🧪 NEET Physics: Properties of Bulk Matter

50 MCQs with Answers & Explanations | +4/-1 Pattern | NEET 2026

📝 Key Formulae – Bulk Matter

Stress = F/A
Strain = ΔL/L
Y = FL/AΔL
ΔP = B(ΔV/V)
η = F/(A·dv/dx)
ΔL = LαΔT
ΔP = 4T/R (soap bubble)

Q1

The ratio of stress to strain within elastic limit is called:

A. Young’s modulus
B. Modulus of rigidity
C. Bulk modulus
D. Elastic limit

✅ Show Answer & Explanation

Answer: A. Young’s modulus
Explanation: Young’s modulus Y = stress/strain for longitudinal deformation within elastic limit.

Q2

A wire is stretched by 0.01 m when a force of 100 N is applied. If the same wire is stretched by 0.02 m, the force required will be:

A. 100 N
B. 200 N
C. 50 N
D. 400 N

✅ Show Answer & Explanation

Answer: B. 200 N
Explanation: F ∝ ΔL (Hooke’s law). Double extension → double force = 200 N.

Q3

The dimensional formula of Young’s modulus is:

A. ML⁻¹T⁻²
B. ML²T⁻²
C. MLT⁻²
D. ML⁻²T⁻²

✅ Show Answer & Explanation

Answer: A. ML⁻¹T⁻²
Explanation: Stress = Force/Area = MLT⁻²/L² = ML⁻¹T⁻². Strain is dimensionless, so Y has same dimensions.

Q4

Which of the following is more elastic?

A. Steel
B. Rubber
C. Glass
D. Copper

✅ Show Answer & Explanation

Answer: A. Steel
Explanation: Steel has higher Young’s modulus → more elastic (regains shape faster).

Q5

The bulk modulus of a liquid is 2 × 10⁹ N/m². The pressure required to reduce its volume by 0.2% is:

A. 4 × 10⁶ N/m²
B. 2 × 10⁶ N/m²
C. 8 × 10⁶ N/m²
D. 1 × 10⁶ N/m²

✅ Show Answer & Explanation

Answer: A. 4 × 10⁶ N/m²
Explanation: ΔP = B × (ΔV/V) = 2×10⁹ × 0.002 = 4×10⁶ N/m².

Q6

A wire of length L and radius r is stretched by a force F. If radius becomes r/2, the elongation for same force will:

A. Become 4 times
B. Become 2 times
C. Become 16 times
D. Remain same

✅ Show Answer & Explanation

Answer: A. Become 4 times
Explanation: ΔL ∝ 1/r², so radius half → area 1/4 → elongation 4 times.

Q7

The property due to which liquid surface behaves like a stretched membrane is:

A. Viscosity
B. Surface tension
C. Elasticity
D. Density

✅ Show Answer & Explanation

Answer: B. Surface tension
Explanation: Surface tension acts as stretched elastic membrane due to cohesive forces.

Q8

The excess pressure inside a soap bubble of radius R (surface tension T) is:

A. 4T/R
B. 2T/R
C. T/R
D. 8T/R

✅ Show Answer & Explanation

Answer: A. 4T/R
Explanation: Soap bubble has two surfaces (inner and outer), so ΔP = 4T/R.

Q9

The angle of contact for pure water with glass is:

A. 0°
B. 90°
C. 135°
D. 180°

✅ Show Answer & Explanation

Answer: A. 0°
Explanation: Pure water completely wets glass, so angle of contact is approximately 0°.

Q10

The terminal velocity of a sphere falling in a viscous fluid is proportional to:

A. r²
B. r
C. r³
D. 1/r

✅ Show Answer & Explanation

Answer: A. r²
Explanation: From Stokes’ law, v_term = (2r²g(ρ-σ))/(9η) → v ∝ r².

Q11

The coefficient of viscosity has dimensional formula:

A. ML⁻¹T⁻¹
B. MLT⁻¹
C. ML⁻²T⁻¹
D. ML⁻¹T⁻²

✅ Show Answer & Explanation

Answer: A. ML⁻¹T⁻¹
Explanation: η = F/(A·dv/dx) → MLT⁻² / (L²·T⁻¹) = ML⁻¹T⁻¹.

Q12

Water rises in a capillary tube of radius r up to height h. If radius is reduced to r/2, the new height will be:

A. 2h
B. h/2
C. 4h
D. h

✅ Show Answer & Explanation

Answer: A. 2h
Explanation: h ∝ 1/r, so radius half → height doubles.

