ISRO Scientist or Engineer Mechanical 2007

ISRO Scientist or Engineer Mechanical 2007 - Question 1

Report

Only rocket engines can be propelled to space because

A

They can generatevery high thrust

B

They have high propulsion efficiency

C

These engines can work on several fuels

D

Theyare not air-breathing engines

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 2

Report

The universal gas constant of a gas is the product of molecular weight of the gas and

A

Gas constant

B

Specific heat at constant pressure

C

Specific heat at constant volume

D

None of the above

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 3

Report

Vander Waal’s equation of state of a gas is

A

$$pV = nRT$$

B

$$\left(p + \frac{a}{V^2}\right)(v + b) = RT$$

C

$$\left(p + \frac{a}{V^2}\right)(v - b) = RT$$

D

$$\left(p - \frac{a}{V^2}\right)(v - b) = RT$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 4

Report

The radiative heat transfer rate per unit area (W/m$$^2$$) between two plane parallel grey surfaces (emissivity = 0.9) maintained at 400 K and 300 K is (Stefan Bottzman constant
$$\sigma = 5.67 \times 10^{-8} W/m^2 K^4$$)

A

992

B

812

C

464

D

567

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 5

Report

The efficiency $$\eta$$ of any heat engine and efficiency $$\eta_R$$ of a reversible heat engine operating between common heat source and heat sink are related as

A

$$\eta > \eta_R$$

B

$$\eta < \eta_R$$

C

$$\eta \geq \eta_R$$

D

$$\eta \leq \eta_R$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 6

Report

A spherical shaped vessel of 1.4 m outer diameter is 90 mm thick. Find the rate of heat leakage, if the temperature difference between the inner and outer surfaces is $$220^\circ C$$. Thermal conductivity of the material of the sphere is 0.083 W/m K.

A

0.2 kW

B

0.5 kW

C

1.088 kW

D

1.6 kW

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 7

Report

The velocity componentsin the x and y directions are given by $$u = \lambda xy^3 - x^2y; v = xy^2 - \frac{3}{4}y^4$$ The value of $$\lambda$$ for a possible flow field involving an incompressible fluid is

A

$$-\frac{3}{4}$$

B

3

C

$$\frac{4}{3}$$

D

$$-\frac{4}{3}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 8

Report

The temperature field in a body varies according to the equation $$T(x, y) = x^3 + 4xy$$. The direction cf fastest variation in temperature at the point (1, 0) is given by

A

$$3 \hat{i} + 8 \hat{j}$$

B

$$\hat{i}$$

C

$$0.6 \hat{i} + 0.8 \hat{j}$$

D

$$0.5 \hat{i} + 0.866 \hat{j}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 9

Report

The temperature distribution at a certain input of time in concrete slab during curing is given by $$T = 3x^2 + 3x + 16$$ where x is in cm and T is in K. The rate of change of temperature with time is given ($$\alpha = 0.0003 cm^2/sec$$)

A

0.009 K/sec

B

0.0048 K/sec

C

-0.0012 K/sec

D

-0.0018 K/sec

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 10

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300 kJ/sec of heat is applied at a constant fixed temperature of $$290^\circ C$$ to a heat engine. The heat rejection takes place at $$8.5^\circ C$$. then match the following:

A

A-1, B-2, C-3

B

A-2, B-1, C-3

C

A-3, B-2, C-1

D

A-1, B-3, C-2

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 11

Report

If the governing equation fora flow field is given by $$\triangledown^2\phi = 0$$ and the velocity is given by

A

$$\triangledown \times V = 0$$

B

C

D

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 12

Report

With rise in temperature thermal conductivity of air

A

Increases

B

Decreases

C

Remains constant

D

Mayincrease or decrease depending on temperature

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 13

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In a reversible adiabatic process, the ratio of $$\frac{T_1}{T_2}$$ is equal to

