Explore topic-wise MCQs in Testing Subject.

This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.

1.

The design of electromagnets is based upon which of the following fundamental equations ?

A. Force equation
B. Magnetic circuit equation
C. Heating equation
D. Voltage equation
E. All of the above
Answer» F.
2.

D.C. windings are

A. sometimes 2-layer type
B. never 2-layer type
C. always 2-layer type
D. none of the above
Answer» D. none of the above
3.

E.m.f. of a Weston cell is accurately measured by

A. electrostatic voltmeter
B. hot wire voltmeter
C. isothermal voltmeter
D. electrodynamic voltmeter
Answer» B. hot wire voltmeter
4.

In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was

A. unity
B. 0.8 lagging
C. 0.8 leading
D. zero
Answer» B. 0.8 lagging
5.

The distance between the starts of two consecutive coils measured in terms of coil sides is called

A. front pitch
B. winding pitch
C. commutator pitch
D. back pitch
Answer» C. commutator pitch
6.

The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following?

A. Corrugations
B. Fins
C. Tubes
D. All of the above
Answer» E.
7.

The switch board instruments

A. should be mounted in vertical position
B. should be mounted in horizontal position
C. either (A) or (B)
D. neither (A) nor (B)
Answer» B. should be mounted in horizontal position
8.

On which of the following variables heat convected depends ?

A. Power density
B. Temperature difference between heated surface and coolant
C. Thermal resistivity, density, specific heat
D. Gravitational constant
E. All of the above
Answer» F.
9.

In direct cooled system using hydrogen both stator and rotor conductors are made

A. solid
B. hollow
C. perforated
D. any ofthe above
Answer» C. perforated
10.

By which of the following methods motor rating for variable load drives can be determined ?

A. Method of average losses
B. Equivalent current method
C. Equivalent torque method
D. Equivalent power method
E. All of the above
Answer» F.
11.

_________ electromagnets generally function as holding magnets.

A. Tractive
B. Portative
C. Either of the above
D. None of the above
Answer» C. Either of the above
12.

D.C. machines designed with a large value of air gap length have

A. worst, ventilation
B. poor ventilation
C. better ventilation
D. none of the above
Answer» D. none of the above
13.

When a bolt is subjected to shock loading, the resilience of the bolt should be considered in order to prevent breakage at

A. shank
B. head
C. in the middle
D. at the thread
Answer» E.
14.

If an application calls for stresses on screw threads in one direction only, then the following type of thread would be best suited

A. square
B. acme
C. buttress
D. BSW
Answer» D. BSW
15.

The connecting rod bolts are tightened up with initial tension greater than the external load so that

A. joint may not open up
B. bolts are weakest elements
C. the resultant load on the bolt would not be affected by the external cyclic load
D. bolts will not loosen during service
Answer» D. bolts will not loosen during service
16.

Allen bolts are

A. self locking bolts
B. designed for shock load
C. used in aircraft application
D. provided with hexagonal depression in head
Answer» E.
17.

For standard coarse threads of nut, the threads will be as strong in failure by shear as the bolt in tension, if the height of nut (h) is approximately

A. 0.4 times
B. 0.6 times
C. 0.7 times
D. 0.8 times
Answer» B. 0.6 times
18.

I.S. specifies following total number of grades of tolerances

A. 18
B. 16
C. 20
D. 22
Answer» B. 16
19.

If shearing stress in nut is half the tensile stress in a bolt, then nut length should be equal to

A. diameter of bolt
B. 0.75 x diameter of bolt
C. 1.25 x diameter of bolt
D. 1.5 x diameter of bolt
Answer» B. 0.75 x diameter of bolt
20.

Whether any core is required in wire ropes

A. yes
B. no
C. sometimes
D. rarely
Answer» B. no
21.

In cross or regular lay ropes

A. direction of twist of wires in strands is opposite to the direction of twist of strands
B. direction of twist of wires and strands are same
C. all of the above
D. none of the above
Answer» B. direction of twist of wires and strands are same
22.

Three different weights fall from a certain height under vacuum. They will take

A. same time to reach earth
B. times proportional to weight to reach earth
C. times inversely proportional to weight to reach earth
D. unpredictable
Answer» B. times proportional to weight to reach earth
23.

In V-belt drive, belt touches

A. at bottom
B. at sides only
C. both at bottom and sides
D. could touch anywhere
Answer» C. both at bottom and sides
24.

Oil in journal bearing should be applied at the point where load is

A. nil or lightest
B. maximum
C. average
D. all of the above
Answer» B. maximum
25.

In hydrostatic bearings

A. the Oil film pressure is generated only by the rotation of the journal
B. the oil film is maintained by supplying oil under pressure
C. do not require external supply of lubricant
D. grease is used for lubrication
Answer» C. do not require external supply of lubricant
26.

