| Post Name | Materials Manager - Kerala State Co-Operative Coir Marketing Federation Ltd |
|---|---|
| Question Paper Code | 099/2025/OL |
| Category Code | 198/2024 |
| Date of Test | 27 August 2025 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
When a series RC circuit is connected to a dc voltage of V, the final steady-state current is
Answer
A. zero
2
What happens when a steady potential difference is applied across the ends of a conducting wire?
Answer
C. the random electron motion will, on average, be equivalent to a constant velocity of each electron
3
The self-inductance of a very long solenoid with a 2 × 2 cm cross section has an iron core is 8 H/m. The energy per meter stored in its field, if it carries a current of 500 mA, is
Answer
C. 1 J/m
4
A balanced Δ-connected circuit of Z_Δ Ω/phase is equivalent to a balanced Y-connected circuit of Z_Y Ω/phase if
Answer
A. Z_Y = (1/3)Z_Δ
5
In case of a series resonant circuit, a change in supply voltage will change
Answer
D. the current drawn
6
Assertion (A) : If the voltage across R, L, C elements connected in series in an ac circuit is 30 V, 10V and 50V respectively then the voltage applied will be 50 V Reason (R) : The applied voltage is equal to the maximum voltage existing across any of the three elements
Answer
C. A is true, R is false
7
A sinusoidal voltage is expressed as v = 20 sin(314t + π/6) V. Its frequency and phase angle are
Answer
C. 50 Hz, 30°
8
A 4 capacitor is connected in series with a 0.5 MΩ resistor across a 200 V dc supply. The initial charging current and time constant are
Answer
A. 400
9
Kirchhoff's laws can be applied to a network solution by
Answer
D. all the above
10
Match the following Column A Column B a. Thevenin's theorem I. A number of sources b. Norton's theorem II. An equivalent source of emf c. Superposition theorem III. An equivalent current source d. Maximum power transfer theorem IV. A circuit or source with low output impedance
Answer
B. a-II, b-III, c-I, d-IV
11
The EMF induced in a four pole DC generator having 1000 conductor lap-connected windings, the flux per pole of 10 mwb and rotated at 600 rpm is
Answer
D. 100 V
12
A four pole, 50 Hz, 400 V, three-phase induction motor is running at 1440 rpm. The frequency of rotor induced emf is
Answer
A. 2 Hz
13
Which of the following statement is not true for a synchronous motor?
Answer
B. An over-exited synchronous motor draws lagging power factor current
14
In alternator, damper windings are used to
Answer
C. prevent hunting
15
A transformer has hysteresis loss of 30 W at 240V, 60Hz. The hysteresis loss at 200 V, 50 Hz will be
Answer
B. 25 W
16
The iron loss in a 100 kVA transformer is 1 kW and full-load copper losses are 2 kW, then maximum efficiency occurs at a load of
Answer
B. 70.7 kVA
17
In a 3-phase induction motor, the starting torque will be maximum when
Answer
B. R₂=X₂
18
At nearly what percentage of full load is the distribution transformers designed to have maximum efficiency
Answer
B. 70
19
Synchronous capacitor is
Answer
C. an over excited synchronous motor without mechanical load
20
Induction motor, when directly switched on across their normal rated supply voltage, the torque developed at starting is about __________ of their full load torque
Answer
B. 1.5 to 2.5 times
21
An equilaterally spaced three phase transmission line has a corona loss of 2 KW/phase/KM at 60 Hz. The corona loss on the same system with supply frequency of 50 Hz will be
Answer
B. 1.8 KW/Phase/KM
22
In a 110 KV, three phase, 50 Hz power system the line to ground capacitance is 2 and the inductance is 4 H. In order to eliminate the transient critically the value of resistance the circuit breaker contacts required is
Answer
A. 707Ω
23
Assertion (A) : Differential protection can not be used for inter-turn faults. Reason (R) : In inter-turn fault currents at the two ends of the winding are not same.
