Mechanical Engineering
1 What state the first law of Thermodynamics?
Conservation of Energy
Conservation of Momentum
Conservation of Mass
Conservation of Charge
2 At any point on the saturation curve in psychometric chart, the dry bulb temperature is always
Equal to the corresponding wet bulb temperature
More than the corresponding wet bulb temperature
Less than the corresponding wet bulb temperature
Cannot predict
3 For the same capacity of plant, the COP of the vapour absorption refrigeration system is
Lower than the COP of the vapour compression refrigeration system
Higher than the COP of the vapour compression refrigeration system
Same as the COP of the vapour compression refrigeration system
cannot say
4 For a same pressure the saturation temperature of ammonia is
Lower than the saturation temperature of water
Higher than the saturation temperature of water
Same as the saturation temperature of water
None of these
5 What is an advantage using analyser-rectifier in aqua-ammonia absorption system?
It prevents expansion valve from blocking due to ice formation
It makes ammonia-water solution strong
It prevents expansion valve from blocking due to ice formation
Both it prevents expansion valve from blocking due to ice formation and it makes ammonia-water solution strong
6 Which among the following engines is NOT the type of aircraft gas turbine which works on jet propulsion cycle?
None of these
Turboprop
Turbofan
Turbojet
7 The maximum limit of the pressure ratio of the Brayton cycle for maximum efficiency
Is equal to the pressure ratio of the Carnot cycle
Is more than the pressure ratio of the Carnot cycle
Is less than the pressure ratio of the Carnot cycle
Can not say
8 The feed water heater in which the extracted steam and feed water have thermal contact for exchanging heat but the extracted steam is not allowed to mix with the feed water is called as
Closed type feed water heater
Contact type feed water heater
Open type feed water heater
None of these
9 When the thermodynamic criterion of equilibrium (H, S, U, G or F) remains constant for all possible variation of finite magnitude then the system is said to be in
Neutral equilibrium
Meta-stable equilibrium
Unstable equilibrium
None of these
10 What is the dryness fraction (x) for saturated water, when water just starts boiling?
x = 0
x = 1
x = 0.9
x = 0.5
11 If m1 and m2 are the masses of liquid and vapour respectively in a liquid-vapour mixture, then what is the formula for dryness fraction x?
x = m2 / (m1 + m2)
x = m1 / (m1 + m2)
x = (m1 + m2) / m2
x = (m1 + m2) / m1
12 Arbitrarily, the value of triple point is taken as
273.16 K
273.16 Degree C
0 K
None of These
13 The ratio of effective length and least lateral dimension for short column is _______
< 12
> 12
≥ 12
None of these
14 In Euler’s theory, long columns having the ratio of (Le /LLD) ≥ 12 fail due to _______
Buckling
Both buckling and crushing
Crushing
All of these
15 Euler’s formula is applicable only _________ 1. for short columns 2. for long columns 3. if slenderness ratio is greater than √(π2 E / σc) 4. if crushing stress < buckling stress 5. if crushing stress ≥ buckling stress
2, 3 and 5
1, 2 and 3
3 and 4
All of these
16 What is the relation between actual length and effective length while determining crippling load for a hollow rectangular cast iron column having both ends fixed? (where L= actual length and Le =effective length)
Le = L/2
Le = 4L
Le = 2L
Le = L
17 When a component is subjected to axial stress the normal stress σn is maximum, if cos θ is _______ . (σn=σxCos2θ) 1. maximum 2. minimum 3. always one 4. always zero
1 and 3
1 and 4
2 and 3
2 and 4
18 Virtual number of teeth on pinion of bevel gear is calculated using the formula __________ (where zp = number of teeth on pinion, γp & γg = pitch cone angle)
zp / cos γp
zp / cos γg
zp / cos2 γp
zp / cos3 γp
19 What is the axial force acting on the pinion if a bevel gear transmits power of 20 kW with a mean pitch line velocity of 5 m/s? (Consider γp = 25o & Φ = 15o)
452.96 N
971.37 N
1801.67 N
1865 N
20 At zero acceleration a particle moves along a straight line. What is the velocity of a particle at the position of x = t4 -20t2 + 42 ?
+ 48.68 m/sec
– 48.68 m/sec
+ 42 m/sec
– 42 m/sec
21 What is the initial velocity of an object which travels a distance of 10t2 +15t + 5 along a straight line in time t?
+15
-15
+10
-10
22 Two cars X and Y move on adjacent roads in opposite directions. If velocity of car X and Y is 80 km/hr and 60 km/hr respectively, then what will be the relative velocity of car X w.r.t. Y?
140 km/hr
100 km/hr
70 km/hr
Insufficient data
23 What is the maximum distance traveled by a block moving upwards on an inclined plane of 30o with velocity of 20 m/s, if coefficient of friction is 0.23 between the block and inclined plane?
29.19 m
22.56 m
17.32 m
17.00 m
24 What is the path equation for a particle having x = 6t and y = 4t^2 ?
x^2 = 6y
x^2 = 9y
y^2 = 8x
y = 9x
25 A particle moves along a path y = x2 – 6x + 200. If vx = 6 m/s , what is the value of vy at x = 30?
324 m/s
300 m/s
354 m/s
None of these
26 A car moves along a circular arc at a speed of 30 m/s, if speed of the car is increased at the rate of 50 m/s^2, what is the resultant acceleration of the car? (Radius of arc = 15 m)
78.10 m/s^2
33.16 m/s^2
60.23 m/s^2
58.10 m/s^2
27 Which of the following factors are related by work energy principle?
Force, velocity, displacement
Force, velocity, time and mass
Force, displacement and time
Displacement, time and mass
28 If coefficient of restitution is zero during plastic impact, then ___________
Momentum energy is conserved
Kinetic energy is conserved
Bodies move away after impact
All of these
29 Coefficient of restitution is the ratio of impulse during __________
Restoration period and deformation period
Deformation period and restoration period
Plastic deformation and elastic deformation
Elastic deformation and plastic deformation
30 Which of the following conditions is satisfied for cantilever truss?
n = 2j – R
n ≠ 2j – R
n < 2j – R
n > 2j – R
31 What is the relation between tight side and slack side for a flat belt?
(Tight side / slack side) = eμβ
(Tight side + slack side) = eμβ
(Tight side x slack side) = eμβ
None of these
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