ISRO Scientist or Engineer Mechanical 2006

ISRO Scientist or Engineer Mechanical 2006 - Question 1

Report

In nodular iron, graphite is in the form of

A

Cementite

B

Free carbon

C

Flakes

D

Spheroids

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 2

Report

Hardness of steel depends on

A

Amount of carbon it contains

B

The shape and distribution of the carbides in iron

C

Method of fabrication

D

Contents of alloying elements

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 3

Report

Too high welding current in arc welding would result in

A

Excessive spatter, under cutting along edges, irregular deposits, wasted electrodes

B

Excessive piling up of weld metal, poor penetration, wasted electrodes

C

Too small bead, weak weld and wasted electrodes

D

Excessive piling up of weld metal, overlapping without penetration of edges, wasted electrodes

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 4

Report

Which of the following processes would produce strongest components ?

A

Hot rolling

B

Extrusion

C

Cold rolling

D

Forging

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 5

Report

If a quantity Q is dependent on three other quantities $$q_1, q_2 and q_3$$ related such that $$Q = K \times (q_1)^{n_1} \times (q_0)^{n_2} \times (q_3)^{n_3}$$ then overall error $$\frac {\delta Q}{Q} = $$

A

$$n_1 \left( \frac{\delta q_1}{q_1} \right) + n_2 \left( \frac{\delta q_2}{q_2} \right) + n_3 \left( \frac{\delta q_3}{q_3} \right) $$

B

$$\frac{1}{n_1} \frac {\delta q_1}{q_1} + \frac{1}{n_2} \frac {\delta q_2}{q_2} + \frac{1}{n_3} \frac {\delta q_3}{q_3} $$

C

$$ \frac {\delta q_1}{q_1} + \frac {\delta q_2}{q_2} + \frac {\delta q_3}{q_3} $$

D

$$\left( \frac {\delta q_1}{q_1} \right)^{n_1} + \left( \frac {\delta q_2}{q_2} \right)^{n_2} + \left( \frac {\delta q_3}{q_3} \right)^{n_3} $$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 6

Report

Which of the following has maximum hardness

A

Austenite

B

Pearlite

C

Troostite

D

Martensite

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 7

Report

The main advantage of line organization is its

A

Effective command and control

B

Defined responsibilities at all levels

C

Rigid discipline in the organization

D

All of the above

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 8

Report

The mathematical technique for finding the best use of limited resources in an optimum manner is known as

A

Operation research

B

Linear programming

C

Network analysis

D

Queuing theory

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 9

Report

Which of the following errors are generally distributed in accordance with the Gaussian distribution

A

Controllable errors

B

Calibration errors

C

Avoidable errors

D

Random errors

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 10

Report

$$\frac {PL^3}{3EI}$$ Is the deflection under the load P of a cantilever beam (length L, modulus of elasticity E, moment of inertia I). The strain energy due to bending is

A

$$\frac {P^2L^3}{3EI}$$

B

$$\frac {P^2L^3}{6EI}$$

C

$$\frac {P^2L^3}{4EI}$$

D

$$\frac {P^2L^3}{48EI}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 11

Report

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

A

1 kg

B

1.6 kg

C

2 kg

D

2.4 kg

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 12

Report

A short column of external diameter D and internal diameter d carries an external load W. The greatest eccentricity which the load can have without producing tension on the cross section of the column is

A

$$\frac {(D + d)}{8}$$

B

$$\frac {(D^2 + d^2)}{8}$$

C

$$\frac {(D^2 + d^2)}{8D}$$

D

$$\frac {(D^2 + d^2)}{8d}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 13

Report

If the radius of wire stretched by a load doubled, then its Young’s modulus will

A

Be doubled

B

Be halved

C

Become four times

D

None of the above

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 14

Report

Longitudinal stress in a thin cylinder subjected to internal pressure is

A

Half of the hoop stress

B

Twice the hoop stress

C

Equal to the hoop stress

D

One-fourth the hoop stress

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 15

Report

Maximum deflection in cantilever due to pure bending moment M at its end is

A

$$\frac {ML^2}{2EI}$$

B

$$\frac {ML^2}{3EI}$$

C

$$\frac {ML^2}{4EI}$$

D

$$\frac {ML^2}{6EI}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 16

Report

If Poisson’s ratio for a material is 0.5, then the elastic modulus for the material is

