ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 1

Report

Carnot Cycle consists of

A

Two constant pressure and two isentropic processes

B

One constant isenthalpic, one constant volume and two constant pressure processes

C

Two isothermal and two isentropic processes

D

One constant pressure, one constant volume and two isothermal processes

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 2

Report

One reversible heat engine operates between $$1600^\circ$$K and $$T_{2}^\circ$$K and another reversible heat engine operates between $$T_{2}^\circ$$K and $$400^\circ$$K. If both the engines have the same heat input and output, then temperature $$T_{2}^\circ$$ is equal to

A

800 K

B

1600 K

C

1200 K

D

6400 K

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 3

Report

Isentropic flow is

A

Reversible adiabatic flow

B

Irreversible adiabatic flow

C

Frictionless fluid flow

D

Reversible isothermal flow

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 4

Report

Reversed Joule cycle is known as

A

Rankine cycle

B

Carnot cycle

C

Bell-Coleman cycle

D

Otto cycle

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 5

Report

The thermal efficiency of Gas turbine plant is

A

$$r^{\gamma -1}$$

B

$$1 - r^{\gamma -1}$$

C

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

D

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

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 6

Report

A 100 W electric bulb was switched on in a $$2.5 m \times 3m \times 3 m$$ size thermally insulated room having temperature of $$20^\circ$$C. The room temperature at the end of 24 hrs. will be

A

$$100^\circ$$C

B

$$470^\circ$$C

C

$$370^\circ$$C

D

$$600^\circ$$C

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 7

Report

A solar energy based heat engine which receives 80 kJ of heat at $$100^\circ$$C and rejects 70 kJ of heat to the ambient at $$30^\circ$$C is to be designed. The thermal efficiency of heat engine is

A

70%

B

18.8%

C

12.5%

D

cannot be calculated

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 8

Report

A mixure of gases expand from $$0.03 m^{3} to 0.06 m^{3}$$ at constant pressure of 1 MPA and absorb 84 kJ of heat during the process. The change in internal energy of the mixture is

A

54 kJ

B

30 kJ

C

84 kJ

D

110 kJ

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 9

Report

If the concentrated load applied at the free end of a cantilever beam is doubled along with its length and moment of inertia also, then the deflection at free end will increase by

A

2 times

B

4 times

C

8 times

D

12 times

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 10

Report

In the case of a beam simply supported at both ends, if the same load instead of being concentrated at centre is distributed uniformly throughout the length, then deflection at
centre will get reduced by

A

$$\frac{1}{2}$$ times

B

$$\frac{1}{4}$$ time

C

$$\frac{5}{8}$$ time

D

$$\frac{3}{8}$$ time

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 11

Report

If the Bending moment is increased three times, then to keep the stress in the beam same, sectional modulus shall be

A

decreased 3 times

B

increased 3 times

C

unchanged

D

increased 6 times

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 12

Report

A beam with rectangular section of $$120 mm \times 40 mm$$ is placed horizontally by mistake, (with width as 120 mm and depth as 40 mm) whereas it was designed to be placed vertically. (with width as 40 mm and depth as 120 mm). The ratio of section modulus will be

A

$$\frac{1}{3}$$

B

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

C

$$\frac{1}{6}$$

D

$$\frac{1}{8}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 13

Report

If a shaft is required to transmit twice the power at twice the speed for which it is designed, its diameter must

A

increase two times

B

reduce two times

C

remain same

D

increase three times

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 14

Report

The strength of a hollow shaft in comparison to solid shaft, both having outer diameter D and inner diameter of hollow shaft as $$\frac{D}{2}$$

A

Half

B

$$\frac{7}{8}1^{th}$$

C

$$\frac{15}{16}$$ times

D

Remain same

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 15

Report

Steel bar of $$40 mm \times 40 mm$$ square section is subjected to an axial compressive load of 200 kN. If the length of the bar is 2 m and E (Youngs modulus) = 200 GPa. The elongation of bar will be

A

5.4 mm

B

1.25 mm

C

2.7 mm

D

3.4 mm

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 16

Report

The shear force diagram for a simply supported beam carrying uniformly distributed load of w per unit length, consists of

A

One right angled triangle

B

One equilateral triangle

C

Two right angled triangle

D

Two rectangles

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 17

Report

The power transmitted by a shaft 60 mm diameter at 180 RPM, if the permissible stress is $$85 N/mm^{2}$$

