moment
A Turing machine with finite tape , unidirectional and no repetitions
A Turing machine with infinite tape , unidirectional and no repetitions
67.Recursive Languages are ------------
a) super set of all languages
b) type -8 grammar languages
c) accepted by Turing machine
d) we cant say anything about acceptance
68.which of the following statement is wrong about regular expressions
a) there exists a FSM to accept regular expression
b) there exists a N-FSM to accept regular expression
c) there are no ? symbols in regular expression
d) none
69. Regular expression cannot be used in which of the following
a) construction of text editors
b) design of serial circuits
c) design of compilers
d) finding text patterns
Questions related to hardware and OS
70.the term “memory” is related to
a) input and output b) storage c) ALU d) none
71. which of the following is not a Operating system
a)AIX b)PROLOG c) WINDOWS d) UNIX
72.The CPU or MPU consists of
a) input and output b) memory c) ALU d) All of the above
73. In a multiprogramming system
a) there are more than one processor
b) program are executed faster than actual
c) used in case of large programs only
d) more programs executed than actual in given time
74.the front side bus (FSB) also called as
a) control bus b) the processor bus c) PCI bus and processor bus d) none
75.which language is used Artificial Intelligence SYSTEMS
a) Java b) c# c) prolog d) Lisp
76.what is the capacity of Hollerith card when it is in extended state
a) 32kb b) 120 kb c) 240 kb d) 20 kb
77.how many slots are there for UTM device
a)1 b) 2 c) 3 d) 4
78.which part of the computer has the capability to acces memory and manipulate the memory
contents a) input/output b) cpu d) ALU d) none
79. the register which is used to locate the address of the operands and restore the contents is
a) memory address register b) memory data register c) instruction register d) none
80.the opcode --------------
a) tells the address of operands b) instructs the processor c) stores the values d) specifies the operation
81.the language first executed by microprocessor is
a) BASIC b) FORTRAN c) PASCAL d) MODULA
82. which language most suitable for mathematical calculations
a) FORTRAN b) PASCAL c ) C++ d) NONE
Questions related to C++ and OOPs they asked around 20 qs on this (5+ related to friend function)
83.the protected members are -------------
a) accessible within the class only b) accessible within the class and derived class c)cannot be accessed
outside the class d)can be accessed anywhere
84.By default the access specifier is -------------- a)private b)public c)protected d)none
85. A class is a -----------------
a) a abstract data type b) way of encapsulating data and code c) structure d)………….
86.which function can access the private members of a class ------------
a) any function b) member function of derived class c) friend function of that class d) friend function
of derived class
87.In order to access the private members of four classes that function has to be declared as friend of
-----------------------
a) any one class b) all four classes c)any three classes d) any two classes
88.when a class is derived from another derived class then that inheritance is called ----------
a) multiple b) multipath c) hybrid d) multilevel
89.which of the following are correct about A static member function
a) it has only one copy for all instances and it can access constant variables
b) it has separate copy for each instances
c) it cannot operate on constant variable
d)……………………………..
90.you are hiding the data when you are writing
a) a class b) cryptic code c) static function d) ADT
91. In order to declare a member function of one class as a friend of another class we need to use
a) the key word Friend b) the key word friend and scope resolution c) only scope resolution d) nothing
Question s from Discrete mathematics (only 2)
92. there are 100 nodes in a graph . if two nodes i ,j are said to be adjacent then |i-j|=12 or 8.
How many connected components in the above graph a)4 b) 8 c) 12 d) 25
93.in case of a binary tree all parent nodes are having degree 2 and in the child level the child are
associated to left . what is the name of the tree a) full binary tree b) complete binary tree c) threaded
binary tree d) none
DAA
94.what is the worst case complexity of bubble sort
a) O(n) b) O(logn) c) O(nlogn) d) O(n2)
95.which of the following sorting technique performs well when the element are in reverse order
a) bubble sort b) insertion sort b) mergesort d) heap sort
96.in which type of searching we can search the element in O(1) time averagely
a) linear search b) radix search c) hash based search d) binary search