A

3 times its shear modulus

B

4 times its shear modulus

C

Equal to its shear modulus

D

Indeterminate

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 17

Report

A cantilever beam of negligible weight is carrying a mass at its free end, and is also resting on an elastic support of stiffness $$k_1$$ as shown in the figure below.If $$k_2$$ represents the bending stiffness of the beam, the natural frequency (rad/s) of the system is

A

$$\frac {\sqrt {(k_1 k_2)}}{M} {(k_1 + k_2)}$$

B

$$\frac {{\sqrt 2 }(k_1 + k_2)}{M}$$

C

$$\frac {\sqrt {(k_1 + k_2)}}{M} $$

D

$$\frac {\sqrt {(k_1 - k_2)}}{M} $$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 18

Report

The figure shows 3 small spheres that rotate about a vertical axis. The perpendicular distance between the axis and the center of each sphere is given. Mass of highest rotational inertia about that axis, is

A

36

B

4

C

9

D

All same

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 19

Report

Which of the following relationships between the force F on a particle and the particlees position x implies simple harmonic oscillation

A

$$F = -7X$$

B

$$F = -200x^2$$

C

$$F = 10x$$

D

$$F = 5x^2$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 20

Report

A mass of 100 kg is held between two springs as shown in figure. The natural frequency of vibration of the system in cycles/second is

A

$$\frac {10}{\pi}$$

B

$$\frac {5}{\pi}$$

C

$$\frac {1}{2 \pi}$$

D

$$\frac {20}{\pi}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 21

Report

The bending equation is written as

A

$$\frac {I}{M} = \frac {f}{y} = \frac {E}{R}$$

B

$$\frac {M}{I} = \frac {f^2}{y} = \frac {E^2}{R^2}$$

C

$$\frac {M}{I} = \frac {f}{y} = \frac {E}{R}$$

D

$$\frac {M^2}{I} = \frac {f^2}{y} = \frac {E^2}{R}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 22

Report

Hydraulic testing of boilers is done at pressures

A

Below and above atmosphere

B

Slightly above atmospheric pressure

C

At half the working pressure of boiler

D

At 1.5 to 2 times the working pressure

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 23

Report

100 m of water column is equal to

A

$$1000 kN/m^2$$

B

$$100 kN/m^2$$

C

$$10 kN/m^2$$

D

$$1 kN/m^2$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 24

Report

Gantry girders are invariably designed to resist

A

Transverse loads only

B

Lateral loads only

C

Transverse and lateral loads

D

Transverse, lateral and axial load

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 25

Report

If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former,
then energy stored in the later at the same speed will be

A

Four times the first one

B

Same as the first one

C

One fourth of the first one

D

One and a half times the first one

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 26

Report

A thin circular disc is rolling with a uniform linear Speed, along a straight path on a plane surface. Consider the following statements in this regard:
1. All points of the disc have the same velocity
2. The center of the disc has zero acceleration
3. The center of the disc has centrifugal acceleration
4. The point on the disc making contact with the plane surface has zero acceleration
Of these statements

A

1 and 4 are correct

B

3 and 4 are correct

C

3 alone is correct

D

2 alone is correct

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 27

Report

If a number of forces act on a rigid body, each force may be replaced by an equal and parallel force acting through a fixed point, together with a couple. For the rigid body to be in equilibrium

A

Both resultant force and couple must be zero

B

The resultant couple on the body must be zero

C

The resultant force at the fixed point must be zero

D

None of the above need be zero

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 28

Report

Whir ling speed of a shaft coincides with the natural frequency of its

A

Longitudinal vibration

B

Transverse vibration

C

Torsional vibration

D

Coupled bending torsional vibration

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 29

Report

A fixed gear having 200 teeth is in mesh with another gear having 50 teeth. The two gears are connected by an arm. The number of turns made by the smaller gear for one revolution of arm about the center of the bigger gear is

A

4

B

3

C

$$\frac{2}{4}$$

D

5

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 30

Report

With symbols having the usual meanings,the single degree of freedom system, $$mx + cx + kx = F \sin \omega t$$ represents

A

Free vibrations with damping

B

Free vibrations without damping

C

Forced vibrations with damping

D

Forced vibrations without damping

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 31

Report

In the two - rotor system shown in the figure, $$(I_1 < I_2)$$, a node of vibration is situated

A

Between $$I_1$$ and $$I_2$$ but nearer to $$I_1$$

B

Between $$I_1$$ and $$I_2$$ but nearer to $$I_2$$

C

Exactly in the middle of the shaft

D

Nearer to $$I_1$$ but outside

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 32

Report

Which one of the following is not a friction clutch?