A

$$\left(\frac{p_1}{p_2}\right)^{\frac{\gamma - 1}{\gamma}}$$

B

$$\left(\frac{p_2}{p_1}\right)^{\frac{\gamma - 1}{\gamma}}$$

C

$$\left(\frac{v_1}{v_2}\right)^{\frac{\gamma - 1}{\gamma}}$$

D

$$\left(\frac{v_2}{v_1}\right)^{\frac{\gamma - 1}{\gamma}}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 14

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Chances of occurrenceof cavitation are high if the

A

Local pressure becomes very high

B

Local pressure falls below the vapour pressure

C

Thoma cavitation parameter exceeds a certain limit

D

Local temperature becomes low

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 15

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The general equation of continuity for three-dimensional flow of a incompressible fluid for steady flow is

A

$$\frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial z} = 0$$

B

$$\frac{\partial u}{\partial x} = \frac{\partial v}{\partial y} = \frac{\partial w}{\partial z} = 0$$

C

$$\frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial z} = 1$$

D

$$\frac{\partial u}{\partial x} + \frac{\partial v}{\partial y} + \frac{\partial w}{\partial z} = u.v.w$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 16

Report

A liquid compressedin cylinder has a volume of 0.04 m$$^3$$ at 50 kg/cm$$^2$$ and a volume of 0.039 m$$^3$$ at 150 kg/cm$$^2$$. The bulk modulus of liquid is

A

400 kg/cm$$^2$$

B

4000 kg/cm$$^2$$

C

$$40 \times 10^5 kg/cm^2$$

D

$$40 \times 10^6 kg/cm^2$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 17

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The buoyancy depends on

A

Mass of liquid displaced

B

Viscosity of the liquid

C

Pressure of the liquid displaced

D

Depth of immersion

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 18

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A fluid jet discharging from a 100 mm diameter orifice has a diameter of 80 mmat its vena contracta. The coefficient of contraction is

A

0.8

B

1.25

C

0.2

D

0.64

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 19

Report

If a jet of water of area ‘A’ strikes with velocity ‘V’ a series of flat plates mounted on a wheel of mean diameter D rotating at N rpm, then force exerted will be equal to

A

$$\frac{\rho AV^2}{g}$$

B

$$\frac{\rho AV}{g}\left(V - \frac{\pi DN}{60}\right)$$

C

$$\frac{\rho A}{g} \times \frac{\pi DN}{60}$$

D

$$\rho A\left(V - \frac{\pi DN}{60}\right)$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 20

Report

The maximum height of a siphon for a fluid of specific gravity $$\rho$$ under atmospheric conditions is

A

$$\frac{\rho}{10}$$ meters

B

$$\frac{10(1 + \rho)}{\rho}$$ meters

C

$$\frac{10}{1 - \rho}$$ meters

D

$$\frac{10}{\rho}$$ meters

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 21

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A centrifugal pump with peripheral speed ‘V’ was selected fora total lift of 100 m. Actually pump wasto be operated fora total lift of 400 m. The peripheral speed should actually be (other conditions remaining same)

A

2 V

B

4 V

C

8 V

D

1 V

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 22

Report

The specific speed of pump and turbine respectively are given as

A

$$\frac{N \sqrt{P}}{H^{\frac{5}{4}}}, \frac{N \sqrt{Q}}{H^{\frac{3}{4}}}$$

B

$$\frac{N \sqrt{Q}}{H^{\frac{3}{4}}}, \frac{N \sqrt{P}}{H^{\frac{5}{4}}}$$

C

$$\frac{N \sqrt{P}}{H^{\frac{3}{4}}}, \frac{N \sqrt{Q}}{H^{\frac{5}{4}}}$$

D

$$\frac{N \sqrt{Q}}{H^{\frac{5}{4}}}, \frac{N \sqrt{P}}{H^{\frac{3}{4}}}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 23

Report

Match List I with List II and select the correct answer

A

A-1, B-4, C-2, D-3

B

A-1, B-2, C-4, D-3

C

A-1, B-4, C-3, D-2

D

A-3, B-4, C-1, D-2

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 24

Report

Given that
$$\alpha_1$$ = nozzle angle
n = number of rows of moving blades, in a velocity compounded impulse turbine, the optimum blade speedratio is

