Sources of Power - Farm Power - Agricultural Engineering Previous Year Questions

1

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

As compared to diesel, the heating value and exhaust emissions such as \(CO\), \(CO_2\) and smoke density of biodiesel when used in compression ignition engine are

A

Lower and higher respectively

B

Higher and lower respectively

C

Lower and lower respectively

D

Higher and higher respectively

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2

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

An oil engine works on the ideal diesel cycle with a compression ratio of 18:1. The constant pressure energy addition ceases at 10% of the stroke. The intake pressure and temperature are 100 kPa and 300 K respectively. The hourly air consumption is 100 m³. If the ratio of specific heats is 1.4, the maximum temperature in the cycle is

A

953.3 K

B

1334.6 K

C

2154.5 K

D

2573.9 K

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3

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

The mechanical efficiency of a power tiller engine developing 7.5 kW is 80%. The calorific value of diesel is 45 MJ kg\(^{-1}\). If the indicated thermal efficiency is 35%, the brake specific fuel consumption of the engine is

A

0.135 kg kW\(^{-1}\)h\(^{-1}\)

B

0.228 kg kW\(^{-1}\)h\(^{-1}\)

C

0.245 kg kW\(^{-1}\)h\(^{-1}\)

D

0.286 kg kW\(^{-1}\)h\(^{-1}\)

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4

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

A solar photovoltaic system comprising solar photovoltaic array, inverter and a motor-pump unit is installed for supplying drinking water in a village. There are 24 modules in the array and each module contains 36 number of cells of size 104×104 mm with a conversion efficiency of 12.8%. The global solar radiation incident normally on the cells is 945 W m\(^{-2}\). The power consumed in lifting the water is found to be 435 W. If the pump-motor unit efficiency is 45%, the efficiency of the inverter is

A

56.21%

B

69.42%

C

80.25%

D

85.52%

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5

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

A diatomic, adiabatically compressible fluid having the molecular mass of 16 is flowing through a nozzle at a temperature of 20 °C. If the velocity of the fluid is 430 m s−1, the Mach Number is

A

0.93

B

0.97

C

1.03

D

1.07

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6

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

Instantaneous collector efficiency is

A

43.80%

B

47.40%

C

51.53%

D

55.76%

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7

2007 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2007

If mechanical agitation requires 375 W input power and the pump efficiency is 70%, the maximum power input required is

A

720 W

B

879 W

C

1095 W

D

1403 W

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8

2008 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2008

A double acting single cylinder reciprocating pump has a cylinder diameter of 150 mm and stroke 300 mm. Suction and delivery heads for the pump are 3 and 30 m respectively. If the pump delivers 0.01033 m³ s⁻¹ of water at 60 rpm, the percentage slip is

A

97.43

B

1.57

C

2.57

D

0.0257

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9

2008 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2008

A 20 kW four stroke cycle diesel engine is running at 2400 rpm and maintaining an ignition delay of 18° during combustion. When the engine speed is reduced by 23 percent, the ignition delay increases by 4°. If the specific fuel consumption is 0.20 kg kW⁻¹ h⁻¹, the percent change in the fuel consumption during the above conditions of combustion is

A

37.0

B

38.64

C

61.36

D

62.96

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10

2008 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2008

One kilogram of air is subjected to polytropic compression from a volume of 28 m3 and a pressure of 101 kPa to a volume of 2 m3 and pressure of 2 MPa. The external work required to make this compression possible is

A

1.66 MJ

B

2.93 MJ

C

3.04 MJ

D

8.92 MJ

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11

2008 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2008

A multi-crop thresher was tested utilizing power from a tractor PTO shaft and the fuel consumption recorded was 4.5 L h^-1. The brake thermal efficiency of the engine is 32 percent and density of the fuel having a heating value of 40 MJ kg^-1 is 825 kg m^-3. If the transmission loss from the engine to PTO drive is 5 percent, the power consumed by the thresher is

A

8.66 kW

B

12.54 kW

C

13.20 kW

D

41.25 kW

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12

2008 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2008

A farmer wishes to construct a 5 m³ capacity biogas plant with a cylindrical digester. The depth of the digester below the ground level is restricted to 5 m. Assume that 1.0 kg of cow dung produces 0.04 m³ of gas per day and that the bulk density of wet cow dung is 1100 kg m^-3. If equal amount of water on volume basis is added to the dung for slurry preparation and the retention period is taken as 40 days, the diameter of the digester tank will be

A

0.24 m

B

1.08 m

C

1.52 m

D

2.31 m

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13

2009 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2009

The type of gasifier which produces nearly tar free producer gas is

A

counter current gasifier

B

co-current gasifier

C

cross-draught gasifier

D

fluidized bed gasifier

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14

2009 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2009

A horizontal axis wind rotor is to be designed for a tip speed ratio of 1.5, rotor diameter 3.3 m and angle of attack (the angle at which the wind will strike the blade) 5°. If wind velocity in each part of the swept area of the rotor is reduced to one-third of its upstream wind velocity, the blade angle in degrees at the tip of the rotor will be

A

14

B

19

C

24

D

29

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15

2010 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2010

A farmer constructed a 2 m³ days HRT (hydraulic retention time) Deenbandhu model biogas plant. The gas will be solely used for cooking in a stove with a burner efficiency of 45%. If the density of biogas is 0.94 kg m^-3 with a heating value of 21 MJ kg^-1, the total effective energy available per day in MJ will be

A

17.77

B

18.91

C

24.47

D

39.48

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16

2011 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2011

An engine is to be run in dual fuel mode using diesel and producer gas with diesel as pilot fuel. Operation NOT required while running the engine is

A

cooling of the producer gas

B

cleaning of the producer gas

C

preheating of the producer gas

D

mixing of producer gas with air

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17

2011 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2011

A horizontal axis windmill having 8 blades is used for pumping water. Each blade has a tip radius of 1.0 m and a mean chord of 0.1 m. Assuming blade length equal to tip radius, solidity of the windmill is

A

0.03

B

0.10

C

0.25

D

0.80

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18

2011 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2011

The pump is driven by an electric motor. If the pump, drive and motor efficiencies are 80%, 82% and 90% respectively, the required size of electric motor in horse-power will be

A

20.0

B

24.5

C

30.0

D

33.5

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19

2011 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2011

The size of motor required for operating the pump in kW is

A

3.60

B

3.96

C

4.24

D

4.65

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20

2011 · Agricultural Engineering · Farm Power · Sources of Power

Agricultural Engineering (AG) 2011

The fuel consumed by a motorcycle during a journey while traveling at various speeds is indicated in the graph below.
The distances covered during four laps of the journey are listed in the table below

Lap	Distance (kilometres)	Average speed (kilometres per hour)
P	15	15
Q	75	45
R	40	75
S	10	10

From the given data, we can conclude that the fuel consumed per kilometre was least during the lap

A

P

B

Q

C

R

D

S

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