A

Disc or plate clutch

B

Cone clutch

C

Centrifugal clutch

D

Jaw clutch

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 33

Report

Polar moment of inertia $$(I_p)$$ of a circular disc is to be determined by suspending it by a wire and noting the frequency of oscillations (f)

A

$$I_p \alpha \frac {1}{f^2}$$

B

$$I_p \alpha {f^2}$$

C

$$I_p \alpha {f}$$

D

$$I_p \alpha \frac {1}{f}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 34

Report

Pick up the wrong statement. A flywheel

A

Is usedto limit the inevitable fluctuation of speed during each cycle

B

Controls the mean speed of rotation

C

Stores up energy and gives up whenever required

D

Regulates the speed during one cycle of a prime mover

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 35

Report

Purpose of using differential gear in automobile is to

A

Help in turning

B

Control speed

C

Avoid jerks

D

Obtain rear movement

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 36

Report

The acceleration of Simple Harmonic Motion of a pendulum is proportional to

A

Length of pendulum

B

Time period

C

Angular velocity

D

Displacement

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 37

Report

A person walks up a stalled escalator in 90 seconds. When standing on the same escalator, now moving, he is carried up in 60 seconds. How much time would it take him to walk up the moving escalator?

A

30 sec

B

36 sec

C

45 sec

D

54 sec

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 38

Report

A stone of mass m at the end of a string of length l is whirled in a vertical circle at a constant speed. The tension in the string will be maximum when the stone is

A

At the top of the circle

B

Half-way down from the top

C

Quarter-was downfrom the top

D

At the bottom of the circle

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 39

Report

Speed of particl e executing simple harmonic motion with amplitude a is half of the maximum speed. At that instant , displacement of the particle is

A

$$\frac{a}{2}$$

B

$$\frac{\sqrt 3}{2} a$$

C

$$\frac{2a}{\sqrt 3}$$

D

$$3 \sqrt 2 a$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 40

Report

Two satellites, of masses m and 2m, are on the same circular orbit around earth. If the velocity of the lighter satellite is $$v_0$$, what is the
velocity of the heavier satellite?

A

$$\frac{1}{2} v_0$$

B

$$v_0$$

C

$$2 v_0$$

D

$$\frac{1}{4} v_0$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 41

Report

$$N_u = CR_{e}^{m} P_{r}^{n}$$ represents heat transfer under

A

Free convection

B

Forced convection

C

Combined convection

D

None of the above

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 42

Report

If the inner and oute r surfaces of a hollow cylinder (having radii $$r_1 and r_2$$ and length L) are at temperatures $$t_1 and t_2$$ then rate of radial heat flow will be

A

$$\frac {k}{2\pi L} \frac {t_1 -t_2}{\log \frac{r_2}{r_2}}$$

B

$$\frac {1}{2\pi Lk} \frac {t_1 -t_2}{\log \frac{r_2}{r_1}}$$

C

$$\frac {2\pi L}{k} \frac {t_1 -t_2}{\log \frac{r_2}{r_1}}$$

D

$$2 \pi Lk \frac {t_1 -t_2}{\log \frac{r_2}{r_1}}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 43

Report

For infinite parallel planes with emissivities $$\epsilon_1 and \epsilon_2,$$ the interchange factor for radiation from surface 1 to surface 2 is given by

A

$$\frac {\epsilon_1 \epsilon_2}{\epsilon_1 + \epsilon_2 - \epsilon_1 \epsilon_2}$$

B

$$\frac{1}{\epsilon_1} + \frac {1}{\epsilon_2}$$

C

$$\epsilon_1 + \epsilon_2$$

D

$$\epsilon_1 \epsilon_2$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 44

Report

For a closed system, difference between the heat added to the system and work done by the gas, is equal to the change in