A

$$2 \cos \alpha_1 n$$

B

$$\frac{n \cos \alpha_1}{2}$$

C

$$\frac{\cos \alpha_1}{2(n + 1)}$$

D

$$\frac{\cos \alpha_1}{2n}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 25

Report

The following terms relate to floating bodies:
Centre of gravity ... G, MetaCentre ... M, Weight of floating body ... W, Buoyant force ... Fg, Match List I with List II and select the correct answer

A

A-1, B-3, C-2, D-4

B

A-3, B-1, C-4, D-2

C

A-2, B-4, C-1, D-3

D

A-2, B-3, C-4, D-1

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 26

Report

A pipeline connecting two reservoirs has its diameter reduced by 20% due to deposition of chemicals. For a given head difference in the reservoirs with unaltered friction factor, this would cause a reduction in discharge of

A

42.8%

B

20%

C

17.8%

D

10.6%

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 27

Report

An open rectangular box of base 2m $$\times$$ 2m contains a liquid of specific gravity 0.80 up to a height of 2.5 m. If the box is imparted vertically upward acceleration of 4.9m/s$$^2$$, what will be the pressure on the base of the tank?

A

9.81 kPa

B

19.62 kPa

C

36.80 kPa

D

29.40 kPa

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 28

Report

The tank shown in the figure below is closed at top and contains air at a pressure of $$P_A$$. The value of $$P_A$$, for the manometer readings shown will be

A

-3.573 kPa

B

-4.573 kPa

C

-6.573 kPa

D

-7.573 kPa

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 29

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$$P = 2i - 3j, Q = -3i + 4j - 2k$$, and R are in equilibrium, if R is

A

$$-i - j + 2k$$

B

$$i - j + 2k$$

C

$$i + j + 2k$$

D

$$i - j - 2k$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 30

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A rigid body is rotating with constant angular velocity $$\omega$$ about a fixed axis, if v is the velocity of a point of the body, then curl v =

A

$$\omega$$

B

$$\omega^2$$

C

$$2 \omega$$

D

$$2 \omega^2$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 31

Report

Laplace transform of $$\sin^3 2t$$ is

A

$$\frac{24}{(s^2 + 4)(s^2 + 36)}$$

B

$$\frac{1}{(s^2 + 4)(s^2 + 64)}$$

C

$$\frac{48}{(s^2 + 4)(s^2 + 36)}$$

D

$$\frac{64}{(s^2 + 4)(s^2 + 36)}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 32

Report

The value of the determinant 

is

A

0

B

-1

C

1

D

2

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 33

Report

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

A

$$y = A \cos 2x + B \sin 2x - \frac{1}{8} - \frac{x}{8}\sin 2x$$

B

$$y = A \cos 2x + B \sin 2x + \frac{1}{8} + \frac{x}{8}\sin 2x$$

C

$$y = A \cos 2x + B \sin 2x - \frac{1}{8} + \frac{x}{8}\sin 2x$$

D

$$y = A \cos 2x + B \sin 2x + \frac{1}{8} - \frac{x}{8}\sin 2x$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 34

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The value of k for which the lines $$2x + y - 1 = 0, 4x + 3y - 3 = 0$$ and $$3x + ky - 2 = 0$$, are concurrent is

A

-2

B

3

C

2

D

-3

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 35

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A box contains 5 black and 5 red balls. Two balls are randomly picked one after another from the box, without replacement. The probability for both balls being red is

A

$$\frac{1}{90}$$

B

$$\frac{1}{5}$$

C

$$\frac{19}{90}$$

D

$$\frac{2}{9}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 36

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$$x^3 + x \sin x$$ Is a ............ function

A

Constant function

B

Odd function

C

Even function

D

Periodic function

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 37

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$$\int \frac{dx}{x\sqrt{x^2 - a^2}}$$ is

A

$$\frac{1}{a}\cosec^{-1}\left(\frac{x}{a}\right)$$

B

$$\frac{1}{a}\sin^{-1}\left(\frac{x}{a}\right)$$

C

$$\frac{1}{a}\cos^{-1}\left(\frac{x}{a}\right)$$

D

$$\frac{1}{a}\sec^{-1}\left(\frac{x}{a}\right)$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 38