A

68 kW

B

650 KW

C

1200 kW

D

7 KW

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 18

Report

A material has a young’s modulus of $$1.25 \times 10^{5}$$ $$\frac{N}{mm^{2}}$$ and a poisson’s ratio of 0.25. The bulk modulus of the material will be

A

$$83 \times 10^{5}$$ $$\frac{N}{mm^{2}}$$

B

$$0.83 \times 10^{5}$$ $$\frac{N}{mm^{2}}$$

C

$$8.3 \times 10^{3}$$ $$\frac{N}{mm^{2}}$$

D

$$8.3 \times 10^{5}$$ $$\frac{N}{mm^{2}}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 19

Report

Neutral solution is one which has pH value

A

Greater than 7

B

Equal to 7

C

Less than 7

D

None of the above

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 20

Report

Forced feed lubrication system means that oil is delivered to the engine by

A

Gravity

B

Pressure created by oil pump

C

Splashing of the crank shaft

D

None of the above

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 21

Report

The purpose of thermostat in an engine cooling system is to

A

Indicate coolant temperature

B

Prevent coolant from boiling

C

Allow the engine to warm up quickly

D

Pressurize coolant for effective cooling

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 22

Report

In a boiler, feed water supplied per hour is 205 kg while coal fired per hour is 23 kg. The net enthalpy rise per kg of water is 145 kj. If the calorific value of coal is 2050 $$\frac{kj}{KGg}$$, then boiler efficiency will be

A

56%

B

75%

C

48%

D

63%

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 23

Report

A throttle governed steam engine develops 15 kW with 280 kg power of steam and 35 kW with 520 kg per hour of steam. The steam consumption in kg per hour when developing 20 kW of power will be nearly

A

340 $$\frac{kg}{hr}$$

B

150 $$\frac{kg}{hr}$$

C

cannot be calculated

D

280 $$\frac{kg}{hr}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 24

Report

A fluid which obeys Newton’s law of viscosity is termed as

A

Real fluid

B

Newtonian fluid

C

Non-Newtonian fluid

D

Ideal fluid

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 25

Report

A water tank contains 1.3 m deep water. The pressure exerted by water per metre length of tank is

A

8.29 kN

B

18.29 kN

C

28.9 kN

D

0.28 kN

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 26

Report

The gauge pressure at the surface of a liquid of density 900 $$\frac{Kg}{m^{3}}$$ is 0.4 bar. If the atmospheric pressure is $$1 \times 10^{5}pa$$ the absolute pressure at a depth of 50 M is

A

5.81 bar

B

15.8 bar

C

25.8 bar

D

0.5 bar

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 27

Report

In Hydro-Electric plants, power transmitted through pipe is maximum when the head lost due to friction is

A

One fourth of the total supply head

B

One half of the total supply head

C

One third of the total supply head

D

Two third of the total supply head

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 28

Report

Reynolds number is ratio of Inertial forces to

A

Elastic force

B

Surface tension

C

Critical velocity

D

Viscous force

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 29

Report

A pelton wheel develops 1750 kW under a head of 100 mts while running at 200 rpm and discharging 2500 litres of water per sec. The unit power of wheel will be

A

3.75 kW

B

0.75 kW

C

1.75 kW

D

0.25 kW

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 30

Report

Power required to drive a centrifugal pump is

A

Directly proportional to speed of its impeller

B

Directly proportional to square of the speed of its impeller

C

Directly proportional to cube of the speed of its impeller

D

Inversely proportional to cube of the speed of its impeller

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 31

Report

The specific speed of a centrifugal pump delivering 810 Litres of water per sec. against head of 16 mts. at 725 RPM is

A

81 RPM

B

810 RPM

C

40 RPM

D

16 RPM

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 32

Report

A centrifugal pump delivers 1000 lts per minute at 2000 RPM against total head of 50 mts. and requires 32 BHP for its operation. If speed is reduced to 1000 RPM, the discharge and head developed will be