A

Internal energy

B

Entropy

C

Enthalpy

D

Temperature

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 45

Report

The condition for reversibility of a cycle is

A

Cyclic $$\int \frac {dQ}{T} < 0$$

B

Cyclic $$\int \frac {dQ}{T} > 0$$

C

Cyclic $$\int \frac {dQ}{T} = 0$$

D

None of these

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 46

Report

The state of a real gas if changed from pressure $$P_1,$$ temperature $$T_1$$ to pressure $$P_2$$ temperature $$T_2.$$ The change in enthalpy, $$h_2 - h_1,$$ is given by

A

$$\int_{T_1}^{T_2} C_p dT $$

B

$$\int_{T_1}^{T_2} C_p dT + \int_{p_1}^{p_2} \left( \frac{\delta V}{\delta P} \right)_T dp$$

C

$$\int_{T_1}^{T_2} C_v dT + \int_{p_1}^{p_2} \left[ V - T \left(\frac{\delta V}{\delta T}\right)_p \right] dp$$

D

$$\int_{T_1}^{T_2} C_p dT + \int_{p_1}^{p_2} \left[ V - T \left(\frac{\delta V}{\delta T}\right)_p \right] dp$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 47

Report

One hundredth of a kilogram of air is compressed in a piston-cylinder device. At an instant of time when T = 400 K, the rate at which work is being done on the air is 8.165 kW, and heat is being removed at a rate of 1.0 kW, the rate of temperature rise will be

A

10 K/s

B

100 K/s

C

1000 K/s

D

10000 K/s

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 48

Report

The volume V versus temperature T graphs for a certain amount of a perfect gas at two pressure $$P_1 and P_2$$ are as shown in the figure. It can be concluded that

A

The pressure $$P_1$$ is greater than the pressure $$P_2$$

B

The adiabatic index for $$P_1$$ is higher than that for $$P_2$$

C

$$P_1$$ represents monoatomic gas and $$P_2$$ represents diatomic gas

D

None of the above

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 49

Report

In the polytropic process $$pv^n$$ = Constant,if n = 1 the process will be at

A

Constant volume

B

Constant pressure

C

Constant temperature

D

Adiabatic

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 50

Report

In case of ideal triatomic gas,the ratio of specific heats $$\frac{C_p}{C_v} would be

A

1

B

1.33

C

1.40

D

1.41

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 51

Report

The formation of frost on cooling coils in a refrigerator

A

Increases power consumption

B

Improves C.O.P. of the system

C

Increases heat transfer

D

Reduces power consumption

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 52

Report

An air-conditioned room has one of the walls, which is $$5m \times 3m$$ of 3.75 cm thick brick. The conditioned space is maintained at $$27^\circ C$$ when the outside temperature is $$47^\circ C$$. Variation of thermal conductivity with temperature of the wall is given by $$k = 1 + 2 \times 10^{-4}T, where T is in degree Kelvin, and k is in $$W/m^\circ K$$. The heat gained by the conditioned space through this wall is

A

849.6 W

B

84.96 W

C

800 W

D

0

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 53

Report

A mild steel tank of wall thickness 12 mm contains water at $$100^\circ C$$. The atmospheric temperature is $$20^\circ C$$. The thermal conductivity of mild steel is $$50 W/mK$$, and the heat transfer co-efficients for inside and outside the tank are 2850 and $$10 W/m^2 K$$, respectively. Calculate the rate of heat loss per $$m^2$$ of tank surface and the temperature of the outside surface of the tank.

A

$$300.5 W/m^2, 45.5^\circ C$$

B

$$495.2 W/m^2, 67.6^\circ C$$

C

$$602.6 W/m^2, 80.6^\circ C$$

D

$$795.2 W/m^2, 99.52^\circ C$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 54

Report

In order to burn 1 Kg of CH4 completely the minimum number of kilograms of Oxygen needed is (take atomic weight of H, C, O as 1, 12, 16 respectively)

A

3

B

6

C

5

D

4

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 55

Report

The vector field $$\overrightarrow{F} = x\widehat{i} - y\widehat{j}$$ (where $$\widehat{i}$$ and $$\widehat{j}$$ are unit vectors) is

A

Divergence free, but not irrotational

B

Irrotational, but not divergence free

C

Divergence free and irrotational

D

Neither divergence free nor irrotational

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 56

Report

For flow through a horizontal pipe, the pressure gradient $$\frac {dp}{dx} in the flow direction is

