Appropriate technology is technology which finds inexpensive solutions to the needs of developing countries. It is especially useful in poor areas a long way from towns and cities. In these areas, it uses local materials and local skills. One example of appropriate technology is the wind pump. It is simple to construct and maintain, and does not need fuel. It contains a simple mechanism, a crankshaft. The crankshaft converts the rotary movement of the blades into an up-and-down movement – this moves the pump’s piston up and down.
The clockwork radio is another example. It consists of a clockwork motor which drives a small generator. The step-up gears increase the speed of the motor, and the generator produces enough
electricity for the radio. The clockwork computer uses the same form of power. Its cost is low because the computer is not advertised, and it uses free software (unlike Microsoft software, for example, which users must pay for).
Unlike a clockwork generator, most portable generators have an engine to drive them. These generators are used in emergencies or in places without electricity. They use fuel to generate electricity for lighting, for example. Portable generators often use the simple two-stroke engines. They can also use four stroke engines, like car engines.
In a four-stroke petrol engine there is a cycle which is completed in four strokes (or movements) of the piston. On the first stroke, fuel and air are sucked into the cylinder. The second stroke is called the compression stroke: the piston moves up and compresses the air and fuel in the cylinder. The compressed fuel is ignited by the spark plug. On the third stroke, the gas from the burning fuel expands and pushes the piston down the cylinder. That is called the combustion stroke or power stroke. On the fourth stroke, the exhaust stroke, the rising piston pushes the exhaust gas out of the engine.
In the two-stroke cycle, power/combustion and exhaust are combined in one stroke, compression and ignition in the other stroke. This simplifies construction and reduces the cost of two-stroke engines. However, they are noisy and produce more pollution than four-stroke engines.
Match the words listed under ‘A’ to their contextual meanings presented under ‘B’.
Words taken form the passage
Meanings of the words as they are used in the passages you have just read
portable (passage 1, paragraph 3, line 12)
combustion (passage 1, paragraph 4, line 20)
exhaust (passage 1, paragraph 4, line 22)
buckling (passage 2, paragraph 2, line 8)
mould (passage 2, paragraph 2, line 12)
complete
tired
mobile
burnt gas
shape
fastening
detonation
fixable
collapsing
inflammation
fungi
Answers
Answer:
Appropriate technology is technology which finds inexpensive solutions to the needs of developing countries. It is especially useful in poor areas a long way from towns and cities. In these areas, it uses local materials and local skills. One example of appropriate technology is the wind pump. It is simple to construct and maintain, and does not need fuel. It contains a simple mechanism, a crankshaft. The crankshaft converts the rotary movement of the blades into an up-and-down movement – this moves the pump’s piston up and down.
The clockwork radio is another example. It consists of a clockwork motor which drives a small generator. The step-up gears increase the speed of the motor, and the generator produces enough
electricity for the radio. The clockwork computer uses the same form of power. Its cost is low because the computer is not advertised, and it uses free software (unlike Microsoft software, for example, which users must pay for).
Unlike a clockwork generator, most portable generators have an engine to drive them. These generators are used in emergencies or in places without electricity. They use fuel to generate electricity for lighting, for example. Portable generators often use the simple two-stroke engines. They can also use four stroke engines, like car engines.
In a four-stroke petrol engine there is a cycle which is completed in four strokes (or movements) of the piston. On the first stroke, fuel and air are sucked into the cylinder. The second stroke is called the compression stroke: the piston moves up and compresses the air and fuel in the cylinder. The compressed fuel is ignited by the spark plug. On the third stroke, the gas from the burning fuel expands and pushes the piston down the cylinder. That is called the combustion stroke or power stroke. On the fourth stroke, the exhaust stroke, the rising piston pushes the exhaust gas out of the engine.
In the two-stroke cycle, power/combustion and exhaust are combined in one stroke, compression and ignition in the other stroke. This simplifies construction and reduces the cost of two-stroke engines. However, they are noisy and produce more pollution than four-stroke engines.
Match the words listed under ‘A’ to their contextual meanings presented under ‘B’.
Words taken form the passage
Meanings of the words as they are used in the passages you have just read
portable (passage 1, paragraph 3, line 12)
combustion (passage 1, paragraph 4, line 20)
exhaust (passage 1, paragraph 4, line 22)
buckling (passage 2, paragraph 2, line 8)
mould (passage 2, paragraph 2, line 12)
complete
tired
mobile
burnt gas
shape
fastening
detonation
fixable
collapsing
inflammation
fungi
Explanation:
Appropriate technology is technology which finds inexpensive solutions to the needs of developing countries. It is especially useful in poor areas a long way from towns and cities. In these areas, it uses local materials and local skills. One example of appropriate technology is the wind pump. It is simple to construct and maintain, and does not need fuel. It contains a simple mechanism, a crankshaft. The crankshaft converts the rotary movement of the blades into an up-and-down movement – this moves the pump’s piston up and down.
The clockwork radio is another example. It consists of a clockwork motor which drives a small generator. The step-up gears increase the speed of the motor, and the generator produces enough
electricity for the radio. The clockwork computer uses the same form of power. Its cost is low because the computer is not advertised, and it uses free software (unlike Microsoft software, for example, which users must pay for).
Unlike a clockwork generator, most portable generators have an engine to drive them. These generators are used in emergencies or in places without electricity. They use fuel to generate electricity for lighting, for example. Portable generators often use the simple two-stroke engines. They can also use four stroke engines, like car engines.
In a four-stroke petrol engine there is a cycle which is completed in four strokes (or movements) of the piston. On the first stroke, fuel and air are sucked into the cylinder. The second stroke is called the compression stroke: the piston moves up and compresses the air and fuel in the cylinder. The compressed fuel is ignited by the spark plug. On the third stroke, the gas from the burning fuel expands and pushes the piston down the cylinder. That is called the combustion