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Eigen values of $$\begin{bmatrix}-5 & 2 \\2 & -2 \end{bmatrix}$$ are

A

-6, -1

B

6, -1

C

-6, 1

D

6, 1

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 39

Report

Hardness of martensite is about

A

RC 65

B

RC 48

C

RC 57

D

RC 80

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 40

Report

Which is false statement about annealing. Annealing is done to

A

Relieve stresses

B

Harden steel slightly

C

Improve machining characteristic

D

Soften material

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 41

Report

Materials exhibiting time bound behavior are known as

A

Visco elastic

B

Anelastic

C

Isentropic

D

Resilient

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 42

Report

Shrinkage allowance is made by

A

Adding to external and internal dimensions

B

Subtracting from external and internal dimensions

C

Subtracting from external dimensions and addingto internal dimensions

D

Adding to external dimensions and subtracting from internal dimensions

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 43

Report

Machinablity depends on

A

Microstructure, physical and mechanical properties and composition of workpiece material

B

Cutting forces

C

Type of chip

D

Tool life

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 44

Report

Spinning operation is carried out on

A

Hydraulic press

B

Mechanical press

C

Lathe

D

Milling machine

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 45

Report

Acceptance sampling is widely used in

A

Batch production

B

Job production

C

Mass production

D

All of the above

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 46

Report

Gratings are used in connection with

A

Flatness measurement

B

Roundness measurement

C

Surface texture measurement

D

Linear displacement measurements

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 47

Report

Which of the following errors are inevitable in the measuring system and it would be vainflul exercise to avoid them

A

Systematic errors

B

Random errors

C

Calibration errors

D

Environmental errors

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 48

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A block whose massis 650 gm is fastened to a spring of spring constant K equals 65 N/m whose other end is fixed. The block is pulled a distance x = 11 cm from its equilibrium position at x = 0 on a smooth surface, and released from rest at t= 0. The maximum speed‘S’ of the oscillating block is

A

11 cm/sec

B

11 m/sec

C

11 mm/sec

D

1.1 m/sec

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 49

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A block of mass‘m’is connected to two springs of stiffness $$K_1$$ and $$K_2$$ as shown in the figure $$f_1$$ and $$f_2$$ are the frequencies of the block when connected to $$K_1$$ and $$K_2$$ independently. Then the frequency of ‘m’ when connected to $$K_1$$ and $$K_2$$ as in the figure is

A

$$f = f_1 + f_2$$

B

$$f = f_1^2 + f_2^2$$

C

$$f = \sqrt{f_1^2 + f_2^2}$$

D

$$f = \sqrt{f_1^2 - f_2^2}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 50

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The block has a kinetic energy of 3J and the spring connecting the block has an elastic energy of 2J (shown in figure). When the block is at x = +2.0 cm. What is the kinetic energy when the block is at x = 0.

A

3J

B

2J

C

1J

D

5J

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 51

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Fora body subjected to direct stresses $$\sigma x, \sigma y$$ and $$\sigma z$$ the direct strain $$ε_x$$ in x direction is (where E and $$\gamma$$ are Young’s Modulus and Poisson’s ratio respectively)

A

$$ε_x = \frac{1}{E}\left\{\sigma x + \gamma(\sigma y - \sigma z)\right\}$$

B

$$ε_x = \frac{1}{E}\left\{\sigma x - \gamma(\sigma y + \sigma z)\right\}$$

C

$$ε_x = \frac{1}{E}\left\{\sigma x - \gamma(\sigma y - \sigma z)\right\}$$

D

$$ε_x = \frac{1}{E}\left\{\sigma x + \gamma(\sigma y + \sigma z)\right\}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 52

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A circular shaft subjected to torsion undergoesa twist of $$1^\circ$$ in a length of 120 cm. If the maximum shear stress inducedis limited to 1000kg/cm$$^2$$ and if modulus of rigidity $$G = 0.8 * 10^6 Kg/cm^2$$, then the radius of the shaft should be