A

+ve

B

1

C

Zero

D

-ve

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 57

Report

The transition Reynolds number for flow over a flat plate is $$5 \times 10^5.$$ What is the distance from the leading edge at which transition will occur for flow of water with a uniform velocity of 1 m/s ? (For water, the kinematic viscosity, $$\upsilon = 0.858 \times 10^{-6} m^2/s)$$

A

1 m

B

0.43 m

C

43 m

D

103 m

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 58

Report

Between section 1 and 2 of a pipe a pump, a heater, a very rough pipe and an orifice plate are placed. The Bernoulli equation can be applied between 1 and 2 if

A

Orifice plate and heater are removed

B

Heater pump and heater are removed

C

Heater and pump are removed

D

Heater, rough pipe and orifice plates are removed

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 59

Report

A one dimensional flow is one which

A

Is uniform flow

B

Is steady uniform flow

C

Takes place in straight lines

D

Involves zero transverse component of flow

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 60

Report

A piece weighing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specific gravity is

A

1

B

5

C

6

D

7

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 61

Report

The actual velocity at vena contracta for flow through an orifice from a reservoir of height H =

A

$$\sqrt 2gH$$

B

$$C_v \sqrt 2gH$$

C

$$\sqrt 2gH/ C_v$$

D

$$C_d \sqrt 2gH$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 62

Report

The horizontal component of force on a curved surface is equal to the

A

Product of pressure at its centroid and area

B

Weight of liquid retained by the curved area

C

Force on a vertical projection of the curved surface

D

Weight of liquid vertically above the curved surface

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 63

Report

The maximum depth from which a centrifugal pump can draw water is

A

Dependent on the speed N of the pump

B

Dependent on the power of the pump

C

Around 10 m

D

Dependent on $$N^2$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 64

Report

Two pipe lines at a different pressures, $$p_A$$ and $$p_B,$$ each carrying the same liquid of specific gravity $$S_1$$ are connected to a U tube with a liquid of specific gravity of $$S_2$$ resulting in the level differences $$h_1, h_2 and h_3$$ as shown in the figure. The difference in pressure head between points A and B in terms of head of water is

A

$$h_1 S_2 + h_2 S_1 + h_3 S_1$$

B

$$h_1 S_1 + h_2 S_2 - h_3 S_1$$

C

$$h_1 S_1 - h_2 S_2 - h_3 S_1$$

D

$$h_1 S_1 + h_2 S_2 + h_3 S_1$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 65

Report

List I gives 4 dimensionless numbers andList II gives the types of forces, which are one of the constituents describing the numbers. Match list I with List II and select the correct answer using the codes given below the lists:

A

A - 2, B - 3, C - 4, D - 5

B

A - 3, B - 2, C - 4, D - 5

C

A - 1, B - 2, C - 5, D - 4

D

A - 2, B - 1, C - 5, D - 4

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 66

Report

A single-stage impulse turbine with a diameter of 120 cm runs at 3000 rpm. If the blade speed ratio is 0.42, then, the inlet velocity of steam will be

A

79 m/s

B

188 m/s

C

450 m/s

D

900 m/s

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 67

Report

For laminar flow over a flat plate, the thickness of the boundary layer at a distance from the leading edge is found to be 5 mm. The thickness of the boundary layer at a downstream section, which is at twice the distance of the previous section from the leading edge, will be

A

10 mm

B

$$5 \sqrt 2 mm$$

C

$$\frac {5}{\sqrt 2} mm$$

D

2.5 mm

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 68

Report

If $$U_\infty$$ = free stream velocity, u = velocity at y, and $$\delat = boundary layer thickness, then in a boundary layer flow, the momentum thickness $$\theta$$ is given by

A

$$\theta = \int_{0}^{\delta} \frac {u}{U_\infty} \left( 1 - \frac {u}{U_\infty}\right) dy$$

B

$$\theta = \int_{0}^{\delta} \frac {u}{U_\infty} \left( 1 - \frac {u^2}{U_\infty ^2}\right) dy$$

C

$$\theta = \int_{0}^{\delta} \frac {u^2}{U_\infty^2} \left( 1 - \frac {u}{U_\infty}\right) dy$$

