NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF AGRICULTURAL SCIENCE
JUNE/JULY 2013 EXAMINATION

COURSE CODE: AGM314

COURSE TITLE: INTRODUCTION TO FARM MECHANIZATION (2 Units).

TIME ALLOWED: 2 HOURS   

INSTRUCTION: ANSWER FOUR (4) QUESTIONS (25Marks each)

1a.What is a basic machine? Give 4 example of basic machine.

1b. A mass of 35kg is to be lifted by a wheel and axle system. The ratio of wheel to radius of axle is 5:1 Given that the system is 84% efficient; determine the effort required to lift the body. Take g = 10m/s2.

1c. List 5 workshop hand tools

2a. Describe briefly these terms use in engine.

Clearance volume

Bottom dead centre

Bore

Stroke

Swept volume

Engine capacity

Engine size

2b. what is the Cycles of Operation of an engine?

3. Describe the principles of 4-stroke Petrol Engine.

4a. Describe in brief these primary tillage equipments.

Mould board

Disc

Chisel

Sub-soiler

4b. The pulley on a machine is 230mm diameter. It is to be driven at 183rev/min. A of insectide so that wastage that could arise as a result of excessive application is avoided.

5a. describe how power is transmitted by a belt.

5b. A flat leather belt is 70mm wide and 7mm thick. Given that the safe tension per

cm of width of the belt is 140N and the belt is used in driving a 360mm pulley at 300rev/min.

Determine:

i. the allowable tension

ii. the driving tension

iii. the power transmitted by the belt.

6a. Explain the operation of a Thresher.

6b. Give a short description of a mist blower and its function.

6c. what use are the following materials in farm workshop: Rubber, mortar, reinforced concrete and paints?