Physical Quantities & Measurements Chapter 1 Class 9 Physics KPK Board MCQs | Class Nine Physics Chapter 1 MCQs KPK Board

He studied how sound travels and how the human ear receives sound.

Scientific notation helps express extremely large or small values easily.

He encouraged science development and education in Pakistan.

He played a major role in developing Pakistan’s nuclear capabilities.

Trailing zeros without decimal → ambiguous.

Scalars have only magnitude (e.g., time, mass).

Physics explains how matter and energy interact in the universe.

Example: 205 → all three digits are significant.

Screw gauge is best for very small thickness.

He wrote over 200 books on philosophy, mathematics, and science.

The standard SI unit for length is meter (m).

Mass is one of the seven SI base quantities.

Counting places moved tells the exponent of 10.

“Nano” = one-billionth = 10⁻⁹.

“Mega” means 1,000,000 = 10⁶.

Physics is the study of matter, energy, and the laws governing them.

More divisions → smaller least count → more accuracy.

3000 = 3 × 10³ because the decimal moves 3 places.

Observing these objects helps understand physics concepts like motion, gravity, and light.

2.0 → significant digits: 2 and 0 → 2 sig figs.

Measuring cylinders have volume markings in mL.

The SI unit of time is second (s).

Next digit is 1 (<5) → keep 4.32.

Joule (J) is derived from kg·m²/s².

Numbers 1–9 are always significant.

Second (s) is the SI base unit of time.

Vectors include magnitude + direction (e.g., force, velocity).

Scientific method starts with observing a problem or a phenomenon.

Dr. Abdus Salam received the Nobel Prize in Physics in 1979 for his work on electroweak theory.

4.500 has 4 sig figs.

His work was central to Pakistan becoming a nuclear-capable nation.

The Quran describes natural phenomena as “signs” (Ayat) of Allah.

Volume is found by water displacement in a measuring cylinder.

Third digit is 9 (>5) → 2.4 becomes 2.5.

Screw gauge has a circular scale for fine readings.

Pascal (Pa) is a derived unit of pressure.

3,200,000 → 3.2 × 10⁶ (moved 6 places).

Leading zeros are not counted → digits 4 and 5 are significant.

Smartphones work due to electrical circuits and electromagnetic waves, studied in physics.

Zoology is a branch of biology, not physics.

Trailing zeros after decimal ARE significant → 7.00 = 3 significant figures.

Volume is derived from length × width × height.

Vernier caliper includes both scales for accurate measurements.

Force is a derived quantity (F = m × a).

Screw gauge is used to measure very small thickness accurately.

Electric current (a base quantity) is measured in amperes.

Standard/scientific form always requires a number between 1 and 10.

Significant digits: 3,0,4,0 → 4 sig figs.

He improved scientific thinking and contributed to optics and mathematics.

He proved light travels in straight lines, a basic concept in optics.

“Tera” = 1,000,000,000,000 = 10¹².

7, 0, 0 (decimal present → all significant).

Leading zeros don’t count; only 9 is significant.

Vernier caliper can measure inside, outside, and depth.

Least count defines the minimum measurable quantity.

Standard form uses the format a × 10ⁿ, where 1 ≤ a < 10.

“Micro” = one-millionth = 10⁻⁶.

His Nobel Prize-winning work was on electroweak unification.

He used geometry to calculate mountain heights accurately.

Moving the decimal 4 places to the right gives exponent –4.

A positive exponent moves the decimal right, and a negative exponent moves it left.

Optics deals with the behavior and properties of light.

Next digit is 6 (>5) → 7.8 becomes 7.9.

Kilogram (kg) is the SI base unit of mass.

Length can be measured, so it is a physical quantity.

1 mm = 0.1 cm is the smallest reading on most meter rules.

Screw gauge has the highest accuracy (0.01 mm).

Standard form requires shifting the decimal point to make a number between 1 and 10.

The Quran repeatedly asks humans to think, reflect, and observe the world.

Speed is measured in meters per second, a derived unit.

He was involved with CERN and contributed to theoretical particle physics.

Next digit is 1 → 9.95 becomes 9.96.

Ibn al-Haitham is called the Father of Optics because of his scientific studies of light.

Ibn al-Haitham introduced experimentation to test scientific ideas.

