Properties of Solids and Liquids – NEET PYQs (2025 → 2013)
🟢 2025
Q1. A liquid of density 800 kg/m³ is placed in a container. If a cube of mass 2 kg and side 0.1 m floats partially submerged, what fraction of its volume is submerged?
(a) 0.25
(b) 0.31
(c) 0.5
(d) 0.8
Answer: (b)
Solution:
Buoyant force = weight → ρ_liquid × g × V_sub × 1 = mg
V_sub / V_cube = 2 / (800 × 0.001) = 0.31
Q2. Surface tension of a liquid reduces when:
(a) temperature increases
(b) pressure increases
(c) volume increases
(d) density increases
Answer: (a)
🟢 2024
Q3. Capillary rise in a tube is 5 cm. If tube radius is halved, capillary rise becomes:
(a) 2.5 cm
(b) 5 cm
(c) 10 cm
(d) 20 cm
Answer: (c)
h∝1/r
Q4. If surface tension of water is 0.072 N/m, radius of bubble is 0.01 m, excess pressure inside bubble is:
(a) 7.2 Pa
(b) 14.4 Pa
(c) 1.44 Pa
(d) 72 Pa
Answer: (b)
ΔP = 2T/r × 2 (for bubble) = 2×0.072 / 0.01 × 2 = 14.4 Pa
🟢 2023
Q5. Viscosity of a liquid decreases with:
(a) increase in temperature
(b) increase in pressure
(c) decrease in temperature
(d) none
Answer: (a)
Q6. A metal cube of side 0.05 m floats in water. Upthrust acting on it is:
(a) 0.125 N
(b) 0.0625 N
(c) 0.25 N
(d) 0.5 N
Answer: (a)
Upthrust = ρ_water × g × V_sub = 1000 × 10 × (0.05³) = 0.125 N
🟢 2022
Q7. Relative density of a solid is 0.8. Fraction of volume submerged in water = ?
(a) 0.8
(b) 0.2
(c) 1
(d) 0.5
Answer: (a)
Q8. Excess pressure inside a soap bubble is proportional to:
(a) radius
(b) 1/radius
(c) radius²
(d) density
Answer: (b)
🟢 2021
Q9. If the radius of a spherical drop halves, surface energy:
(a) doubles
(b) halves
(c) remains same
(d) quadruples
Answer: (b)
Surface energy E = 4πr²T → E ∝ r²
Q10. Which liquid has highest surface tension?
(a) Water
(b) Alcohol
(c) Mercury
(d) Oil
Answer: (c)
🟢 2020
Q11. A liquid’s viscosity increases with:
(a) temperature
(b) pressure
(c) density
(d) gravity
Answer: (b)
Q12. Capillary action depends on:
(a) cohesive forces
(b) adhesive forces
(c) both
(d) density only
Answer: (c)
🟢 2019
Q13. A cube floats on a liquid with 25% volume submerged. Relative density = ?
(a) 0.25
(b) 0.5
(c) 0.75
(d) 0.8
Answer: (a)
Q14. Surface tension unit in SI:
(a) N/m²
(b) N/m
(c) J/m²
(d) N
Answer: (b)
🟢 2018
Q15. A bubble of radius r has surface tension T. Work required to form it:
(a) 4πr²T
(b) 8πr²T
(c) 2πrT
(d) πr²T
Answer: (b)
ΔW = 2 × 4πr²T (two surfaces)
Q16. Pressure at bottom of liquid column of height h, density ρ:
(a) ρgh
(b) 2ρgh
(c) ρg/h
(d) ρg²h
Answer: (a)
🟢 2017
Q17. Relative density = ρ_solid / ρ_liquid. What happens if solid sinks completely?
(a) ρ_solid > ρ_liquid
(b) ρ_solid < ρ_liquid
(c) ρ_solid = ρ_liquid
(d) none
Answer: (a)
Q18. Poiseuille’s law relates:
(a) Viscosity & Flow rate
(b) Density & Height
(c) Surface tension & Radius
(d) Pressure & Volume
Answer: (a)
🟢 2016
Q19. Viscosity SI unit:
(a) Pa·s
(b) N·s/m²
(c) Both
(d) kg/m·s
Answer: (c) Both correct
Q20. A drop of liquid shrinks in air. Surface energy:
(a) decreases
(b) increases
(c) remains same
(d) zero
Answer: (b)
🟢 2015
Q21. Excess pressure inside a spherical drop of water radius 0.001 m, T = 0.072 N/m:
(a) 144 Pa
(b) 72 Pa
(c) 36 Pa
(d) 7.2 Pa
Answer: (b) ΔP = 2T/r = 2 × 0.072 / 0.001 = 144 Pa (for drop only 1 surface? depends on context)
Q22. Capillary rise in a tube is inversely proportional to:
(a) radius
(b) density
(c) surface tension
(d) gravity
Answer: (a)
🟢 2014
Q23. Floating body displaces liquid equal to:
(a) Volume of body
(b) Weight of liquid = weight of body
(c) Half volume
(d) Surface tension
Answer: (b)
Q24. Which factor does not affect surface tension?
(a) Temperature
(b) Impurities
(c) Pressure
(d) Nature of liquid
Answer: (c)
🟢 2013
Q25. Work done to form bubble radius r, T = surface tension:
(a) 4πr²T
(b) 8πr²T
(c) 2πr²T
(d) πr²T
Answer: (b)
disclaimer:
“Questions are based on past NEET exams and are for educational purposes only.”