A

$$\frac{\pi}{8}$$ cm

B

$$\frac{\pi}{27}$$ cm

C

$$\frac{18}{\pi}$$ cm

D

$$\frac{27}{\pi}$$ cm

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 53

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A hollow shaft of same cross-section area as solid shaft transmits

A

Same torque

B

Less torque

C

More torque

D

Unpredictable

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 54

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The extension of a mild steel bar 4m long, 2000 mm$$^2$$ cross section under the action of an axial load of 20kN, if E = 2(10$$^5$$) N/mm$$^2$$, is

A

2 mm

B

0.2 mm

C

0.5 mm

D

0.05 mm

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 55

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InIsection shear load is resisted mainly by

A

Flanges only

B

Web only

C

Both by flanges and web

D

None

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 56

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Shear force is

A

Rate of change of loading

B

Sum of bending moments

C

Rate of change of bending moment

D

None of the above

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 57

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Maximum shear stress in Mohr’s circle is equal to

A

Radius of circle

B

Diameter of circle

C

Centerof circle from y-axis

D

Chord ofcircle

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 58

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If a material expands freely dueto heating it will develop

A

Thermal stresses

B

Tensile stress

C

No stress

D

Bending

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 59

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When acolumn is fixed at both ends, corresponding Euler’s critical load is

A

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

B

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

C

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

D

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

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 60

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A metal pipe of 1 m diameter contains a fluid having a pressure of 10 kgf/cm$$^2$$. If the permissible tensile stress in the metal is 200 kgf/cm$$^2$$, then the thickness of the metal required for making the pipe would be

A

5 mm

B

10 mm

C

25 mm

D

20 mm

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 61

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Circumferential and longitudinal strains in the cylindrical boiler under internal steam pressure are $$ε_1$$ and $$ε_2$$ respectively. Change in the volume of the boiler cylinder per unit volume will be

A

$$ε_1 + 2 ε_2$$

B

$$ε_1 ε_2^2$$

C

$$2ε_1 + ε_2$$

D

$$ε_1^2 ε_2$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 62

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lf water in closed pipe freezes, the pipe will

A

Rupture along a plane perpendicular to the axis of pipe

B

Rupture zig-zag along the length

C

Rupture along weakest circumferential section

D

Rupture along line running longitudinally along the pipe

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 63

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The notch angle of Izod impact test specimenis

A

$$10^\circ$$

B

$$20^\circ$$

C

$$20\frac{1}{2}^\circ$$

D

$$45^\circ$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 64

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Which of the following statements regarding laws governing the friction between dry surfacesare correct?
1. The friction force is dependenton the velocity sliding.
2. The friction force is directly proportional to the normal force.
3. The friction force is dependent on the materials of the contact surfaces.
4. The friction force is independent of the area of contact.
Select the correct answer using the codes given below:

A

2, 3 and 4

B

1 and 3

C

2 and 4

D

1, 2, 3 and 4

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 65

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A simple spring-massvibrating system has a natural frequencyof N. If the spring stiffness is halved and the massis doubled, then the natural frequency will become

A

$$\frac{N}{2}$$

B

2N

C

4N

D

8N

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 66

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Under logarithmic decrement, the amplitude of successive vibrations are

A

Constant

B

In arithmetic progression

C

In geometric progression

D

In logarithmic progression

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 67

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Periodic time of simple pendulum is given by

A

$$2\pi \sqrt{\frac{l}{g}}$$

B

$$2\pi \sqrt{\frac{g}{l}}$$

C

$$\frac{1}{2\pi} \sqrt{\frac{g}{l}}$$

D

$$\frac{1}{2\pi} \sqrt{\frac{l}{g}}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 68

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In a single reduction,a large velocity ratio is required. The best transmission is

A

Spur gear drive

B

Helical gear drive

C

Worm gear drive

D

Bevel gear drive

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 69

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Idler pulley is used

A

For changing the direction of motion of the belt

B

For applying tension

C

For increasing velocity ratio

D

All of the above

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 70

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If two bodies one light and other heavy have equal kinetic energies, which onehas a greater momentum

