ISRO Mechanical Engineering : Practice Mock Test 4
Attempt now to get your rank among 2283 students!
Question 1
Materials exhibiting time bound behavior are known as
Question 2
Which is false statement about annealing?
Annealing is done to
Question 3
Hardness of martensite is about
Question 4
Which of the following order of crystal structure will match with metals Iron — Copper — Zinc in that order?
Question 5
Laplace transform of sin3 2t is
Question 6
Eigen values of are
Question 7
There are 20 locks and 20 matching keys. Maximum number of trials required to match all the locks is
Question 8
A stone is projected horizontally from a cliff at 10 m/sec and lands on the ground below at 20 m from the base of the cliff. Find the height of the cliff. Use g=10 m/sec2
Question 9
A boat which has a speed of 5 km/h in still water crosses a river of width 1 km along the shortest path in 15 min. The velocity of the river in km/h is
Question 10
A two member truss ABC is configured as shown in figure. The force in the member AB is
Question 11
A car moving with uniform acceleration covers 450 m in a 5 second interval, and covers 700 m in the next 5 second interval. The acceleration of the car is
Question 12
Chances of occurrence of cavitation are high if the
Question 13
The general equation of continuity for three-dimensional flow of a incompressible fluid for steady flow is
Question 14
If a Jet of water of area ‘A ’ strikes with velocity ‘V ’ a series of flat plates wheel of mean diameter D rotating at N rpm, then force exerted will be equal to
Question 15
A steady, incompressible, two-dimensional velocity field is given by V = (0.5 + 0.8x)i +(1.5 - 0.8y) j The number of stagnation points there in the flow field is
Question 16
A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. Assume that the water doesn't spill after immersing weight inside the bucket.The spring balance reading will
Question 17
If the stream function is given by, then the velocity at a point (2,3) will be
Question 18
If=free stream velocity, u = velocity at y,and= boundary layer thickness, then in a boundary layer flow, the momentum thickness is
Question 19
The transition Reynolds number for flow over a flat plate is 5 x105. What is the distance from the leading edge at which transition will occur for flow of water with a uniform velocity of 1m/s? (For water, the kinematic viscosity, v = 0.858x 10-6m2/s)
Question 20
Multi stage centrifugal pumps in series are used for
Question 21
Match List I with List-II and select the correct answer
Where,Centre of gravity =G, Meta Centre = M, Weight of floating body = W, Buoyant force= FB
Question 22
It is required to insulate a kitchen oven with cork board (K=0.043 W/(m K)) so that the heat losses from the oven does not exceed 400 W/m2 when the inner surface of the oven is at 225 °C and the outer surface of the oven is at 40 °C. The thickness of insulation required is nearly
Question 23
The transmission of heat by molecular collision is called
Question 24
The heat flow rate through parallel walls of thickness L1, L2 and L3 having surface areas A1, A2 and A3, thermal conductivities k1 ,k2 , and k3 respectively, with the first and last walls maintained at temperatures t1 and t2 will be
Question 25
The radiative heat transfer rate per unit area (W/m2) between two plane parallel grey surfaces (emissivity = 0.9) maintained at 400 K and 300 K is (Stefan Bottzman constant = 5.67 x 10-8 W/m2 K4)
Question 26
If two ends of rods of length L and radius r, made of same material are kept at the same temperature difference, which of the following rods conduct most heat per unit time?
Question 27
Which one of the following is not afriction clutch?
Question 28
In a ball bearing, if the number of balls is reduced to half and diameter of the ball is increased to 4 times, then static load capacity of the ball bearing is _________.
Question 29
Which thread is more suited in power screw to take load on both directions?
Question 30
Rivets are made of
Question 31
Spinning operation is carried out on
Question 32
Plug gauges are used
Question 33
In a single micrometer with screw pitch 0.5 mm and divisions on thimble 50, the reading corresponding to 5 divisions on barrel and 12 divisions on thimble is
Question 34
The ultimate tensile strength and yield strength of most of the metals, when temperature rises from 0o C to -150 ° C will
Question 35
A resistance spot-welding operation is performed on two pieces of 1.5 mm thick sheet steel using 12000 amps current for a duration of 0.20 second. The electrodes are 6 mm in diameter at the contacting surfaces. Resistance is assumed to be 0.0001 ohms and the resulting weld nugget is 6 mm in diameter and 2.5 mm thick. The unit melting energy for the metal is 12J/mm3. What portion of heat generated was used to form the weld?
Question 36
Mass production of seamless tubes is by the process of __________.
Question 37
Gantry girders are invariably designed to resist
Question 38
Ring Rolling is used __________.
Question 39
A circular shaft subjected to torsion undergoes a twist of 1 ° in a length of 120 cm. If the maximum shear stress induced is limited to 1000 kg/cm2 and if modulus of rigidity G=0.8×106 Kg/cm2, then the radius of the shaft should be ___________.
