science

Oka (mass)

Oka (mass) is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Oka (mass) rather than just read about it. In short: The oka, okka, or oke (Ottoman Turkish: اوقه) was an Ottoman measure of mass, equal to 400 dirhems (Ottoman drams). Its value varied, but it was standardized in the late empire as 1.2829 kilograms. 'Oka' is the most usual spelling today; 'oke' was the usual contemporary English spelling; 'okka' is the modern Turkish spelling, and is usually used in academic work about the Ottoman Empire.

Key takeaways

Oka (mass) belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Oka (mass) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Oka (mass) from memory before moving on to harder problems.

Reference excerpt

The oka, okka, or oke (Ottoman Turkish: اوقه) was an Ottoman measure of mass, equal to 400 dirhems (Ottoman drams). Its value varied, but it was standardized in the late empire as 1.2829 kilograms. 'Oka' is the most usual spelling today; 'oke' was the usual contemporary English spelling; 'okka' is the modern Turkish spelling, and is usually used in academic work about the Ottoman Empire. In Albania, oka varied in weight between 1.25 kg (small oka) and 1.408 kg (large oka) depending on the region. It was formally replaced by the metric system in 1922 but continued to be used until a comprehensive implementation of the metric system in 1946. In Turkey, the traditional unit is now called the eski okka 'old oka' or kara okka 'black okka'; the yeni okka 'new okka' is the kilogram. In Greece, the oka (οκά, plural οκάδες) was standardized at 1.282 kg and remained in use until traditional units were abolished on March 31, 1953—the metric system had been adopted in 1876, but the older units remained in use. In Cyprus, the oka was equal to 1.270058636 kg or 4 onjas, each weighing 100 drams, and it remained in use until 1986, when Cyprus adopted the metric system. In Egypt, the monetary oka weighed 1.23536 kg. In Tripolitania, it weighed 1.2208 kg, equal to 2½ artals. The oka was also used as a unit of volume. In Wallachia, it was 1.283 liters of liquid and 1.537 L of grain (dry measure). In Greece, an oka of oil was 1.280 kg, which would have translated to about 1.340 litres (at 0.916 kg/l).

References

General references A.D. Alderson and Fahir İz, The Concise Oxford Turkish Dictionary, 1959 Γ. Μπαμπινιώτης (Babiniotis), Λεξικό της Νέας Ελληνικής Γλώσσας, Athens, 1998 Encyclopædia Britannica Eleventh Edition, 1911 La Grande Encyclopédie Diran Kélékian, Dictionnaire Turc-Français, Constantinople: Imprimerie Mihran, 1911 OED

Worked examples

Example 1 — a first encounter with Oka (mass)

Start with the simplest possible case. Write down what Oka (mass) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Oka (mass) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Oka (mass) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Oka (mass)

In research: Oka (mass) appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Oka (mass) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Oka (mass) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Obsolete units of measurement, Ottoman units of measurement, Unit of measurement stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Oka (mass) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Oka (mass) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Oka (mass) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Oka (mass) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Oka (mass) in simple terms?

Why does Oka (mass) matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Oka (mass)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Oka (mass).