NAMIBIA UNIVERSITYOF SCIENCE AND TECHNOLOGY

FACULTY OF NATURAL RESOURCESANDSPATIAL SCIENCEDEPARTMENT OF AGRICULTURE AND NATURAL RESOURCESSCIENCES

QUALIFICATION: BACHELOR OF AGRICULTURE

QUALIFICATION CODE: 07BAGR LEVEL: 5

COURSE CODE: AMC520S COURSE NAME: AGRICULTURAL MECHANISATION

SESSION: 30 MAY 2018 at 18:00 PAPER: THEORY

DURATION: 3 (THREE) hours MARKS: 150

FIRST OPPORTUNITY EXAMINATION QUESTION PAPER

EXAMINER(S) |Mr C.Els

MoperaToRr: | Mr W.F. Adank

INSTRUCTIONS 1. Answer ALL the questions.

2. Write clearly and neatly.

PERMISSIBLE MATERIALS

1.

2.

3.

THIS QUESTION PAPER CONSISTSOF 5 (FIVE) PAGES(/ncluding this front page)

SECTION A: WELDING

QUESTION 1:

Namefifteen (15) notes on safety, regarding the use of arc welding machines. (15)

QUESTION2:

Namefour(4) results when making use of a too low current during welding. (4)

QUESTION3:

Namethree results whenusing a too slow travel speed during welding. (3)

QUESTION 4:

Namefour(4) factors that influences the size of a fillet weld. (4)

SUB TOTAL:[26]

SECTION B: WATER PUMPS FOR ARTIFICIAL WATER POINTS

QUESTION1:

Nameeight (8) reasons why your pump operateswell, but the water supply is weak or non-

existent. (8)

QUESTION2:

Whatis the minimum depththat a black polyethylene pipe must be buried to protectit from

being damaged by porcupines? (1)

QUESTION3:

Whatis the maximum volumeof water that can be withdrawn from a borehole? (1)

QUESTION4:

Nameten (10) checks that must be done before starting your diesel engine (air-cooled) for

pumping water. (10)

QUESTION5:

Namesix (6) causes why an engine might notstart. (6)

SUB TOTAL:[26]

SECTION C: FENCING

QUESTION1:

What term is used to measure the energy output of an energizer? (1)

QUESTION2:

Describe four (4) ways of securing netting to the ground. (4)

QUESTION3:

Namefive (5) components which an electric fence consists of. (5)

QUESTION4:

Nameten (10) requirements of a good fence. (10)

QUESTION5:

Whatare the maximum distances allowed betweenthe following?

a. Posts on loose sand

b. Standards on loose sand

c. Posts on claysoil

d. Either standardsorline posts, on anysoil, if a jackal proof fence is being erected

e. Standards on clay soil (5)

SUB TOTAL:[25]

SECTION D: ALTERNATIVE ENERGY

QUESTION1:

Nameseven (7) aspects of importance to adhere to when obtaining a warm watersolar

system. (7)

QUESTION2:

Give one word for the following:

a. The amountof sunlight reaching an area.

b. A device that converts electricity from DC to AC current.

c. Any numberof photovoltaic modules connected electrically to provide a single D C

electrical output.

d. Ameasureofsolar radiation as heat.

e. The amountof electricity produced by a solar generator at noon onasunny day. (5)

QUESTION3:

How can one prevent damage to your watersolar system, caused by freezing in the colder

climatic regions of the country? (4)

QUESTION 4:

In the maintenance of a solar heating system, certain items must be checked on a regular

base. Name four of them and indicate for what defects they are to be checked. (8)

SUB TOTAL:[24]

SECTION E: CONCRETE

QUESTION1:

Nameseven (7) aspects that influence the strength of concrete. (7)

QUESTION2:

Namesix (6) curing methodsof concrete. (6)

QUESTION3:

Give a definition of the term curing. (5)

QUESTION4:

How will proper compacted concrete compareto poorly compacted concrete, in which 5 %

air still occurs? (1)

SUB TOTAL:[19]

SECTION F: SAFETY

QUESTION1:

Describe three (3) aspects of importance, concerningthejoint, in preparation for

soldering. (3)

QUESTION2:

Namenine(9) safety precautions to be taken when working with an angle grinder. (9)

QUESTION3:

Namefour(4) requirements of a properly solderedjoint. (4)

SUB TOTAL:[16]

SECTION G: MOTORVEHICLE

QUESTION1:

Explain in correct sequence what happens whentheignition key is turned, through the

starting process,till the key is released and the engineis running. (6)

QUESTION2:

Explain, in sequence, the working of drum brakes. (7)

QUESTION3:

Whatis the function of the valve springs? (1)

SUB TOTAL: [14]

TOTAL OF PAPER:[150]