Answer
C. A is true but R is false
24
Power station A has 2 identical generator sets each rated 50 MVA and having an inertia constant of 6 MJ/JVA whereas the station B has 3 generators rated 100 MVA and having inertia constant of 4 MJ/MVA. The inertia constant of a single equivalent machine on a base of 50 MVA will be
Answer
D. 36 MJ/MVA
25
The base KV and Base MVA of a three phase transmission line is 25 KV and 40 MVA respectively. The base current and base impedences are respectively
Answer
B. 923.8A, 15.6Ω/phase
26
A 50 Hz bar primary CT has a secondary with 450 turns. The secondary supplies 6A current into a purely resistive burden of 1.5Ω. The core flux in the CT under the given operating condition is
Answer
D. 90 μWb
27
The primary side of a 3 phase transformer is star connected with neutral grounded and secondary side is delta connected; its zero sequence network is
Answer
A. Bus 1 connected through Z₀ to a node shunted to the reference bus; Bus 2 is open (diagram in official source)
28
The boundary condition in double line to ground fault is
Answer
D. Ia=0, Vb=0, Vc=0
29
For the stable operation of a power system
Answer
C. The actual clearing angle is smaller than critical clearing angle
30
A string insulator has 4 units. The voltage across the unit near the powr conductor is 33.33% of the total voltage and the voltage across the unit nearest to the tower is 30.33% of total voltage. Its string efficiency is
Answer
B. 75%
31
An analog PMMC (0-10) A ammeter is provided with no controlling mechanism and the moving parts are free to rotate, the reading of the instrument if a current of 1 A DC passed through the moving coil
Answer
D. The pointer will continuously rotate
32
Energy meter is an example of __________ type of instruments
Answer
C. integrating
33
(0-1) mA ammeter has its internal resistance of 4 ohm. It's range is to be extended to 100A. The value of shunt resistance required is
Answer
A. 40 micro ohm
34
Which type of the instrument has the higher power consumption?
Answer
C. Hot wire
35
In an electrodynamometer, moving coil has an area A, turn N carries a current I producing a magnetic flux B. The torque on the moving coil is proportional to
Answer
B. I²
36
A wattmeter has a range of 1000 W with an error of ±1% of full scale deflection, if the true power passed it is 100 w, then relative error would be
Answer
A. ±10%
37
The brake magnet of an error free electromechanical induction type energy meter is shifted from its position and moved a small distances towards the edge of the disc. Then the meter will
Answer
B. Continue to work, but registers a lower kWhr
38
In two wattmeter method of power measurement, one of the wattmeter will show negative reading when load power factor angle is strictly
Answer
D. > 60 degree
39
Which of the following measuring devices has minimum loading effect on the quantity under measurement?
Answer
B. CRO
40
The sine wave output of a function generator is fed to both the horizontal (X) and vertical (Y) inputs of a CRO. What will be the pattern on the cathode ray screen?
Answer
C. A straight line with 45 degree slop
41
Which of the following statements are true? i. Transducers which require external power source for their operation are called passive transducers ii. Passive transducers produce an output signal in the form of variation of resistance, capacitance or any other electrical parameter and have high resolution. iii. Thermocouple is an example of active transducer
Answer
C. all are true
42
Which of the following statements about Hall effect transducer is correct? i. it can be used to measure power ii. it can be used to measure current in a conductor without physical connection between the conductor and meter iii. it is used to measure displacement of a structural element iv. it measures the magnetic field by converting it to a voltage
Answer
D. All are correct
43
An alkaline cell is discharged at a steady current of 5A for 10 hours, the average terminal voltage being 1.2 V. A steady current of 4A for 15 hours is required to bring it to original state of charge, the average terminal voltage being 1.44 V. The ampere-hour efficiency of the cell is
Answer
A. 83.33%
44
The watt-hour efficiency of the cell in the above question is
Answer
A. 69.44%
45
Which of the following statements are incorrect? i. Constant voltage charging allows the full current of the charger to flow into the battery until the power supply reaches its preset voltage with the current tapering to a minimum once that voltage level is reached ii. Current level is set at approximately 10% of the maximum battery rating in constant current charging iii. Constant voltage charging is comparatively fast and suitable for lead acid batteries. iv. Constant current charging is relatively slow with the disadvantage that battery may overheat if overcharged
Answer
D. none of the statements are incorrect
46
The system of earthing in which all parts are insulated from earth or one point is connected to earth through sufficiently high impedance is
Answer
D. IT system
47
The feature of TN-C system of earthing is that
Answer
A. functions of neutral and protective earth (PE) conductor are combined in a single conductor
48
The lamp for which efficacy is 135 lumens per watt for rating of 35 W and 183 lumens per watt for a rating of 180 W and has long and reliable life of about 18000 hours is
Answer
C. Low pressure sodium vapour lamp
49
The illuminance at a point 5 metres away from a point light source producing 3000 candela and with angle of incidence 30° with respect to the vertical is
Answer
C. 103.92 lux
50
The number of luminaries required for an illumination level of 300 lux in a room 6.5 m × 8m, considering coefficient of utilization 0.7365, light loss factor of 0.7, initial lamp lumens as 4000 is
Answer
C. 8
51
Which of the following represents a group incentive plan?
