PAF Airman Initial Test key terms

A word that means nearly the same as another word in a given context, such as 'big' and 'large'. Synonym questions test vocabulary by asking you to choose the closest match from the options given.

A word whose meaning is opposite to another word, such as 'hot' and 'cold' or 'ancient' and 'modern'. Antonym questions ask for the option most nearly opposite in meaning to the given word.

A fixed group of words whose meaning cannot be worked out from the individual words, such as 'break the ice' meaning to start a conversation. Idioms are learned as whole expressions.

A small word placed before a noun or pronoun to show position, direction or time, such as in, on, at, under, between and after. It links that noun to another part of the sentence.

A sentence pattern in which the subject performs the action, as in 'Ali wrote the letter'. The passive form would be 'The letter was written by Ali'.

One of two or more words that sound the same but are spelt differently and carry different meanings, such as 'sea' and 'see', or 'their' and 'there'.

A group of words that contains its own subject and verb. An independent clause can stand alone as a sentence, while a dependent clause cannot and must attach to a main clause.

The least common multiple: the smallest positive number that is a multiple of two or more given numbers. For 4 and 6 the multiples first meet at 12, so the LCM is 12.

The highest common factor: the largest number that divides two or more given numbers exactly, leaving no remainder. For 12 and 18 the common factors are 1, 2, 3 and 6, so the HCF is 6.

A whole number greater than 1 whose only exact divisors are 1 and itself, such as 2, 3, 5, 7 and 11. The number 1 is not counted as prime.

A comparison of two quantities of the same kind, written as 3:2 and read 'three to two'. It states how many times one quantity contains the other.

A fraction expressed as a part of one hundred, so 45% means 45 out of every 100, or 0.45. Percentages make comparison between differently sized quantities easier.

The average found by adding all the values and dividing by how many values there are. For 2, 4 and 9 the total is 15, so the mean is 5.

Money paid for the use of a principal sum, charged only on the original amount. It is found by multiplying principal, yearly rate and time in years, then dividing by 100.

In a right-angled triangle the square of the longest side, the hypotenuse, equals the sum of the squares of the other two sides, so a squared plus b squared equals c squared.

A push or a pull that can change an object's speed, direction or shape. Force is measured in newtons and has both size and direction.

A physical quantity fully described by its size alone, with no direction needed. Mass, time, distance, speed and temperature are common examples used in physics calculations.

A physical quantity that needs both size and direction to be fully described, such as displacement, velocity, acceleration and force. Vectors combine by direction, not by simple arithmetic addition.

The rate at which velocity changes with time, measured in metres per second squared. A car going from rest to 20 m/s in 5 seconds accelerates at 4 m/s each second.

The mass of a substance per unit volume, found by dividing its mass by its volume. Water has a density of about 1000 kilograms per cubic metre.

For a conductor kept at constant temperature, current is directly proportional to voltage, giving voltage equals current times resistance. Voltage is in volts, current in amperes and resistance in ohms.

The bending of light as it passes from one transparent medium into another of different optical density, for example from air into water, caused by a change in the light's speed.

In physics, work is done when a force moves an object through a distance in the direction of the force. Work equals force times distance and is measured in joules.

The process by which green plants use sunlight, water and carbon dioxide to make glucose and release oxygen. Chlorophyll in the leaves traps the light energy needed for the reaction.

The release of energy from food inside living cells, usually using oxygen and producing carbon dioxide and water. It happens in all living cells, both day and night.

The smallest particle of an element that still keeps the properties of that element. It has a central nucleus of protons and neutrons with electrons moving around it.

A substance that turns blue litmus paper red, reacts with metals to give hydrogen gas and neutralises bases. Lemon juice, vinegar and hydrochloric acid are common examples.

A community of living things together with the non-living surroundings they interact with, such as a pond, forest or desert, where energy flows and materials are recycled.

The five core duties of a Muslim: the declaration of faith (shahadah), the five daily prayers (salah), obligatory charity (zakah), fasting in Ramadan (sawm) and pilgrimage to Makkah (hajj).

An obligatory yearly charitable payment on wealth that has been held for a full year and exceeds a fixed minimum. It is normally two and a half per cent of savings and similar assets.

The direction Muslims face during prayer, which is towards the Ka'bah in Makkah. Inside a mosque this direction is shown by the mihrab, a niche set in one wall.

The ninth month of the Islamic lunar calendar, during which Muslims fast from dawn to sunset and give extra attention to prayer and charity. The month ends with the festival of Eid al-Fitr.

The Islamic lunar calendar of twelve months, beginning with Muharram, used to fix religious dates such as Ramadan and the Hajj. Its year is about eleven days shorter than the solar year.

An international organisation founded in 1945 to keep peace, protect human rights and promote development. Its main bodies include the General Assembly and the Security Council.

The distance of a place north or south of the equator, measured in degrees from 0 degrees at the equator to 90 degrees at the poles. Lines of latitude run east to west.

A reasoning question that pairs two items with a stated relationship and asks you to find another pair with the same relationship, for example 'hand is to glove as foot is to sock'.

A list of numbers that follows a hidden rule, such as adding 3 each time or doubling each term. You must find the rule and use it to supply the next or missing number.

A reasoning task in which letters or words are replaced by a pattern, such as shifting every letter one place forward in the alphabet, and you must apply the same rule to a new word.

A set of items in which all but one share a common feature, and you must identify the item that does not fit, such as 'apple, banana, carrot, mango' where carrot is the odd one.

A puzzle that describes family links in words, such as 'the son of my mother's brother', and asks how two named people are related to each other.