Bahria Admission Test key terms

A conclusion a reader draws from evidence in a passage rather than from a statement made outright. It must be supported by the text, not by personal opinion.

The central point a passage conveys, usually stated or implied in a topic sentence. Every supporting detail should relate back to it.

The writer's attitude toward the subject, revealed through word choice and sentence structure. It differs from mood, which is the feeling created in the reader.

The emotional or cultural association a word carries beyond its literal meaning. For example, 'cheap' and 'affordable' share denotation but differ in connotation.

A word or phrase that signals the logical relationship between ideas, such as contrast, cause, addition, or example. Choosing the wrong transition breaks the flow.

The grammatical rule that a verb must match its subject in number and person. Intervening phrases and inverted sentence order often hide the true subject.

A modifier whose intended subject is missing or misplaced, so it appears to describe the wrong noun. Example: 'Walking home, the rain started.'

A word that is close in meaning to another word. Few synonyms are fully interchangeable; register, collocation, and connotation often decide which fits.

The expression b² − 4ac in a quadratic equation ax² + bx + c = 0. Its sign tells whether the roots are real and distinct, real and equal, or complex.

An equation of the form ax² + bx + c = 0 with a not equal to zero. Its solutions can be found by factoring, completing the square, or the quadratic formula.

A sequence in which each term after the first is obtained by adding a fixed constant called the common difference. Its nth term is a + (n−1)d.

A sequence in which each term is obtained by multiplying the previous term by a fixed ratio. Its nth term is ar^(n−1), and it converges only when the absolute value of r is less than 1.

An arrangement of objects in which order matters. The number of permutations of n distinct objects taken r at a time is n! divided by (n−r)!.

A selection of objects in which order does not matter. The number of ways to choose r objects from n is n! divided by r!(n−r)!.

A number between 0 and 1 measuring how likely an event is, calculated as favourable outcomes divided by total equally likely outcomes in simple cases.

The instantaneous rate at which a function changes with respect to its variable, defined as the limit of a difference quotient. Geometrically it gives the slope of the tangent line.

The value a function approaches as its input approaches a particular point, whether or not the function equals that value there. Limits underpin continuity and derivatives.

A deductive argument with two premises and a conclusion, where the conclusion must follow if the premises are true. Validity depends on form, not content.

The statement formed by swapping and negating both parts of a conditional: 'If P then Q' becomes 'If not Q then not P.' It is logically equivalent to the original.

The statement formed by swapping the hypothesis and conclusion of a conditional. 'If P then Q' becomes 'If Q then P,' which is not logically equivalent to the original.

A condition that must hold for a statement to be true, though it alone may not be enough. In 'P only if Q,' Q is necessary for P.

A condition whose truth guarantees the truth of a statement, though other conditions might also guarantee it. In 'if P then Q,' P is sufficient for Q.

An unstated premise that an argument relies on to reach its conclusion. Spotting the assumption is often the key to evaluating or weakening the argument.

A pattern of reasoning that is psychologically persuasive but invalid. Examples include attacking the person instead of the argument and begging the question.

A diagram using overlapping circles to show how sets relate. It is a standard tool for testing whether a categorical syllogism's conclusion is forced by its premises.

The net force on an object equals its mass times its acceleration, F = ma. It links force, mass, and acceleration and is the basis for most dynamics problems.

The product of an object's mass and velocity, a vector quantity. In an isolated system, total momentum is conserved in collisions.

For a conductor at constant temperature, the current through it is directly proportional to the potential difference across it, V = IR, where R is resistance.

The bending of a wave as it passes from one medium to another where its speed changes. Snell's law relates the angles to the refractive indices.

The time required for half the nuclei in a radioactive sample to decay, or for half a drug's concentration to be eliminated. It is independent of the starting amount.

The amount of substance containing 6.022 × 10²³ particles. It bridges the microscopic count of atoms and the macroscopic mass measured in grams.

The number of moles of solute dissolved per litre of solution, expressed in mol/L. It changes slightly with temperature because volume expands.

Loss of electrons by a substance, accompanied by an increase in oxidation number. It is always paired with reduction in a redox reaction.

When a system at equilibrium is disturbed by a change in concentration, pressure, or temperature, it shifts to counteract the change and restore equilibrium.

A measure of hydrogen-ion concentration equal to minus the logarithm of the hydrogen-ion concentration. Values below 7 are acidic, above 7 basic, and 7 is neutral at 25 °C.

Cell division producing two genetically identical daughter cells with the same chromosome number. It underlies growth, tissue repair, and asexual reproduction.

A protein catalyst that speeds up a biochemical reaction by lowering its activation energy. Enzymes are specific to substrates and sensitive to temperature and pH.

The movement of water molecules across a partially permeable membrane from a region of higher water potential to one of lower water potential.

The process in which green plants use light energy to convert carbon dioxide and water into glucose and oxygen, catalysed by chlorophyll in chloroplasts.

The maintenance of a stable internal environment within narrow limits despite external change, achieved through negative feedback mechanisms such as thermoregulation.