1. Home
  2. GK Questions
  3. General Science
  4. Properties of Matter

Properties of Matter — GK Questions with Answers

10 General Science Questions20 General Science Questions50 General Science Questions100 General Science Questions Current Affairs 2026 Today's GK Quiz Static GK हिन्दी
34 questions
  1. Which state of matter is the most compressible?
    1. solid
    2. gas
    3. liquid
    4. all equal
    Show answer

    Answer: (B) gas

    Gas molecules have a lot of empty space between them, so a gas can be squeezed smaller (LPG, CNG cylinders).

  2. In which state is the matter of the Sun and stars?
    1. solid
    2. liquid
    3. BEC
    4. plasma
    Show answer

    Answer: (D) plasma

    At very high temperature atoms get ionised — this is the plasma state, the commonest in the universe.

  3. Under what condition does a Bose–Einstein condensate (BEC) form?
    1. very close to absolute zero
    2. at very high temperature
    3. at very high pressure
    4. at normal temperature in vacuum
    Show answer

    Answer: (A) very close to absolute zero

    A BEC forms a few nanokelvin above absolute zero, when all the atoms drop into the same lowest-energy state.

  4. Which of these sublimes?
    1. salt
    2. sugar
    3. camphor
    4. wax
    Show answer

    Answer: (C) camphor

    On heating, camphor turns straight into vapour without melting — that is sublimation.

  5. What kind of solid is glass?
    1. crystalline
    2. metallic
    3. amorphous
    4. ionic crystal
    Show answer

    Answer: (C) amorphous

    Glass has irregular particles and no sharp melting point — it is called a supercooled liquid or amorphous solid.

  6. What is the unit of strain?
    1. no unit
    2. N/m
    3. J
    4. N/m²
    Show answer

    Answer: (A) no unit

    Strain = change in shape ÷ original shape — a ratio, so it has no unit.

  7. Which is more elastic, rubber or steel?
    1. rubber
    2. cannot say
    3. both equal
    4. steel
    Show answer

    Answer: (D) steel

    Steel’s Young’s modulus is far larger than rubber’s — it deforms less for the same force and returns more strongly, so it is more elastic.

  8. Which modulus of elasticity do liquids have?
    1. Young’s modulus
    2. bulk modulus
    3. rigidity modulus
    4. all three
    Show answer

    Answer: (B) bulk modulus

    A liquid has no fixed shape, so it has only a bulk modulus.

  9. Up to which point on the stress–strain curve does Hooke’s law hold?
    1. up to the proportional limit
    2. up to the yield point
    3. up to fracture
    4. up to the ultimate strength
    Show answer

    Answer: (A) up to the proportional limit

    Only the first straight part of the curve (up to the proportional limit) obeys Hooke’s law.

  10. If the length and the radius of a wire are both doubled, the extension under the same load becomes —
    1. double
    2. four times
    3. half
    4. the same
    Show answer

    Answer: (C) half

    ΔL = FL/(πr²Y) → L doubles and r² becomes four times → ΔL becomes half.

  1. Springs are made of steel and not copper because —
    1. steel is cheaper
    2. steel has a larger Young’s modulus
    3. copper rusts
    4. steel is lighter
    Show answer

    Answer: (B) steel has a larger Young’s modulus

    Steel is more elastic, so it stretches again and again and still returns properly.

  2. Which is the densest liquid?
    1. water
    2. kerosene
    3. glycerine
    4. mercury
    Show answer

    Answer: (D) mercury

    The density of mercury is about 13,600 kg/m³ — 13.6 times that of water.

  3. Which instrument checks the purity of milk?
    1. hydrometer
    2. manometer
    3. barometer
    4. lactometer
    Show answer

    Answer: (D) lactometer

    A lactometer measures the relative density of milk; adding water lowers it.

  4. Why is the wall of a dam made thicker at the bottom?
    1. for beauty
    2. water pressure increases with depth
    3. water is denser at the top
    4. to save soil
    Show answer

    Answer: (B) water pressure increases with depth

    Fluid pressure P = hρg grows with depth, so the lower wall has to bear more pressure.

  5. Hydraulic brakes work on which law?
    1. Archimedes
    2. Bernoulli
    3. Pascal
    4. Hooke
    Show answer

    Answer: (C) Pascal

    By Pascal’s law the pressure applied on the pedal travels through the enclosed liquid equally to all four wheels.

  6. In a hydraulic lift the small piston has area 5 cm² and the large one 250 cm². A 100 N push on the small one gives what force on the large one?
    1. 5000 N
    2. 2500 N
    3. 500 N
    4. 25000 N
    Show answer

    Answer: (A) 5000 N

    F₂ = F₁ × A₂/A₁ = 100 × 250/5 = 5000 N.

  7. What is the atmospheric pressure at sea level, roughly?
    1. 76 mm of mercury
    2. 76 cm of mercury
    3. 7.6 m of mercury
    4. 760 cm of mercury
    Show answer

    Answer: (B) 76 cm of mercury

    1 atm = a 76 cm (760 mm) mercury column = 1.013 × 10⁵ Pa.