D

$$\theta = \int_{0}^{\delta} \left( 1 - \frac {u}{U_\infty}\right) dy$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 69

Report

An automobile moving at a velocity of 40 km/hr is experiencing a wind resistance of 2kN. If the automobile is moving at a velocity of 50km/hr, the power required to overcome the wind resistance is

A

43.4 kW

B

3.125 kW

C

2.5 kW

D

27.776 kW

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 70

Report

A cons tant-head water tank has, on one of its vertical sides two identical small orifices issuing two horizontal jets in the same vertical plane. The vertical distance between the centers of orifices is 1.5 m and the jet trajectories intersect at a point 0.5 m below the lower orifice. What is the approximate height of water level in the tank above the point of intersection trajectories?

A

1.0 m

B

2.5 m

C

0.5 m

D

2.0 m

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 71

Report

A unit vector perpendicular to the vectors $$\overrightarrow{a} = 2i - 3j + k$$ and $$\overrightarrow{b} = i + j - 2k,$$ is

A

$$\frac {1}{\sqrt 3} (-i + j + k)$$

B

$$\frac {1}{\sqrt 3} (i + j - k)$$

C

$$\frac {1}{\sqrt 3} (i + j + k)$$

D

$$(i + j + k)$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 72

Report

The region of the z plane for which $$|\frac {z - a}{z + a}| = (Re a \neq 0)$$ is

A

x-axis

B

y-axis

C

The straight line $$z = |a|$$

D

None of the above

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 73

Report

If $$\alpha, \beta, \gamma$$ are the roots of equations $$X^3 + Px^2 + qx + p = 0$$, Then the value of $$\tan^{-1} \alpha + \tan^{-1} \beta + \tan^{-1} \gamma$$ is

A

$$\frac {n \pi}{2}$$

B

$$n \pi$$

C

$$2 n \pi$$

D

$$\frac{n \pi}{4}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 74

Report

The value of the determinant 

is

A

0

B

1

C

(a + b + c)

D

3

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 75

Report

The value of $$\int_{0}^{1} \int_{0}^{1} \frac{dx dy} {\sqrt{ (1 -x^2)(1 - y^2)}}$$ is

A

$$\frac {\pi^2}{2}$$

B

$$\frac {\pi}{4}$$

C

$$\frac {\pi^2}{4}$$

D

$$\frac {\pi}{2}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 76

Report

Solution of $$(D^2 + 16)y = \cos 4x,$$ is

A

$$y = A \cos 4x + B \sin 4x + \frac{1}{8} \cos 4x$$

B

$$y = A \cos 4x + B \sin 4x + \frac{x}{8} \sin 4x$$

C

$$y = A \cos 4x + B \sin 4x + \frac{1}{8} \sin 4x$$

D

$$y = A \cos 4x + B \sin 4x + \frac{x}{8} \cos 4x$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 77

Report

Laplace transform of $$t^2 + 2t + 3$$ is

A

$$\frac {-2}{s^3} - \frac {2}{s^2} - \frac {3}{s}$$

B

$$\frac {2}{s^3} + \frac {2}{s^2} - \frac {3}{s}$$

C

$$\frac {2}{s^3} + \frac {2}{s^2} + \frac {3}{s}$$

D

$$\frac {-2}{s^3} + \frac {2}{s^2} - \frac {3}{s}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 78

Report

Equation of a straight line passing through the point (-1,2) and making equal intercepts on the axes is

A

$$x - y = 1$$

B

$$x - 2y = 1$$

C

$$x + y = 1$$

D

$$x - y = 2$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 79

Report

A bag contains eight white and six red marbles. The probability of drawing two marbles of same colour is

A

$$\frac {8c_2.6C_2}{14c_2}$$

B

$$\frac {8c_2}{14c_2} + \frac {6c_2}{14c_2}$$

C

$$\frac {8c_2.6C_2}{14c_2.14c_2}$$

D

$$\frac {8c_2}{14c_2} + \frac {6c_2}{12c_2}$$

View Solution

ISRO Scientist or Engineer Mechanical 2006 - Question 80

Report

The Algebraic multiplicity of the matrix $$A = \begin{bmatrix}0 & 1 & 0 \\0 & 0 & 1 \\ 1 & -3 & 3 \end{bmatrix}$$ is

A

1

B

2

C

3

D

4

View Solution