PPSC Subject Specialist Test General Knowledge & Everyday Science Syllabus

Which line marks the disputed border between Pakistan and India in Kashmir, and which line borders Afghanistan?

The Line of Control (LoC) divides Kashmir between Pakistan and India; the Durand Line is the Pakistan–Afghanistan border.

What are the SI base units for length, mass, time, and electric current?

Metre (length), kilogram (mass), second (time), and ampere (electric current).

What is the SI unit of force, and how is it defined?

The newton (N); one newton is the force that gives a 1 kg mass an acceleration of 1 m/s² (1 N = 1 kg·m/s²).

What is the difference between scalar and vector quantities? Give one example of each.

A scalar has only magnitude (e.g., mass or speed); a vector has both magnitude and direction (e.g., velocity or force).

What are the SI units of energy and power?

Energy is measured in joules (J); power is measured in watts (W), where 1 W = 1 J/s.

State Newton's three laws of motion briefly.

1) An object stays at rest or in uniform motion unless acted on by a net force (inertia). 2) Force equals mass times acceleration (F = ma). 3) For every action there is an equal and opposite reaction.

What is the formula for kinetic energy and potential energy (gravitational)?

Kinetic energy KE = ½mv²; gravitational potential energy PE = mgh.

State the law of conservation of energy.

Energy can neither be created nor destroyed; it only changes from one form to another, and the total energy of an isolated system remains constant.

What is the difference between mass and weight?

Mass is the amount of matter in a body (constant, in kg); weight is the gravitational force on it (W = mg, in newtons, varies with gravity).

What is the formula for work done by a force, and its SI unit?

Work = Force × distance moved in the direction of the force (W = F × d); its SI unit is the joule (J).

What are the three methods of heat transfer?

Conduction (through direct contact), convection (through fluid movement), and radiation (through electromagnetic waves, no medium needed).

What is the difference between reflection and refraction of light?

Reflection is the bouncing back of light from a surface; refraction is the bending of light as it passes from one medium to another due to a change in speed.

Why do we see lightning before we hear thunder?

Light travels much faster (~300,000 km/s) than sound (~343 m/s in air), so the flash reaches us before the sound.

What are the seven colours of the visible spectrum (white light) in order?

Violet, Indigo, Blue, Green, Yellow, Orange, Red (VIBGYOR).

Sound cannot travel through which medium, and why?

Sound cannot travel through a vacuum because it requires a material medium (solid, liquid, or gas) to transmit its vibrations.

What is the difference between conductors and insulators of electricity? Give an example of each.

Conductors allow electric current to flow easily (e.g., copper); insulators resist the flow of current (e.g., rubber or glass).

State Ohm's law and its formula.

At constant temperature, the current through a conductor is directly proportional to the voltage across it: V = I × R (Voltage = Current × Resistance).

What are the SI units of electric current, potential difference, and resistance?

Current is measured in amperes (A), potential difference in volts (V), and resistance in ohms (Ω).

What is the difference between AC and DC current?

Alternating current (AC) periodically reverses direction; direct current (DC) flows in only one direction.

What are the two poles of a magnet, and what is the basic law of magnetism?

North and south poles; like poles repel and unlike poles attract.

What is the difference between an element, a compound, and a mixture?

An element contains only one type of atom; a compound is two or more elements chemically combined in fixed ratios; a mixture is two or more substances physically combined and separable.

What is the difference between an atom and a molecule?

An atom is the smallest unit of an element that retains its properties; a molecule is two or more atoms chemically bonded together.

What is the chemical formula for water, and which elements does it contain?

H₂O; it contains two atoms of hydrogen and one atom of oxygen.

What is the pH scale, and what do values below, equal to, and above 7 indicate?

The pH scale runs 0–14; below 7 is acidic, exactly 7 is neutral, and above 7 is basic (alkaline).

What is produced when an acid reacts with a base (neutralisation reaction)?

A salt and water are produced (acid + base → salt + water).

Give the common name and chemical formula of common table salt, and of baking soda.

Table salt is sodium chloride (NaCl); baking soda is sodium bicarbonate (NaHCO₃).

What is the common name for the compound CaCO₃, and one of its everyday uses?

Calcium carbonate; it is found in limestone, marble, and chalk and is used in making cement and as an antacid.

Name two properties that distinguish metals from non-metals.

Metals are typically lustrous, malleable, ductile, and good conductors of heat/electricity; non-metals are usually dull, brittle, and poor conductors.

What is an alloy? Give two examples with their components.

An alloy is a mixture of a metal with other metals or elements. Examples: brass (copper + zinc) and steel (iron + carbon); bronze is copper + tin.

Which is the most reactive metal commonly cited and the most malleable metal?

Among common metals, potassium/sodium are highly reactive (alkali metals react vigorously with water); gold is the most malleable and ductile metal.