Q13

The stress required to double the length of a wire (Y = 2×10¹¹ N/m²) is:

A. 2×10¹¹ N/m²
B. 1×10¹¹ N/m²
C. 4×10¹¹ N/m²
D. 0.5×10¹¹ N/m²

✅ Show Answer & Explanation

Answer: A. 2×10¹¹ N/m²
Explanation: Strain = 1, Y = stress/strain → stress = Y = 2×10¹¹ N/m².

Q14

The Young’s modulus of a material is 2×10¹¹ N/m². The force required to stretch a wire of length 2 m and area 1 mm² by 1 mm is:

A. 100 N
B. 200 N
C. 50 N
D. 400 N

✅ Show Answer & Explanation

Answer: A. 100 N
Explanation: F = Y × A × (ΔL/L) = 2×10¹¹ × 10⁻⁶ × (0.001/2) = 100 N.

Q15

A fluid is said to be ideal if it is:

A. Incompressible & non-viscous
B. Compressible & viscous
C. Incompressible & viscous
D. Compressible & non-viscous

✅ Show Answer & Explanation

Answer: A. Incompressible & non-viscous
Explanation: Ideal fluid: incompressible, non-viscous, irrotational flow.

Q16

Equation of continuity is based on conservation of:

A. Mass
B. Energy
C. Momentum
D. Angular momentum

✅ Show Answer & Explanation

Answer: A. Mass
Explanation: A₁v₁ = A₂v₂ represents mass conservation for steady incompressible flow.

Q17

Bernoulli’s equation is derived from conservation of:

A. Energy
B. Mass
C. Momentum
D. Force

✅ Show Answer & Explanation

Answer: A. Energy
Explanation: P + ½ρv² + ρgh = constant → work-energy theorem for fluids.

Q18

The working of an atomizer is based on:

A. Bernoulli’s principle
B. Stokes’ law
C. Surface tension
D. Elasticity

✅ Show Answer & Explanation

Answer: A. Bernoulli’s principle
Explanation: High velocity air creates low pressure, sucking liquid upward.

Q19

The unit of surface tension is:

A. N/m
B. N/m²
C. J/m
D. N·m

✅ Show Answer & Explanation

Answer: A. N/m
Explanation: Surface tension = Force/Length → SI unit: N/m.

Q20

If temperature increases, the surface tension of a liquid:

A. Decreases
B. Increases
C. Remains same
D. First increases then decreases

✅ Show Answer & Explanation

Answer: A. Decreases
Explanation: Increased temperature reduces cohesive forces → surface tension decreases.

Q21

The excess pressure inside a liquid drop of radius R (surface tension T) is:

A. 2T/R
B. 4T/R
C. T/R
D. 3T/R

✅ Show Answer & Explanation

Answer: A. 2T/R
Explanation: For liquid drop (one surface): ΔP = 2T/R.

Q22

Stoke’s law gives viscous force F = 6πηrv. This is valid for:

A. Laminar flow & small sphere
B. Turbulent flow
C. Large Reynolds number
D. All cases

✅ Show Answer & Explanation

Answer: A. Laminar flow & small sphere
Explanation: Valid for low Reynolds number (creeping flow).

Q23

The coefficient of viscosity of a liquid decreases with rise in temperature because:

A. Cohesive force decreases
B. Density increases
C. Volume decreases
D. Molecular speed decreases

✅ Show Answer & Explanation

Answer: A. Cohesive force decreases
Explanation: Increase in temperature reduces cohesive forces, viscosity decreases.

Q24

The ratio of shearing stress to shearing strain is called:

A. Modulus of rigidity
B. Young’s modulus
C. Bulk modulus
D. Poisson’s ratio

✅ Show Answer & Explanation

Answer: A. Modulus of rigidity
Explanation: Shear modulus G = shearing stress / shearing strain.

Q25

The Poisson’s ratio σ is defined as:

A. Lateral strain / longitudinal strain
B. Longitudinal strain / lateral strain
C. Stress / strain
D. Strain / stress

✅ Show Answer & Explanation

Answer: A. Lateral strain / longitudinal strain
Explanation: σ = – (lateral strain)/(longitudinal strain).

