JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech IV Year DESIGN OF AGRICULTURAL MACHINERY Previous Question Paper (May - 2019 - R15)

Write the classifications of machine design.

Calculate the force required to punch a circular blank of 60 mm diameter in a plate of 5 mm thick. The ultimate shear stress of the plate is 350 N/mm².

Define tolerance and write the methods of assigning tolerance.

Define spring index and write the various important application of springs.

Define shaft and classify the types of shafts.

What is the necessity of coupling and write the types of shaft couplings.

Define maximum fluctuation of energy and coefficient of fluctuation of speed.

Explain the relation between bearing characteristic number (ZN/p) and coefficient of friction in bearings.

Write the differences between seed drill and planter.

Write about care and maintenance of sprayers.

Explain about stress strain diagram of mild steel with a neat sketch.

A load on bolts consists of an axial pull of 10 kN together transverse shear force of 5kN. Find the diameter of the bolt required according to i) Maximum principle stress theory ii) Maximum shear stress theory and. Take Permissible tensile stress at elastic limit is 100 MPa and Poisson’s ratio is 0.3.

A thin steel tyre is shrunk on to a locomotive wheel of 1.2 m diameter. Find the internal diameter of the tyre if after shrinking on, the hoop stress in the tyre is 100 MPa. Assume E = 200 kN/mm². Find also the least temperature to which the tyre must be heated above that of the wheel before it could be slipped on. The coefficient of linear expansion for the tyre is 6.5 × 10^-6 per °C.

Define impact stress and derive an equation for impact stress on a bar.

Write the design procedure of hand level with a neat sketch.

Design a knuckle joint to transmit 150 kN. The design stress may be taken as 75MPa in tension, 60MPa in shear and 150MPa in compression.

Explain about construction and working of leaf spring with a neat sketch.

Define fits and explain about type of fits with suitable diagrams.

Derive the equations for equivalent twisting and bending moments, if shafts are subjected to axial loads in addition to combined torsion and bending loads.

A hallow shaft of 0.5 m outside diameter and 0.3m inside diameter is used to drive a propeller of a marine vessel. The shaft is mounted on bearings 6 m apart and it transmits 5600 kW at 150 r.p.m. The maximum axial propeller thrust is 500 kN and the shaft weighs 70 kN. Determine i) The maximum shear stress developed in the shaft and ii) The angular twist between the bearings.

Write the design procedure of Sleeve or Muff-coupling with suitable diagrams.

Design a rectangular key for a shaft of 50 mm diameter. The shearing and crushing stresses for the key material are 42 MPa and 70MPa. Take the width and thickness of the key of 50 mm diameter shaft is 16 and 10 mm respectively.

Write about types of rolling contact bearings with suitable diagrams.

The intercepted areas between the output torque curve and the mean resistance line of a turning moment diagram for a multi cylinder engine, take in order from one end are as follows: -35,+410, -285, +325, -335, +260, -365, +285, -260 mm². The diagram has been drawn to a scale of 1 mm = 100 N-m and 1 mm = 5°. The engine speed is 900 rpm and the fluctuation in speed not to exceed 3% of the mean speed. Find the mass and cross-section of the flywheel rim having 650 mm mean diameter. The density of the material of the flywheel may be taken as 7200 kg/m³. The rim is rectangular with the width 2 times the thickness.

Write the advantages of rolling contact bearings over sliding contact bearings and explain about reliability of bearing.

A full journal bearing of 50 mm diameter and 100 mm long has a bearing pressure of 1.4 N/mm². The speed of the journal is 900 r.p.m. and the ratio of journal diameter to the diametral clearance is 1000. The bearing is lubricated with oil whose absolute viscosity at the operating temperature of 75°C may be taken as 0.011 kg/ms. The room temperature is 35°C. Find i) The amount of artificial cooling required, ii) The mass of the lubricating oil required, if the difference between the outlet and inlet temperature of the oil is 10°C. Take specific heat of the oil as 1850 J/kg/°C.

Write the design procedure of rotavator suitable for 30 hp tractor.

A field crop power sprayer with horizontal boom having 20 × 40cm is used for spraying insecticide at a forward speed of 4.5 km/hr. Determine the actual field capacity of sprayer if its field efficiency is 80%. Also determine nozzle discharge of the sprayer if insecticide application is 1000 l/ha.

Explain the design procedure of 13 times cultivator suitable for 35 hp tractor.

Maximum yield of maize is obtained with a population of 35,000 plants per hectare. The rows are 130 cm apart and an average emergence of 90% is expected. Find (i) How many seeds per hill should be planted if hills are 130 cm apart? (ii) What would be seed spacing if the crop is drilled.