Len Academy Question for Basic Technology, JSS3, 2nd Term, 2020, Part 2

Which of the following is not a type of maintenance?

• A. Fixated

• B. Overhaul

• C. Predictive

• D. Reinforcement

• E. Periodic

• F. Corrective

Which of the following is incorrect concerning preventive maintenance?

• A. It is considered to be the best form of maintenance

• B. Immunization is a form of preventive maintenance

• C. Worn out parts may be discovered when preventive maintenance is carried out

• D. Preventive maintenance is defined as the repairs carried out on an equipment or object after a correct prediction of an impending fault

• E. A person who services his car monthly practices preventive maintenance (even though the car functions properly)

• F. The main goal of preventive maintenance is to stop a device from breaking down suddenly

The following statements are true concerning wood except _____.

• A. It is an inorganic material

• B. It is a structural tissue

• C. It is composed mainly of cellulose

• D. Hardwood and Softwood are types of wood

• E. It constitutes the stems and branches of trees

• F. It is porous and fibrous

Which of the following is not a characteristic of hardwood?

• A. They are more fire resistant in comparison to softwood

• B. Their stem are divided into trunks called dendritic form

• C. Birch, Teak and Alder are examples of hardwood

• D. They always have a higher density than softwood of the same mass

• E. They are suitable for making deckings in buildings

• F. Most hardwood are expensive than softwood

The outermost covering of a wood is called the _____.

• A. Wood skin

• D. Heartwood

• C. Cortex

• D. Cambium

• E. Sclerenchyma

• F. Bark

The followings are characteristics of ceramics except _____.

• A. They readily undergo oxidation

• B. They have high melting point

• C. They are durable

• D. Most are insulators but graphite is a conductor of electricity

• E. Most are non-magnetic

• F. They have great tensile strength but graphite is soft

Which of the following statement is false of ceramics?

• A. They are not metals

• B. They are not plastics

• C. Ceramics can be absolutely defined by its products characteristics

• D. Ceramic materials are not organic in nature

• E. Ceramics are refractory in nature

• F. Ceramics materials are usually made from clay

Which of the following is not a function of thin continuous line in Technical drawing?

• A. Used for representing projection lines
• B. Used as construction lines
• C. Used for representing visible outline and edges
• D. Used for representing leader lines
• E. Used as intersection lines
• F. Used as measurement lines

Rubber bands last longer when refrigerated

Lighter was invented before matches

Johann Wolfgang Dobereiner was credited with the invention of lighter in 1826 while the actual match was made 3 years later

Volkswagen group of companies own some of the top cars of the world. These are Audi, Bentley, Bugatti, Ducati, Lamborghini and Porsche

Preventive maintenance is carried out routinely on a device even though no apparent fault may be present on such device.

The goal of preventive maintenance as the name suggest is to prevent a sudden breakdown on a device or equipment.

As an instance, a person who services his or her car monthly even though the car is still able to function correctly is said to be carrying out preventive maintenance on the car.

In the course of a preventive maintenance, worn out parts may be discovered and replaced as soon as possible. Also, there may be a change of oil while other little adjustments may also be carried out.

We can even carry out preventive maintenance on our body to prevent certain diseases. For this reason, some persons have discovered cancerous cells in their body through regular medical checkup; and were able to kill such cells before they become malignant.

As a matter of fact; immunization is a form of preventive maintenance.

Please read more on Immunization here.

Please read more on maintenance and types of maintenance here

Hardwoods are derived from angiosperms. They show the following characteristics:

1. They usually have a higher density than softwood. Balsa is an exception.

2. They are usually more expensive than softwood.

3. They grow at a slower rate than softwood.

4. Hardwood trees shed their leaves in certain times of the year.

5. Hardwood are more fire resistant than softwood.

6. The leaves of hardwood trees are evergreen.

7. They are used for making quality furniture (in terms of strength). They are also suitable for decking in buildings.

8. Hardwood trees always have divided trunks which are sometimes referred to as a dendritic form.

9. In terms of price, hardwood are usually more expensive than softwood.

Examples of hardwood include iroko, ash, beech, alder, teak, birch, mahogany, maple, oak, balsa and walnut.

Please read more on hardwood vs softwood here

Ceramics are refractory. They also require a very high amount of heat and subsquent cooling to be formed.

Being refractory means that they are capable of withstanding a variety of abuses like high temperatures and chemical attacks.

Ceramics are generally made by taking clay from the ground and mixing it with water. It is then shaped into any form and fired inside an oven (called kiln) at a very high temperature. They may then be decorated with a waterproof, paint-like substances called glazes.

Please read more on ceramics here

Ceramics may have constrasting physical and chemical properties (or characteristics); but in general,

1. They have high melting points.

2. They are heat resistant.

3. They can be very hard with great strength; although a few are brittle or soft; for example, graphite.

4. They are durable (last for a long time).

5. Most are electrical insulators (cannot conduct electricity) but; graphite is an electrical conductor.

6. They are chemically unreactive or inert.

7. They are not easily oxidized.

8. Most are non-magnetic.