Q26

For a perfectly rigid body, Young’s modulus is:

A. Infinity
B. Zero
C. 1
D. Variable

✅ Show Answer & Explanation

Answer: A. Infinity
Explanation: Rigid → no strain for any stress → Y → ∞.

Q27

The length of a wire increases by 0.1% when a stress of 2×10⁷ N/m² is applied. Young’s modulus is:

A. 2×10¹⁰ N/m²
B. 2×10⁹ N/m²
C. 2×10¹¹ N/m²
D. 2×10⁸ N/m²

✅ Show Answer & Explanation

Answer: A. 2×10¹⁰ N/m²
Explanation: Strain = 0.001, Y = stress/strain = 2×10⁷/10⁻³ = 2×10¹⁰ N/m².

Q28

A cube of side 10 cm is subjected to a shearing force of 1000 N. The shearing stress is:

A. 10⁵ N/m²
B. 10⁴ N/m²
C. 10⁶ N/m²
D. 10³ N/m²

✅ Show Answer & Explanation

Answer: A. 10⁵ N/m²
Explanation: Area = 0.01 m², stress = F/A = 1000/0.01 = 10⁵ N/m².

Q29

The pressure at a depth h in a liquid of density ρ is:

A. P₀ + ρgh
B. P₀ – ρgh
C. ρgh
D. P₀ρgh

✅ Show Answer & Explanation

Answer: A. P₀ + ρgh
Explanation: Hydrostatic pressure increases with depth: P = P₀ + ρgh.

Q30

A barometer reads 75 cm of Hg. If the tube is inclined at 30° with vertical, the vertical height of Hg column:

A. 75 cm
B. 86.6 cm
C. 150 cm
D. 37.5 cm

✅ Show Answer & Explanation

Answer: A. 75 cm
Explanation: Vertical height remains same (75 cm) independent of inclination.

Q31

The streamline flow becomes turbulent when Reynolds number exceeds about:

A. 2000
B. 1000
C. 5000
D. 100

✅ Show Answer & Explanation

Answer: A. 2000
Explanation: Re > 2000 → turbulent flow (for pipe flow).

Q32

A spherical ball of radius r falls through a viscous medium with terminal velocity v. If radius becomes 2r, terminal velocity becomes:

A. 4v
B. 2v
C. 8v
D. v/2

✅ Show Answer & Explanation

Answer: A. 4v
Explanation: v_term ∝ r², so double radius → 4v.

Q33

The energy stored per unit volume in a stretched wire is:

A. ½ × stress × strain
B. stress × strain
C. ½ × stress² × Y
D. ½ × Y × strain

✅ Show Answer & Explanation

Answer: A. ½ × stress × strain
Explanation: Elastic potential energy density = ½ × stress × strain.

Q34

The Young’s modulus of a wire is Y. The work done per unit volume to produce strain ε is:

A. ½ Y ε²
B. Y ε²
C. ½ Y ε
D. Y ε

✅ Show Answer & Explanation

Answer: A. ½ Y ε²
Explanation: Work/volume = ½ × stress × strain = ½ Y ε².

Q35

A steel wire of length 2 m and area 1 mm² is stretched by 1 mm. If Y = 2×10¹¹ N/m², the elastic potential energy stored is:

A. 0.1 J
B. 0.2 J
C. 0.05 J
D. 0.5 J

✅ Show Answer & Explanation

Answer: A. 0.1 J
Explanation: U = ½ × F × ΔL = 0.5 × (Y A ΔL/L) × ΔL = 0.1 J.

Q36

A liquid does not wet the solid surface if angle of contact is:

A. > 90°
B. < 90°
C. 0°
D. 90°

✅ Show Answer & Explanation

Answer: A. > 90°
Explanation: θ > 90° → non-wetting (e.g., mercury on glass).

Q37

The rise of liquid in a capillary tube of radius r is h. If radius becomes r/3, the rise becomes:

A. 3h
B. h/3
C. 9h
D. h/9

✅ Show Answer & Explanation

Answer: A. 3h
Explanation: h ∝ 1/r → radius 1/3 → height 3h.

Q38

The SI unit of coefficient of viscosity is:

A. Pa·s
B. N·s/m²
C. kg/(m·s)
D. All of these

✅ Show Answer & Explanation

Answer: D. All of these
Explanation: All represent same: poiseuille (Pa·s).