Answer
C. Scanlon plan
52
If the earliest start time for an activity is 8 weeks, the latest finish time is 37 weeks and the duration time of the activity is 11 weeks, then the total float is equal to
Answer
A. 18 weeks
53
One disadvantage of using North-West Corner Rule to find initial solution to the transportation problem is that
Answer
B. It does not take in to account cost of transportation
54
The dealer for washing machines forecasts the demand at the rate of 600 units per month, for the next four months. The actual demand is found to be 500, 680, 800 and 900 units. The mean absolute deviation (MAD) is found to be
Answer
A. 170
55
Ogive curves are
Answer
B. Cumulative frequency charts
56
Match List I with List II and select the correct answer using the codes given below the lists : List-I List-II a. Trend 1. R-Chart b. Dispersion 2. C-chart c. Number of defects 3. d. Number of defective 4. np-chart 5. u-chart
Answer
C. a-3, b-1, c-2, d-4
57
Which type of layout is preferred in order to avoid excessive multiplication of facilities
Answer
A. Process layout
58
In performing a task, motion economy refers to the manner in which
Answer
A. Human energy can be conserved
59
For a positively skewed distribution
Answer
B. Mean is greater than median
60
The following is the general policy for 'A' class items in ABC analysis : 1. Very strict control 2. Frequent review of their consumption 3. Safety stock kept Which of the above statements is/are correct?
Answer
D. 1, 2 and 3
61
Identify the wrong statement/s with respect to Schaeffler diagram for stainless steels. 1. High Ni equivalent stabilizes Ferrite 2. High Cr equivalent stabilizes Martensite
Answer
A. Both 1 and 2
62
The closest distance (centre-to-centre) between two atoms in a BCC crystal structure is ('a' is lattice parameter)
Answer
D. √3a/2
63
Excessive hardness after tempering operation may be observed due to
Answer
B. Low tempering temperature
64
Which of the following processes will NOT reduce the chance of hydrogen induced cracking?
Answer
C. High speed welding
65
In the Gas Tungsten Arc welding of thin Aluminium alloys (uncleaned), which of the following polarities are suitable? 1. Direct current straight polarity 2. Direct current reverse polarity 3. Alternating current
Answer
D. 2 and 3
66
Identify the correct statement/s 1. Compound rest method can only provide, small taper angles over short lengths 2. Tail stock set-over method can only provide, taper over complete span of the job
Answer
D. neither of 1 and 2
67
In grinding operation, loading occurs when
Answer
C. Metal particles clog space between abrasive particles
68
Match the machine parts with the movement direction generated, with reference to a column and knee type milling machine PART MOVEMENT 1. Table A. Parallel to spindle 2. Knee B. Up and Down (parallel to column) 3. Saddle C. Perpendicular to spindle and column
Answer
C. 1-C, 2-B, 3-A
69
Identify the correct statement/s 1. Reaming is an operation of enlarging a hole with a tool having only one cutting edge. 2. Trepanning is the process of making internal threads in an already existing hole
Answer
B. neither of 1 and 2
70
Identify wrong statement/s 1. A positive rake angle is preferred in case of interrupted cutting. 2. A negative rake angle provides increased cutting resistance.
Answer
C. only 1
71
Mercury is used in barometers because of which of the following properties i. Mercury has high density ii. Mercury has high vapour pressure iii. Mercury has low vapour pressure
Answer
B. i and iii are correct
72
In a shear stress vs velocity gradient graph, ideal fluid is represented by
Answer
C. The x axis
73
A peizometer is connected to a pipe containing water. Water rises to a height of 15 m in the piezometer. If the value of g is taken as 10 m/ , the value of absolute pressure of water in the pipe will approximately be
Answer
D. 2.5 bar
74
For a soap bubble of diameter D and surface tension, S, the excess pressure inside the bubble is given by
Answer
C. 8S/D
75
Which of the following statements are correct with respect to an air vessel fitted to a reciprocating pump? i. Water enters air vessel during second half of the suction stroke ii. Water enters air vessel during first half of the suction stroke iii. Water enters air vessel during first half of the delivery stroke
Answer
A. i and iii are correct
76
Which of the following statements are correct with respect to a draft tube fitted to a turbine i. Draft tube increases the net head but decreases the overall efficiency of the turbine ii. A draft tube creates vacuum pressure at the outlet of the runner iii. Cavitation occurs at the outlet of the draft tube
Answer
D. only (ii) is correct
77
A jet of velocity V is impinging on a series of vanes moving at speed u then the condition for maximum efficiency is
Answer
C. V = 2u
78
Which of the following statements are correct with respect to multistage centrifugal pumps? i. For producing high head a number of impellers are to be connected in series. ii For producing high head a number of impellers are to be connected in parallel. iii. If there are n impellers and head developed by each impeller is H. total head developed is given by n×H
Answer
A. (i) and (iii) are correct
79
On which of the following principles does a hydraulic ram work?