A

500 $$\frac{lts}{min}$$ and 25 mtr

B

500 $$\frac{lts}{min}$$ and 12.5 mtr

C

250 $$\frac{lts}{min}$$ and 12.5 mtr

D

250 $$\frac{lts}{min}$$ and 25 mtr

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 33

Report

A flow is said to be supersonic, if the

A

If the velocity of flow is very high

B

Mach number is between 1 and 6

C

Mach number is more than 6

D

If the discharge is difficult to measure

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 34

Report

Fouling factor is used in heat exchangers due to

A

Factor in case of Newtonian fluids

B

Safety factor in design

C

Due to fluid leakage

D

When liquid exchanges heat with vapour

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 35

Report

In a Counter flow heat exchanger design, fluid rates and specific heats were chosen in such a manner that heat capacities of both the fluids are same. A hot fluid enters at $$100^\circ$$ C and leaves at $$60^\circ$$C. The cold fluid enters heat exchanger at $$40^\circ C$$. The mean temperature difference between the two fluids is

A

$$40^\circ C$$

B

$$60^\circ C$$

C

$$20^\circ C$$

D

$$36.6^\circ C$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 36

Report

The unit of overall coefficient of heat transfer is:

A

$$\frac{W}{m^{2}}^\circ K$$

B

$$\frac{W}{m^{2}} K$$

C

$$\frac{W}{m}^\circ K$$

D

$$\frac{W}{m} K$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 37

Report

The heat transfer by conduction through a thick cylinder of inner radius $$r_{1}$$ ,outer radius $$r_{2}$$, Higher temperature $$T_{1}$$,lower temperature $$T_{2}$$, length of cylinder l and thermal conductivity k is given by:

A

$$ \frac{2 \pi  lk (T_{1}-T_{2})}{2.3 \log \left(\frac{r_{2}}{r_{1}}\right)}$$

B

$$\frac{2.3 \log \left(\frac{r_{2}}{r_{1}}\right)}{2 \pi lk (T_{1}-T_{2})}$$

C

$$\frac{2 \pi (T_{1}-T_{2})}{2.3  lk \log \left(\frac{r_{2}}{r_{1}}\right)}$$

D

$$ \frac{2 \pi lk}{2.3(T_{2}-T_{1}) \log \left(\frac{r_{2}}{r_{1}}\right)}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 38

Report

According to Stefan-Boltzmann law, the total radiation from black body per second per unit area is directly proportional to the

A

Absolute temperature

B

Fourth power of absolute temperature

C

Cube of the absolute temperature

D

Square of the absolute temperature

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 39

Report

In a condenser of a power plant, the steam condenses at temperature of $$60^\circ$$ C. The cooling water enters at $$30^\circ$$C and leaves at $$45^\circ$$C. The logarithmic mean temperature difference will be around

A

$$20^\circ C$$

B

$$80^\circ C$$

C

$$200^\circ C$$

D

$$5^\circ C$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 40

Report

In shell and tube heat exchanger, baffles are mainly used for

A

Increase the mixing of fluid

B

Direct the flow in desired direction

C

Reduce fouling of the tube surface

D

Increase the heat transfer area

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 41

Report

For a glass plate, transitivity and reflectivity are specified as 0.86 and 0.08 respectively, the absorptivity of the glass plate is

A

0.86

B

0.06

C

0.08

D

1.00

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 42

Report

A composite slab has two layers of different materials with thermal conductivities $$k_{1}$$ and $$k_{2}$$. If each layer has same thickness, then the equivalent thermal conductivity will be:

A

$$K_{1} K_{2}$$

B

$$K_{1} + K_{2}$$

C

2$$\frac{K_{1} K_{2}}{(K_{1} + K_{2})}$$

D

$$\frac{K_{1} + K_{2}}{(K_{1} K_{2})}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 43

Report

The ratio of heat flow $$\frac{Q_{1}}{Q_{2}}$$ from two walls of same thickness having their thermal conductivities as $$K_{1} = 2K_{2}$$ will be:

A

1

B

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

C

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

D

2

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 44

Report

In case of saddle key, power is transmitted by means of

A

Friction force

B

Shear resistance of key

C

Torsional resistance of key

D

Tensile force

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 45

Report

The angle of twist for a transmission shaft is inversely proportional to

A

$$Shaft  diameter$$

B

$$(shaft  diameter)^{2}$$

C

$$(shaft  diameter)^{3}$$

D

$$(shaft  diameter)^{4}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 46

Report

Two mating spur gears have 40 and 120 teeth respectively. The pinion transmits at 1200 rpm and transmits a torque of 20 N-m. The torque transmitted by gear is:

A

60 N-m

B

6.6 N-m

C

40 N-m

D

66 N-m

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 47

Report

The expected life of a ball bearing subjected to a load of 9800 N and operating at 1000 RPM is 3000 hrs. What is the expected life of the same bearing for similar load of 4900 N and speed of 2000 RPM

A

12000 hrs.