“Pico” (10⁻¹²) is smaller than milli (10⁻³), micro (10⁻⁶), and nano (10⁻⁹).

Pascal (Pa) = Newton per square meter (N/m²).

Any number raised to the power 0 equals 1.

A.Q. Khan is known as the key figure behind Pakistan’s nuclear program.

Thermodynamics focuses on heat and temperature.

Stopwatch measures time accurately.

Decimal present → all zeros count → 1,0,0,0 → 4 sig figs.

Density is formed by dividing mass by volume, so it is derived.

Only 4.5 is between 1 and 10, making option (c) correct.

Isaac Newton is commonly known as the Father of Physics.

He specialized in metallurgy, which is important in nuclear technology.

“Milli” means one-thousandth = 10⁻³.

The depth rod extends to measure holes or cavities.

“Centi” means 1/100 = 10⁻².

“Kilo” means 1000, which is 10³.

Ibn al-Haitham explained how the pinhole camera forms images.

He studied metallurgy and nuclear engineering in Europe.

Time is a fundamental base quantity measured in seconds.

Sig figs are 5, 0, 6, 0 → total 4.

Decimal moves 3 places to the right, so exponent is −3.

Temperature is a base quantity in SI units.

Standard form uses the format A × 10ⁿ, where A is between 1 and 10.

The first part (a) must be at least 1 but less than 10.

Moving left makes the number smaller, so exponent becomes positive.

Physical balance compares two masses using two pans.

Trailing zero without decimal is NOT significant → 25 → 2 significant figures.

In standard form, the first number must be 1 to 10, but 0.2 is less than 1.

“Giga” means one-billion = 10⁹.

Moving the decimal 3 places to the left gives 0.005.

He used experiments to verify scientific ideas.

If dropping digit < 5 → no change.

The Quran repeatedly invites humans to think, observe, and understand the natural world.

Ampere (A) is the SI base unit of electric current.

Al-Biruni worked in astronomy, physics, and mathematics.

Physical balance compares masses of objects.

He corrected the old belief and explained that vision happens when light from objects enters the eyes.

The Quran motivates learning about the universe and its physical phenomena.

A stopwatch measures time intervals.

Physics studies the formation, structure, and behavior of the universe.

Yaqub Kindi made early contributions in optics and mathematics.

Stopwatch measures time intervals.

The standard SI unit of mass is kilogram (kg).

The Quran mentions balance and order, which aligns with physical laws governing the universe.

Both the Quran and physics promote the study of the universe to gain knowledge.

Derived quantities are formed using combinations of base quantities.

Kelvin (K) is the SI base unit of temperature.

A meter rule measures lengths in centimeters and millimeters.

4500 → 4.5 × 10³ (decimal moves 3 places left).

Moving right means the number was originally very small → negative exponent.

10² = 100, so 7.2 × 100 = 720.

The number with 4 sig figs is d) 0.560?

Vernier caliper typically has a least count of 0.1 mm.

Newton (N) is a derived unit for force.

Meter (m) is the standard SI base unit for length.

He proved that objects send light into the eye, forming images.

Kitab al-Manazir is his famous book on the science of optics.

Base quantities are independent and cannot be written using other quantities.

Kelvin (K) is the SI unit of temperature, a base quantity.

He compared densities of many substances using scientific methods.

He studied minerals, their density, and various physical properties.

Physics explains natural laws, which enhances appreciation of the universe mentioned in the Quran.

He used scientific methods involving angles and shadows.

He encouraged logical thinking and scientific reasoning.

Screw gauge is very accurate with a least count of 0.01 mm.

Speed is derived from length/time, so it is a derived quantity.

Physics explains machines, forces, and motion.

If dropping digit > 5 → round UP.

“Pico” = one-trillionth = 10⁻¹².

Speed is derived from length divided by time.

Vernier caliper is used for accurate measurement of length.

Third digit is 7 (>5) → 5.6 becomes 5.7.

He played an important role in translating Greek scientific works into Arabic.

Mechanics studies motion and the forces that affect motion.

He contributed to the development of PINSTECH and science education in Pakistan.

The Quran states that the sun and moon move in their fixed courses, matching astronomical observations.

Vernier caliper can measure round objects accurately.

He wrote Kitab-ul-Hind, a scientific study of India’s culture, math, and science.