The usual clearance provided in hydrodynamic bearing per mm of diameter of shaft is

A. 0.01 micron
B. 0.1 micron
C. 1 micron
D. 10 microns
Answer» D. 10 microns
27.

In hydrodynamic bearings

A. the oil film pressure is generated only by the rotation of the journal
B. the oil film is maintained by supplying oil under pressure
C. do not require external supply of lubricant
D. grease is used for lubrication
Answer» B. the oil film is maintained by supplying oil under pressure
28.

If two springs are in parallel then their overall stiffness will be

A. half
B. same
C. double
D. unpredictable
Answer» D. unpredictable
29.

Aircraft body is usually fabricated by

A. welding
B. precasting
C. rivetting
D. casting
Answer» D. casting
30.

When a close coiled helical spring is compressed, its wire is subjected to

A. tension
B. shear
C. compression
D. all of the above
Answer» B. shear
31.

When two springs are in series (having stiffness K), the equivalent stiffness will be

A. K
B. K/2
C. 2K
D. KIA
Answer» C. 2K
32.

Spring stiffness is

A. ratio of coil diameter to wire diameter
B. load required to produce unit deflection
C. its capability of storing energy
D. its ability to absorb shocks
Answer» C. its capability of storing energy
33.

Spring index is

A. ratio of coil diameter to wire diameter
B. load required to produce unit deflection
C. its capability of storing energy
D. indication of quality of spring
Answer» B. load required to produce unit deflection
34.

Which of the following pipe joints would be suitable for pipes carrying steam

A. flanged
B. threaded
C. bell and spigot
D. expansion
Answer» E.
35.

The piston rod of a steam engine is usually connected to the crosshead by means of

A. bolted joint
B. kunckle joint
C. cotter joint
D. universal joint
Answer» D. universal joint
36.

When a nut is tightened by plaping a washer below it, the bolt will be subjected to following type of loads

A. compression
B. tension
C. shear
D. combined loads
Answer» C. shear
37.

Castle nut is a locking device in which

A. one smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
B. a slot is cut partly is middle of nut and then slot reduced by tightening a screw
C. a hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
D. through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end
Answer» E.
38.

The strap end of a connecting rod of steam engine is joined by

A. gib of cotter joint
B. sleeve and cotter joint
C. spigot socket cotter joint
D. knuckle joint
Answer» B. sleeve and cotter joint
39.

A tube has the following advantage over pipe

A. lighter and easier to handle
B. greater shock absorption
C. smoother inside walls
D. all of the above
Answer» E.
40.

In order to permit the thermal expansion/contraction of tubing, it should be

A. crimped
B. honed
C. flared
D. bent
Answer» E.
41.

The function of cutting oil when threading a pipe is to

A. provide cooling action
B. lubricate the dies
C. help remove chips
D. all of the above
Answer» E.
42.

Taper on the cotter and slot is provided

A. on both the sides
B. on one side only
C. on none of the sides
D. may be provided anywhere
Answer» C. on none of the sides
43.

A bench vice has following type of threads

A. metric
B. square
C. buttress
D. acme
Answer» E.
44.

The draw of cotter need not exceed

A. 3 mm
B. 5 mm
C. 10 mm
D. 20 mm
Answer» B. 5 mm
45.

Applications in which stresses are encountered in one direction only uses following type of threads

A. metric
B. buttress
C. acme
D. square
Answer» C. acme
46.

If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation

A. 102 d
B. 124 d
C. 138 d
D. 168 d
Answer» E.
47.

Elastic nut is a locking device in which

A. one small nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
B. a slot is cut partly in middle of nut and then slot reduced by tightening a screw
C. hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is stewed on the bolt causing a tight grip
D. through slots are made at top and a cotter-pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at other end
Answer» D. through slots are made at top and a cotter-pin is passed through these and a hole in the bolt, and cotter pin splitted and bent in reverse direction at other end
48.

Eye bolts are used for

A. foundation purposes
B. locking devices
C. absorbing shock and vibrations
D. lifting and transportation of machines and cubicles.
Answer» E.
49.

A tapered key which fits in a keyway in the hub and is flat on the shaft, is known as

A. wood-ruff key
B. feather key
C. flat saddle key
D. gib head key
Answer» D. gib head key
50.

A key made from a cylindrical disc having segmental cross-section, is known as

A. wood-ruff key
B. feather key
C. flat saddle key
D. gib head key
Answer» B. feather key