HAL Entrance Exam Paper 2

1) the purpose of feedback transformer & diode in complementary commutated inverters is to-
2) in order to obtain static voltage equalization in series connected SCR’s connection r made of-
(this question repeated) (i.e. 2 times same question Haaa)
3) in phase controlled rectification PF=
4) Why sector winding is used in synchronous motor?
5) A calculation of making current where MVA & KV was given.
6) The o?p voltage e1 & e2 of 2 full-bridge inverters added using o/p transformer. In order to
eliminate 5th harmonic from o/p voltage, the phase angle between e1&e2 will be-
7) A single phase fully controlled line commutated ac-dc converter operates as an inverter when-
8) An SCR has half cycle surge current rating of 3000A for 50Hz. One cycle surge current will be.
(double of that)
9) When compared to an symmetrical thyristor, the turn off time & reverse blocking voltage of an
asymmetrical thyristor will be-
10) A step-up chopper is feed from an 220v dc source to deliver a load voltage of 66o v. If the non
conducting time is 100micro-sec then reqd pulse width will be. (get duty cycle only)
11) There were some 5-6 numerical problems which I could not remember totally but they consist of
firing angle & power transfer of inverter, SCR. Go llok for that.
12) Relay current setting & Ct ratio was given you have to find out Relay Pick up Current.
13) One question from Dc shunt motor- like a resistance is added of 4.5 ohm in series with arm where
rest of arm is 0.5 ohm. Machine is supplied 220v. find out the null current.
14) In aptitude part see through series completion there was a 5-6 no of that.
15) No aptitude questing like avg, %, proff-loss, prob, etc.
17) Why rotor of SCIM is skewed?
19) Good transformer oil contains how much amount of water in ppm?
20) Lightning over voltage create how much volt?
21) K/s(s+1)(s+5) then find out the value of K so that system become stable.
22) There was a question from definition of Nyquist criteria.
23) Standing done up to the frequency range of? (audio)
24) If a square waveform if given to the supply side of a 2wdg transformer its o/p waveform will be-
25) SC test done on transformer because....
26) If a transformer is operating in .8 PF lag & at efficiency of .9, if now P is .8 lead the efficiency
will become.
27) Interpoles are connected for?
28) Dielectric strength of air?
29) A alternator is connected to a grid. Now its prime mover is go slow by ½. Change in its exiting
current to held in synchronism.
30) Is the strength of capacitor in LPF is increased the op voltage will-
31) The voltage of a generator and an infinite bus are given 0.92, 10 deg & 1.0, 0 deg resp. the
generator acts as a –
32) A wave will not experience any reflection when impedance of line is equal to- surge imp
33) Power transmitted is related to system voltage as-
34) Delay creator ckt name (multivibrator name actually)
35) In tachogenerator adjustment is done by-
36) Surge wave is attended by- (C,L,R)
37) there was 10 question related to measurement-
38) Read all electrostatic instrument related question from any competitive exam book.
39) Lowest reading in moving iron meter is-
40) In galvanometer damping is provided by-
41) In electrodynamic meter a battery & a resistance is provide for-
42) Megger is used for-
43) A question like an ac is applied against a moving coil meter it will reads-
44) Rectifier type instrument measureswhat value - (Rms)
45) Advantage of electrostatic instrument is-
46) Creeping occurs because-
47) Why 2 holes are drilled oppositely in disc of energy meter.
48) Energy meter is a _____ type equipment (recording)
49) There was a question related to selection of a voltmeter based on accuracy-
50) Advantage of hay bridge over anderson bridge-
51) Inductance is measured by – (all the 3 bridge name) .
52) Potentiometer is which type of instrument-
53) Which type of motor is used in refrigerator?
54) Reflection coefficient based problem 1
55) Corona’s advantage


HAL Entrance Exam Paper 3

1. When length of a wire increases its resistance
a. doubles b. half c. remains same
Ans: ( a )
2. When a 50 Hz ,6-pole Induction Motor runs at 975rpm,the rotor emf frequency is
a. 12.5Hz b. 1.25Hz c. 4Hz
Ans: ( b )
3. When a 6 pole 50Hz Induction Motor runs at 1450 rpm , it’s working mode is
a. motoring b. braking c. generating
Ans: ( a )
4. Slips for Different modes of operation of Induction Motor are
answer: motoring -0<S<1,generating- S<0,braking - S>1
5. Damping ratio ( ξ ) is 0.75, natural frequency is 12 rad/s are given & asked to find peak time
6. In electrodynamo-meter type wattmeter
a. pressure coil is made fixed
b. current coil is made fixed
c. both the coils are made fixed
Ans: ( a )
7. In flux meter control torque is produced by
a. weights attached to it.
b. Springs
c. No control torque is there
Ans: ( c )
8. One question regarding hot wire instrument
9. In MI meters deflecting torque is proportional to
a. square of the current
b. square of the voltage
Ans: ( a )
10.In 3-Φ system total power is given by
a. √3VLILcos Φ
b. 3VLILcos Φ
c. VLILcos Φ
Ans: ( a )
11.From supply one 3-Φ step-down transformer is drawing 10 A, the secondary current will be
minimum when the transformer is
a. star-delta
b. delta-star
c. delta-delta
d. star-star
Ans: ( b )
12.Transformer rating is expressed in
a. KVA
b. KVAR
c. KW
Ans: ( a )
13.Manganin is a
a. Insulator
b. Semi-conductor
c. Alloy
14.Dual scope oscilloscope has
a. two separate horizontal and two separate vertical plates
b. one horizontal and two separate vertical plates
c. two separate horizontal and one vertical plates
d. one horizontal and one vertical plates
15.Standard Cell voltage is measured by
a. MI meter
b. MC meter
c. Potentiometer
16.The input resistance of the CRO is of the order of
a. tens of ohm
b. mega ohm
c. kilo ohm
d. fraction of an ohm
Ans: ( b )
17.Errors are introduced in Wheatstone bridge due to
a. lead resistance
b. contact resistance
c. some thing is given
d. all of the above
18.HRC fuse and circuit-breaker combination is used CB operates for
a. low over-load currents
b. high over-load currents
c. combination is never used
19.G(s) = K / s(s+5)(s+1) is given to find the value of K for stable operation
20.By increasing gain of the system root locus will
a. moves away from poles
b. moves away from zeros
c. crosses imaginary axis
Ans: ( a )
21.When the load current is high while measuring power using wattmeter
a. current coil is connected near load
b. pressure coil is connected near load
22.C = 0.01µF and L = 1 mH and current is 10 A and asked to find the voltage drop
23.Transmission line is terminated by R and no reflection is there , then the value of R is
_________
Ans: 400 ohm
24.One question regarding shunt ohm-meter and seriea ohm-meter
25.Inverted V curves are drawn between ________
Ans: field current Vs power factor