A

Heavy body

B

Light body

C

Both have equal momentum

D

It depends on the actual velocities

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 71

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A heavy block of mass m is slowly placed on a conveyer belt moving with speedv.If coefficient of friction between block and the belt is $$\mu$$, the plock will slide on the pert through distance

A

$$\frac{v}{\mu g}$$

B

$$\frac{v2}{\sqrt{\mu g}}$$

C

$$\left(\frac{v}{\mu g}\right)^2$$

D

$$\frac{v^2}{2 \mu g}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 72

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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

A

7 m/s$$^2$$

B

50 m/s$$^2$$

C

25 m/s$$^2$$

D

10 m/s$$^2$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 73

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A particle starts with a velocity 2m/sec and movesona straight-line track with retardation 0.1 m/sec$$^2$$. The time at which the particle is 15 m from the starting point would be

A

10 sec

B

20 sec

C

50 sec

D

40 sec

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 74

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Two particles with massesin the ratio 1 : 4 are moving with equal kinetic energies. The magnitudeof their linear momentums will conform to the ratio

A

1 : 8

B

1 : 2

C

$$\sqrt{2} : 1$$

D

$$\sqrt{2}$$

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 75

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A stone is projected horizontally from a cliff at 10 m/sec and lands on the ground belowat 20 m, from the baseofthe cliff. Find the height of the cliff. Use g = 10 m/sec$$^2$$ ?

A

18 m

B

20 m

C

22 m

D

24 m

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 76

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Oscillation of a particle is prescribed by the equation $$x = 3 \cos 0.25 \pi t$$ Wheret is the time in seconds.
Then time taken by the particle to move from position of equilibrium to maximum displacement is

A

0.5 sec

B

1.0 sec

C

2.0 sec

D

3.0 sec

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 77

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Which of the following is not a scalar quantity

A

Time

B

Mass

C

Volume

D

acceleration

View Solution

ISRO Scientist or Engineer Mechanical 2007 - Question 78

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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 acrossthreads. .
4. Torsional shear stresses in threads due tofrictional resistance.
Select the correct answer using the codes given below Codes:

A

1, 2 and 3

B

1, 3 and 4

C

2, 3 and 4

D

1, 2 and 4

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ISRO Scientist or Engineer Mechanical 2007 - Question 79

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A thin copper wire at $$300^\circ$$ is suddenly immersed in water at $$30^\circ C$$. It cools down to $$150^\circ C$$ in 70 seconds. It is then reheated to the initial temperature of $$300^\circ C$$ and suddenly exposedto air at $$30^\circ C$$ where it cools downto $$150^\circ C$$ in 200 seconds. This difference in cooling time is due to

A

Larger specific heat of water

B

Larger heat transfer coefficient in water

C

Smaller heat transfer coefficient in water

D

None of the above

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ISRO Scientist or Engineer Mechanical 2007 - Question 80

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The heat flow rate through parallel walls of thickness $$L_1, L_2$$ and $$L_3$$, having surface areas $$A_1, A_2$$ and $$A_3$$, thermal conductivities $$k_1, k_2$$ and $$k_3$$,
respectively, with the first and last walls maintained at temperatures $$t_1$$ and $$t_2$$ will be

A

$$\frac{t_1 - t_2}{\frac{L_1}{A_1k_1} + \frac{L_2}{A_2k_2} + \frac{L_3}{A_3k_3}}$$

B

$$\frac{t_1 - t_2}{\frac{k_1}{A_1L_1} + \frac{k_2}{A_2L_2} + \frac{k_3}{A_3L_3}}$$

C

$$\frac{t_1 - t_2}{\frac{k_1A_1}{L_1} + \frac{k_2A_2}{L_2} + \frac{k_3A_3}{L_3}}$$

D

$$\frac{t_1 - t_2}{\frac{L_1A_1}{k_1} + \frac{L_2}{k_2} + \frac{L_3}{k_3}}$$

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