O Level Science Notes Archives - Page 4 of 33 - Free ZIMSEC & Cambridge Revision Notes

Types of fuel

By garikaib|2025-02-12T09:01:00+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Engen Garage. Image credit chronicle.co.zw ZIMSEC O Level Combined Science Notes: Types of fuel

A fuel is any type of material that can be made to react (commonly with oxygen) and release energy in the process
Fuel provides energy to a body/machine to do work
Fuels […]

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The Diesel engine

By garikaib|2025-02-12T09:14:58+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Honda Diesel Engine. Image credit forum.cardekho.com ZIMSEC O Level Combined Science Notes: The Diesel engine

Operates in almost the same way as the Petrol Engine apart from certain differences:
They use diesel instead of Petrol
Have no spark plugs
Have a fuel injector instead […]

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Electric Power equations and calculations
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Electric Power equations and calculations

Notes, O Level Science Notes, Ordinary Level Notes

Electric Power equations and calculations

By garikaib|2025-02-12T09:31:32+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Electric Power equations and calculations

Power calculations that you are going to be presented with in the exam are varied
They all depend on your knowing:
The equation to calculate whatever variable that you are required to calculate
Your ability to substitute and change the subject of the formula to suit your needs

[…]

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The Alternating Current generator

By garikaib|2025-02-12T09:46:08+02:00February 12th, 2025|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|2025-02-12T09:10:29+02:00February 12th, 2025|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|2025-02-12T09:26:53+02:00February 12th, 2025|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|2025-02-12T08:56:05+02:00February 12th, 2025|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|2025-02-12T09:17:52+02:00February 12th, 2025|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|2025-02-12T09:34:10+02:00February 12th, 2025|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|2025-02-12T09:01:40+02:00February 12th, 2025|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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February 2025