Q39

An incompressible liquid flows through a pipe of varying cross-section. The velocity at cross-section A₁ is v₁. At A₂ = A₁/2, velocity v₂ is:

A. 2v₁
B. v₁/2
C. 4v₁
D. v₁

✅ Show Answer & Explanation

Answer: A. 2v₁
Explanation: A₁v₁ = A₂v₂ → v₂ = (A₁/A₂)v₁ = 2v₁.

Q40

The pressure difference between two ends of a capillary tube of radius r, length l, carrying fluid of viscosity η at flow rate Q is given by:

A. Poiseuille’s formula
B. Bernoulli’s eq
C. Stokes’ law
D. Continuity eq

✅ Show Answer & Explanation

Answer: A. Poiseuille’s formula
Explanation: ΔP = 8ηlQ/(πr⁴) → Poiseuille’s equation for laminar flow.

Q41

The coefficient of linear expansion α is defined as:

A. ΔL/(L₀ΔT)
B. L₀ΔT/ΔL
C. ΔL/ΔT
D. ΔT/ΔL

✅ Show Answer & Explanation

Answer: A. ΔL/(L₀ΔT)
Explanation: α = (1/L₀)(dL/dT).

Q42

A rod of length L₀ at 0°C expands by ΔL when heated to 100°C. If same rod at 0°C is heated to 200°C, expansion will be:

A. 2ΔL
B. ΔL
C. 4ΔL
D. ΔL/2

✅ Show Answer & Explanation

Answer: A. 2ΔL
Explanation: ΔL ∝ ΔT, so ΔT double → expansion double.

Q43

The apparent expansion of a liquid in a container is γ_app. The real expansion γ_real is:

A. γ_app + γ_vessel
B. γ_app – γ_vessel
C. γ_vessel – γ_app
D. γ_app × γ_vessel

✅ Show Answer & Explanation

Answer: A. γ_app + γ_vessel
Explanation: γ_real = γ_app + γ_vessel (since container also expands).

Q44

The anomalous expansion of water occurs between:

A. 0°C to 4°C
B. 4°C to 10°C
C. 0°C to 10°C
D. -4°C to 0°C

✅ Show Answer & Explanation

Answer: A. 0°C to 4°C
Explanation: Water density maximum at 4°C; expands when cooled from 4°C to 0°C.

Q45

Two rods of same length and material have radii r and 2r. Their Young’s moduli are in ratio:

A. 1:1
B. 1:2
C. 2:1
D. 1:4

✅ Show Answer & Explanation

Answer: A. 1:1
Explanation: Young’s modulus is material property → same for same material.

Q46

A wire of length L and area A is stretched by a force F. If length becomes 2L but area is halved, the stress becomes:

A. Same
B. Double
C. Half
D. Four times

✅ Show Answer & Explanation

Answer: B. Double
Explanation: Stress = F/A, A becomes half → stress doubles.

Q47

The maximum load a wire can withstand without breaking is called:

A. Breaking stress
B. Ultimate stress
C. Elastic limit
D. Yield point

✅ Show Answer & Explanation

Answer: A. Breaking stress
Explanation: Breaking stress = maximum tensile stress a material can withstand.

Q48

The dimensions of bulk modulus are same as:

A. Pressure
B. Force
C. Energy
D. Power

✅ Show Answer & Explanation

Answer: A. Pressure
Explanation: Bulk modulus = stress/strain, same as pressure (ML⁻¹T⁻²).

Q49

A soap bubble of radius R is charged. Its radius will:

A. Increase
B. Decrease
C. Remain same
D. First increase then decrease

✅ Show Answer & Explanation

Answer: A. Increase
Explanation: Repulsive charges on surface expand the bubble.

Q50

The terminal velocity of a steel ball of radius 1 mm in glycerin is 2 cm/s. For radius 2 mm, terminal velocity (same conditions) is:

A. 8 cm/s
B. 4 cm/s
C. 2 cm/s
D. 1 cm/s

✅ Show Answer & Explanation

Answer: A. 8 cm/s
Explanation: v ∝ r² → 2² = 4 times → 8 cm/s.

📚 Complete Set of 50 Properties of Bulk Matter Questions
Elasticity, Fluids, Viscosity, Surface Tension, Thermal Expansion

✅ NEET 2026 Pattern | +4/-1 Marking | Detailed Explanations

📊 50 MCQs covering Elasticity, Fluid Mechanics, Viscosity, Surface Tension, and Thermal Expansion