O Level Science Notes Archives - Page 27 of 33 - Free ZIMSEC & Cambridge Revision Notes

The Alternating Current generator

By garikaib|2022-09-15T12:38:36+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

A simple AC generator. Image credit electronics-tutorials.ws ZIMSEC O Level Combined Science Notes: The Alternating Power generator

In an Alternating Current (AC) generator the current changes direction as the coil turns
An AC generator is made up a rectangular coil that rotates between the […]

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Investigating whether thick beams support more weight

By garikaib|2022-09-15T12:38:27+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Plasticine can be used to model cylinder beams. Image credit wordpress.com ZIMSEC O Level Combined Science Notes: Experiment: Investigating whether thick beams support more weight

Aim: To show that thicker beams can support more weight

Materials: Plasticine/Stikistuff, wooden board, small cardboard cylinders 2cm in […]

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Experiment:To compare the effects of atmospheric corrosion on metals

By garikaib|2022-09-15T12:38:20+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Rusted metal. Image credit racingstrong.com ZIMSEC O Level Combined Science Notes: Experiment:To compare the effects of atmospheric corrosion on metals

Aim: To compare the effects of atmospheric corrosion on various metals

Materials: samples of mild steel/cast iron, stainless steel, cutting steel (razor blade/old hacksaw blade), brass, aluminium, copper, plastic […]

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Machines: Wheel and axle

By garikaib|2022-09-15T12:38:12+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

A wheel and axle. Image credit MediaWiki ZIMSEC O Level Combined Science Notes: Machines: Wheel and axle

The wheel and axle operate on a principle similar to that of gears
A wheel is attached to an axle so that the two parts rotate together […]

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Experiment: Testing tooth cleaning agent

By garikaib|2022-09-15T12:38:05+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Colgate toothpaste ZIMSEC O Level Combined Science Notes: Experiment: Testing tooth cleaning agent

Aim: To test the properties of teeth cleaning agents

Materials: various brands of toothpaste, pH paper, microscopes, slat, bicarbonate of soda, lid bottles/suitable containers for the toothpaste

Method

Examine toothpaste under a microscope to compare the particle size of the various […]

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The menstrual cycle

By garikaib|2022-09-15T12:37:54+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Image credit lifestylechallenge.deborahgabriel.com ZIMSEC O Level Combined Science Notes: The menstrual cycle

The reproductive cycle in females is called the menstrual/estrus cycle
It has an average of 28 days
It varies from individual to individual but it follows a set pattern
The cycle is regulated by hormones produced […]

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Waste disposal

By garikaib|2022-09-15T12:37:48+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Waste disposal in Harare. Image credit thezimbabwedaily.com ZIMSEC O Level Combined Science Notes: Waste disposal

Several terms are used when dealing with waste
Sewage-is the name given to human excrement (faeces and urine) when collected together.
Sewage also includes kitchen waste and industrial waste

[…]

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Alimentary Systems

By garikaib|2022-09-15T12:41:50+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

The human digestive system. Image credit airurbano.com ZIMSEC O Level Combined Science Notes: Alimentary Systems

Unlike plants, animals are just consumers and cannot make their own food.
They rely on plans as producers.
Most of the food eaten is made up of large insoluble molecules which […]

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Experiment: Is energy released by germinating seeds?

By garikaib|2022-09-15T12:41:43+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Germinating seeds. Image credit hummert.com ZIMSEC O Level Combined Science Notes: Experiment: Is energy released by germinating seeds?

Aim: Determine whether energy is released when seeds are germinating.

Hypothesis: Seeds are structures produced by plants (living organisms). They respire when they are germinating.

Materials: tow insulated containers/vacuum flasks, two supporting […]

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The circulatory system of mammals

By garikaib|2022-09-15T12:40:37+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

The main parts of the human circulatory system. Image credit organsofthebody.com ZIMSEC O Level Combined Science Notes: The circulatory system of mammals

Mammals also have a transport system just like plants
With this transport system things like food, oxygen,water and other substances […]

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January 2023