  8. If the barometer reading suddenly falls a lot, it signals —
    1. clear weather
    2. no hailstorm
    3. cold
    4. a storm
    Show answer

    Answer: (D) a storm

    A sudden big fall in pressure signals an approaching gale or cyclone; a slow fall signals rain.

  9. Why is mercury used in a barometer instead of water?
    1. mercury is very dense, so a short tube is enough
    2. mercury is cheap
    3. mercury is transparent
    4. mercury heats up quickly
    Show answer

    Answer: (A) mercury is very dense, so a short tube is enough

    A water barometer needs a tube about 10.3 m long; a mercury one needs only 76 cm.

  10. The buoyant force does not depend on —
    1. density of the fluid
    2. volume dipped
    3. mass of the body
    4. g
    Show answer

    Answer: (C) mass of the body

    F_B = Vρ(fluid)g — the body’s mass or material does not appear in it.

  1. A body weighs 60 N in air and 40 N in water. Its relative density?
    1. 1.5
    2. 2
    3. 3
    4. 6
    Show answer

    Answer: (C) 3

    Relative density = weight in air ÷ loss of weight = 60 ÷ 20 = 3.

  2. An iron nail sinks in water but an iron ship floats, because —
    1. the ship displaces water equal to its own weight
    2. the iron of the ship is lighter
    3. sea water is warm
    4. the ship is painted
    Show answer

    Answer: (A) the ship displaces water equal to its own weight

    Because of its hollow shape the ship displaces a huge amount of water, whose weight becomes equal to the ship’s weight.

  3. If an ice cube floating on water in a glass melts completely, the water level —
    1. rises
    2. falls
    3. first rises then falls
    4. stays the same
    Show answer

    Answer: (D) stays the same

    Floating ice displaces water equal to its own weight; on melting it becomes exactly that much water, so the level does not change.

  4. When a ship comes from a river into the sea it —
    1. sinks deeper
    2. rises a little
    3. shows no change
    4. sinks
    Show answer

    Answer: (B) rises a little

    Sea water is denser, so equal buoyancy comes from displacing less volume.

  5. Raindrops are round because of —
    1. surface tension
    2. viscosity
    3. gravity
    4. atmospheric pressure
    Show answer

    Answer: (A) surface tension

    Surface tension shrinks the surface to the least area, and for a fixed volume a sphere has the least surface.

  6. On raising the temperature, the surface tension of a liquid —
    1. increases
    2. stays the same
    3. decreases
    4. first rises then falls
    Show answer

    Answer: (C) decreases

    Higher temperature weakens molecular attraction, so surface tension falls and becomes zero at the critical temperature.

  7. Sprinkling kerosene on still water kills mosquito larvae because —
    1. the oil is poisonous
    2. surface tension falls
    3. the water gets hot
    4. viscosity rises
    Show answer

    Answer: (B) surface tension falls

    The oil film lowers surface tension, so the larvae cannot stay at the surface and sink and die.

  8. Why is mercury pushed down in a glass capillary tube?
    1. angle of contact less than 90°
    2. mercury has zero viscosity
    3. mercury is light
    4. angle of contact more than 90°
    Show answer

    Answer: (D) angle of contact more than 90°

    The angle of contact of mercury and glass is about 135°–140°; cohesion is more than adhesion, so mercury is pushed down and the meniscus is convex.

  9. If the radius of a capillary tube is halved, the rise of water becomes —
    1. half
    2. the same
    3. four times
    4. double
    Show answer

    Answer: (D) double

    h = 2T cosθ/(rρg) — h ∝ 1/r, so halving the radius doubles the rise.

  10. On raising the temperature, the viscosity of gases —
    1. decreases
    2. increases
    3. does not change
    4. becomes zero
    Show answer

    Answer: (B) increases

    Hot gas molecules move faster and share more momentum between layers, so a gas’s viscosity rises (a liquid’s falls).

  1. By Stokes’ law, the terminal velocity of a falling sphere is proportional to —
    1. r
    2. 1/r
    3. r²
    4. r³
    Show answer

    Answer: (C) r²

    vₜ = 2r²(ρ − σ)g/9η — proportional to the square of the radius; that is why tiny cloud droplets fall very slowly.

  2. If the diameter of a pipe is halved, the velocity of water becomes —
    1. four times
    2. double
    3. half
    4. the same
    Show answer

    Answer: (A) four times

    Equation of continuity A₁v₁ = A₂v₂: diameter half → area 1/4 → velocity 4 times.

  3. An aircraft wing lifts the plane by which principle?
    1. Pascal’s law
    2. Bernoulli’s principle
    3. Archimedes’ principle
    4. Hooke’s law
    Show answer

    Answer: (B) Bernoulli’s principle

    Air flows faster over the wing, so the pressure there is lower; the higher pressure below pushes the wing up.

  4. With what velocity does water come out of a hole 20 m below the surface in a tank (g = 10)?
    1. 10 m/s
    2. 14 m/s
    3. 200 m/s
    4. 20 m/s
    Show answer

    Answer: (D) 20 m/s

    Torricelli: v = √(2gh) = √(2 × 10 × 20) = √400 = 20 m/s.

More chapters in this subject