Question 40
Which of the following stresses are associated with the tightening of a nut on a stud? 1) Tensile stresses due to stretching of stud. 2) Bending stresses of stud. 3) Transverse shear stresses across threads. 4) Torsional shear stresses in threads due to frictional resistance. Select the correct answer using the codes given below: Codes:
Question 41
When a column is fixed at both ends, corresponding Euler’s critical load is
Question 42
Shear force is
Question 43
A hollow shaft of same cross-section area as solid shaft transmits
Question 44
In a hardness test, L is load in kg, D is diameter of ball in mm and d is diameter of indentation in mm. Brinell Hardness Number is expressed by the equation
Question 45
An Aluminum tensile test specimen has a diameter, do= 25 mm and a gauge length of L0=250mm. If a force of 175 kN elongates the gauge length by 1.25 mm, the modulus of elasticity of the material is nearly
Question 46
In I section shear load is resisted mainly by _________.
Question 47
Purpose of using differential gear in automobile is to _______.
Question 48
A stone of mass m atthe end of a string of length l is whirled in a vertical circle at a constantspeed.The tension in the string will be maximum when thestoneis
Question 49
A simple spring-mass vibrating system has a natural frequency of N. If the spring stiffness is halved and the mass is doubled, then the natural frequency will become
Question 50
Which of the following is a lower pair __________?
Question 51
The density of air at 10 °C and 1 MPa abs, in SI unit is
Question 52
The supply of working fluid to the engine to suit the load conditions is controlled by
Question 53
For a closed system, difference between the heat added to the system and work done by the gas, is equal to the change in
Question 54
The condition for reversibility of a cycle is
Question 55
An aeroplane is flying at an height of 14 km where temperature is -45 °C. The speed of the plane is corresponding to M = 2. Find the speed of the plane if R = 287 J/kgK and
Question 56
A heat engine working with a thermal efficiency of 35% receives 2 kW of heat from a furnace. The waste heat rejected from the engine is
Question 57
Air is heated from 0 °C to 100 °C in a sealed metal container. Its density
Question 58
A thermometer works on the principle of ______.
Question 59
A thin copper wire at 300 ° is suddenly immersed in water at 30 °C. It cools down to 150 °C in 70 seconds. It is then reheated to the initial temperature of 300 °C and suddenly exposed to air at 30 °C where it cools down to 150 °C in 200 seconds. This difference in cooling time is due to
Question 60
The hydraulic diameter, Dh of a rectangular duct with sides 'a' and b' is
Question 61
Which of the following pressure gauge is generally used for the calibration of other pressure measuring gauges ______.
Question 62
A hydraulic press has a ram of 15 cm diameter and plunger of 1.5 cm. It required to lift a mass of 1000 kg. The force required on plunger is nearly equal to
Question 63
Two pipe lines at a different pressures, pA and pB, each carrying the same liquid of specific gravity of Si are connected to a U tube with a liquid of specific gravity of S2 resulting in the level differences hi, h2 and h3 as shown in the figure. The difference in pressure head between points A and B in terms of head of water is
Question 64
and are in equilibrium, if is
Question 65
A and B are two candidates appearing for an interview by a company. The probability that A is selected is 0.5 and the probability that both A and B are selected is at most 0.3. The probability of B getting selected is
Question 66
Equation of the line normal to function f (x) = (x- 8)2/3 + 1 at P(0, 5) is
Question 67
The temperature distribution at a certain input of time in concrete slab during curing is given by T = 3x2 + 3x + 16 where x is in cm and T is in K. The rate of change of temperature with time is given (a = 0.003 cm2/sec)
Question 68
The radiative heat transfer rate per unit area (W/m2) between two plane parallel grey surfaces (emissivity 0.9) maintained at 400 K and 300 K is (Stefan Boltzman constant σ= 5.67× 10–8 W/m2K4) _________.
Question 69
The spectral energy distribution for a body at temperature T is shown in figure. Now if the temperature of the body is increased
Question 70
A flat plate of length 1 m and width 50 cm is placed in an air stream at 30 °C blowing parallel to it. The convective heat transfer coefficient is 30 W/(m2K). The heat transfer if the plate is maintained at a temperature of 400 °C is
Question 71
A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gearsareconnected by an arm. The number of turns made by the smallergearfor one revolution of arm about the center of the bigger gearis
Question 72
Pick up the right statement. A flywheel
Question 73
Only rocket engines can be propelled to space because ________.
Question 74
A steam thermal power plant works on
Question 75
A block is made to slide down an inclined plane (30 ° with horizontal) which is smooth. It starts sliding from rest and takes a time t to reach the bottom of the plane. An identical body is freely dropped from the same point. The time the body takes to reach the bottom is
Question 76
A mass m attached to a light spring oscillates with a period of 2 sec. If the mass is increased by 2 kg, the period increases by 1 sec. The value of m is
Question 77
Two blocks with masses M and m are in contact with each other and are resting on a horizontal frictionless floor. When horizontal force is applied to the heavier, the blocks accelerate to the right. The force between the two blocks are
Question 78
A single-bay car wash with a Poisson arrival rate and exponential service time has cars arriving at an average rate of 10 minutes apart and an average service time of 4 minutes. What is the system utilization______?
Question 79
In the inventory control, if the yearly demand for a certain material is fixed, the economic order quantity gives minimum