B

Remain same

C

6000 hrs.

D

1500 hrs.

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 48

Report

Neutral axis of a beam is;

A

Layer subjected to tensile stress

B

Layer subjected to compressive stress

C

Layer subjected to torsion stress

D

Layer subjected to zero stress

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 49

Report

A Gas engine has a swept volume of $$300 cm^{3}$$ and its volumetric efficiency is 0.88 and mechanical efficiency is 0.90. The volume of mixture taken in per stroke is

A

$$248 cm^{3}$$

B

$$252 cm^{3}$$

C

$$264 cm^{3}$$

D

$$286 cm^{3}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 50

Report

The ratio of the brake power to indicated power is called

A

Overall efficiency

B

Thermal efficiency

C

Mechanical efficiency

D

Volumetric efficiency

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 51

Report

A heat engine is supplied with 250 $$\frac{KJ}{s}$$ of heat at a constant fixed temperature of $$227^\circ$$C. The heat is rejected at $$27^\circ$$C. If the cycle is reversible, the amount of heat rejected is :

A

150 $$\frac{KJ}{s}$$

B

200 $$\frac{KJ}{s}$$

C

273 $$\frac{KJ}{s}$$

D

185 $$\frac{KJ}{s}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 52

Report

A heat Engine gives an output of 3 kW when the input is 10000 $$\frac{joules}{sec}$$. The thermal efficiency of the engine is

A

30%

B

20%

C

40%

D

76.7%

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 53

Report

A base load power station of capacity 35 MW has annual output of $$150 \times 10^{6}$$ kWh. The plant capacity factor of the power plant is

A

68%

B

35%

C

49%

D

25%

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 54

Report

Diesel engine having brake thermal efficiency of 30% and the calorific value of fuel used is 10000 $$\frac{kcal}{kg}$$, the brake specific fuel consumption will be

A

0.21 $$\frac{kg}{HP.hr}$$

B

0.29 $$\frac{kg}{HP.hr}$$

C

0.39 $$\frac{kg}{HP.hr}$$

D

0.49 $$\frac{kg}{HP.hr}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 55

Report

The control rods in the control system of nuclear reactors are used to

A

Control fuel consumption

B

Absorb excess neutrons

C

Control temperature

D

None of the above

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 56

Report

Efficiency of Carnot engine is 80%. If the cycle direction is reversed, what will be the value of COP of reversed Carnot cycle

A

0.25

B

0.5

C

1.25

D

1.5

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 57

Report

If the evaporator temperature of a refrigeration plant is lowered, keeping condensing temperature constant, the horse power requirement of compressor will

A

Remain same

B

Increase

C

Decrease

D

More or less depending on capacity

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 58

Report

For Ammonia refrigeration system, the pipe for carrying refrigerant shall be made of following material:

A

brass

B

copper

C

steel or wrought iron

D

aluminium

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 59

Report

In psychrometric chart, relative humidity lines are:

A

curved

B

horizontal

C

straight inclined from left to right

D

vertical

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 60

Report

The operating temperature of a cold storage is $$-9^\circ$$C and load for the refrigeration plant is 20 kW for ambient temperature of $$24^\circ$$C. The actual COP of the plant used is one fourth that of ideal plant working between the same temperatures. The power required to drive the plant is:

A

2.5 kW

B

5 kW

C

10 kW

D

3 kW

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 61

Report

The formation of frost on cooling coils in a refrigerator

A

Increases heat transfer

B

Improves COP of the system

C

Reduces power consumption

D

Increases power consumption

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 62

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The effect of Sub cooling in a refrigeration cycle will result in

A

More COP

B

Less COP

C

No change in COP

D

More power consumption

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 63

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In order to cool and dehumidify a stream of moist air, it must be passed over the coil at a temperature

A

Which lies between dry bulb and wet bulb temperature of incoming stream

B

Which lies between wet bulb and dew point temperature of incoming stream

C

Which is equal to wet bulb temperature of air

D

Which is lower than dew point temperature of air

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 64

Report

In a chemical dehumidification process, the dry bulb temperature of air

A

Decreases

B

Remains constant

C

Increases

D

Depends on wet bulb temperature

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 65

Report

The atmospheric air at dry bulb temperature of $$15^\circ$$C enters a heating coil maintained at $$40^\circ$$C. The air leaves the heating coil at $$25^\circ$$C. The by-pass factor of the heating coil is