Answer
B. Water hammer
80
The percentage of work saved per stroke by fitting an air vessel in a single acting reciprocating pump is nearly
Answer
C. 85
81
A 1.2 m long column is fixed at both ends. It buckeles at 150 kN. What would be the buckling load if it were pinned at both ends?
Answer
A. 37.5 kN
82
A composite bar consists of a steel core of diameter d surrounded by a copper sleeve of inner diameter d and outer diameter 2d. The bar is subjected to an axial compressive force P. If the two materials are perfectly bonded and deform together, what is the ratio of load carried by copper to that carried by steel? (Given: E_s = 2E_c)
Answer
C. 3/2
83
A 1000 N block is placed on a 30º inclined rough surface with coefficient of friction μ=0.3. What is the friction force acting on the block?
Answer
B. 260 N, up the incline
84
In a lap joint with 2 rivets in double shear, if shear strength of rivet is 250 MPa and rivet diameter is 16 mm, what is total shear strength?
Answer
D. 201 kN
85
A fillet weld is subjected to an external force of 60 kN, applied at an eccentricity of 100 mm from the weld group centroid. The total throat area of the weld is 800 . Assume the weld group is symmetric and the maximum distance from centroid to any weld element is 100 mm. If the polar moment of the throat area about the centroid is approximately , what is the maximum resultant shear stress in the weld?
Answer
B. 106 MPa
86
The shear stress in a square thread of mean diameter equal to 30 mm and pitch equal to 6 mm under 12 kN axial load is (Assume only one thread is engaged in carrying the load)
Answer
C. 42.5 MPa
87
A shaft is manufactured to an H7/f8 fit. If the shaft size increases within its tolerance, what is the most likely effect on the clearance or interference between the shaft and hole
Answer
B. Clearance decreases and may lead to interference
88
In a cam-follower mechanism with a roller follower, which of the following factors primarily determine the variation of pressure angle during the cam rotation
Answer
B. Cam displacement law, base circle radius, roller radius and can rotation angle
89
In a hydrodynamic journal bearing, which of the following statements is correct when the Sommerfeld number is decreased, assuming all geometric parameters (radius, clearance, length) remain unchanged?
Answer
C. The eccentricity ratio increases, leading to a thinner minimum film thickness
90
In an epicyclic gear train, the sun gear has 30 teeth, planet gear 20 teech and ring gear 70 teeth. If the arm is fixed and the sun rotates at 100 rpm clockwise, what is the speed of the ring gear?
Answer
C. 43 rpm (anticlockwise)
91
The efficiency of a ideal Diesel cycle
Answer
C. Depends on both compression ratio and cut off ratio
92
A very low value of Prandtl number indicates
Answer
A. A dominance in heat transfer by conduction
93
Work done on air is minimum in which of the following compression processes?
Answer
B. Isothermal
94
The COP of Reverse Carnot System (RCS) is greater than Vapour Compression Refrigeration System (VCRS) because i. The refrigeration effect in VCRS is reduced due to throttling ii. The compression work required in VCRS is more than RCS iii. Heat rejected by VCRS is more than RCS
Answer
A. i and ii are correct
95
Dew point temperature is the temperature at which condensation starts when air is cooled at constant
Answer
C. Pressure
96
The equivalence ratio of mixture entering the spark ignition will be
Answer
B. Greater than 1 for both idling and maximum power conditions
97
The work output of a heat engine operating in Carnot cycle is one fourth of the heat transferred to the sink. The efficiency of the engine will be
Answer
C. 0.2
98
Which refrigerants given below has lowest Ozone Depletion Potential
Answer
D. R-22
99
The maximum possible effectiveness of a parallel flow heat exchanger is around
Answer
D. 50%
100
In axial flow compressors, stalling of blades is related to
Answer
C. Air stream not following blade contours
Discussion
Ask a doubt or share a tip.
No comments yet — start the discussion.