A

0.376

B

0.6

C

0.4

D

0.5

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 66

Report

A grinding wheel of 150 mm diameter is rotating at 3000 rpm. The grinding speed is :

A

$$15 \pi \frac{m}{s}$$

B

$$7.5 \pi \frac{m}{s}$$

C

$$45 \pi \frac{m}{s}$$

D

$$450 \pi \frac{m}{s}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 67

Report

The angle made by the face of the tool and the plane parallel to the base of cutting tool is called

A

Rake angle

B

Cutting angle

C

Lip angle

D

Clearance angle

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 68

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When the metal is removed by erosion caused by rapidly recurring spark discharges between the tool and work, the process is known as

A

Electro chemical machining

B

Ultra-sonic machining

C

Electro-discharge machining

D

Electro-static machining

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 69

Report

In order to double the period of a simple pendulum, the length of the string should be :

A

Halved

B

Doubled

C

Tripled

D

Quadrupled

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 70

Report

In a multiple V-belt drive system, when a single belt is damaged, it is preferable to change the complete set in order to

A

reduce vibration

B

reduce slip

C

ensure proper alignment

D

ensure uniform loading

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 71

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Mohan is five times older than his son. After 4 years the sum of their ages will be 44 years. Find the present age of Mohan?

A

42 years

B

30 years

C

25 years

D

40 years

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 72

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For a sphere of radius 10 cm, the numerical value of surface area is what percent of numerical value of its volume?

A

40

B

25

C

12.5

D

30

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 73

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A man bought a house and a cart. If he sells the house at 10% loss and cart at 20% gain, he will not lose anything. But, if he sells the house at 5% loss and cart at 5% gain he would lose Rs.100. The amount paid by him for the house and cart will be?

A

Rs.2000 and Rs.4000

B

Rs. 400 and Rs. 200

C

Rs. 200 and Rs.400

D

Rs. 4000 and Rs. 2000

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 74

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Average marks of 15 students in a class is 145, maximum marks being 150. If two lowest scores are removed, the average increases by 5. Also two lowest scores are consecutive
multiples of 9. What is the lowest score in the class?

A

126

B

108

C

117

D

None of the above

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 75

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In a mixture of wheat and barley, wheat is 60% of 400 kg of mixture. Further, some quantity of barley is added and percentage of wheat becomes 53 $$\frac{1}{3}$$ % .How many kg of barley is added?

A

25

B

50

C

80

D

40

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 76

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I see an object 3 kms to east and 4 kms to north. It appears to be moving at 1 km per minute in south west direction. At what speed (km per minute) is it getting closer to me?

A

$$\frac{1}{5\sqrt{2}}$$

B

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

C

$$\frac{7}{5\sqrt{2}}$$

D

$$\frac{7}{5}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 77

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Eigen values of a $$4 \times 4$$ matrix [A] are given as 2, -3, 13 and 7. Then, what is the value of
$$\mid det[A] \mid$$?

A

25

B

13

C

-546

D

546

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 78

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The mean value of a function f(x) from point ‘a’ to point ‘b’ is given by

A

$$\frac{f(a)+f(b)}{2}$$

B

$$\frac{f(a)+2f(\frac{a+b}{2})+f{b}}{4}$$

C

$$\int_{a}^{b} f(x) dx$$

D

$$\frac{\int_{a}^{b} f(x) dx}{b-a}$$

View Solution

ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 79

Report

The area of a circle of radius ‘a’ can be found by following integral

A

$$\int_{a}^{b} (a^{2}+x^{2}) dx$$

B

$$\int_{0}^{2 \pi} \sqrt{(a^{2}-x^{2})} dx$$

C

$$4 \times \int_{0}^{a} \sqrt{(a^{2}-x^{2})} dx$$

D

$$\int_{0}^{a} \sqrt{(a^{2}-x^{2})} dx$$

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ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018 - Question 80

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In a box there are 5 red balls, 3 blue balls and 2 green balls. If a ball is selected at random what is the probability that it is blue or green?

A

$$\frac{2}{5}$$

B

$$\frac{1}{3}$$

C

$$\frac{9}{10}$$

D

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

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