JEE Physics Thermal Properties Of Matter MCQs Set 18

Multiple Choice Questions (MCQs) for JEE Physics: Thermal Properties Of Matter

Explore reliable objective questions for Thermal Properties Of Matter tailored for JEE learners. Utilizing these Physics multiple-choice formats ensures thorough preparation and strengthens problem-solving speed for upcoming school assessments.

Practice Thermal Properties Of Matter MCQs for JEE Physics

View or download the dedicated Thermal Properties Of Matter MCQ resource below. Practicing these 50 objective questions regularly builds familiarity with standard exam patterns and helps secure higher marks in final Physics evaluations.

Multiple Choice Questions

Question 1: When water is heated from 0°C to 4°C, its volume
(a) increases
(b) decreases
(c) does not change
(d) first decreases and then increases
Show Answer & Explanation

Answer: (b) decreases

Explanation:
1. Water shows anomalous expansion between 0°C and 4°C.
2. Its volume decreases and its density reaches a maximum at 4°C.

Teacher's Note:
1. Maximum density at 4°C.

Question 2: The phenomenon of refreezing of water into ice on removing the increased pressure is called
(a) freezing
(b) fusion
(c) sublimation
(d) regelation
Show Answer & Explanation

Answer: (d) regelation

Explanation:
1. Under pressure ice melts, and when the pressure is removed it freezes again.
2. This is regelation.

Teacher's Note:
1. Regelation.

Question 3: A glass flask is filled up to a mark with 50 cc of mercury at 18°C. If the flask and contents are heated to 38°C, how much mercury will be above the mark? (α for glass is 9 × 10⁻⁶ /°C and the coefficient of real expansion of mercury is 180 × 10⁻⁶ /°C)
(a) 0.85 cc
(b) 0.46 cc
(c) 0.153 cc
(d) 0.05 cc
Show Answer & Explanation

Answer: (c) 0.153 cc

Explanation:
1. Apparent expansion coefficient = γ_Hg − 3α_g = 180 × 10⁻⁶ − 27 × 10⁻⁶ = 153 × 10⁻⁶ /°C.
2. ΔV = 50 × 153 × 10⁻⁶ × 20 = 0.153 cc.

Teacher's Note:
1. Subtract the container's expansion.

Question 4: A bubble of n mole of helium is submerged at a certain depth in water. The temperature of the water increases by Δt°C. How much heat is added approximately to helium during expansion?
(a) \( nC_v\Delta t \)
(b) \( \frac{nC_p}{\Delta t} \)
(c) \( \frac{n^2C_v}{\Delta t} \)
(d) \( nC_p\Delta t \)
Show Answer & Explanation

Answer: (d) \( nC_p\Delta t \)

Explanation:
1. The bubble stays at the pressure of the surrounding water, which remains nearly constant at that depth.
2. So the process is isobaric and Q = nC_pΔt.

Teacher's Note:
1. Constant pressure means C_p.

Question 5: Consider the following statements and select the correct statement(s). I. Copper is a better conductor of heat than glass. II. Silver is the best conductor of heat. III. The thermal conductivity of steel is greater than that of copper.
(a) I only
(b) II only
(c) I and II
(d) II and III
Show Answer & Explanation

Answer: (c) I and II

Explanation:
1. Copper conducts far better than glass, and silver is the best metallic conductor.
2. Steel conducts less than copper, so III is false.

Teacher's Note:
1. Silver is best, then copper.

Question 6: A certain quantity of water cools from 70°C to 60°C in the first 5 minutes and to 54°C in the next 5 minutes. The temperature of the surroundings is
(a) 45°C
(b) 20°C
(c) 42°C
(d) 10°C
Show Answer & Explanation

Answer: (a) 45°C

Explanation:
1. Newton's law: 10/5 = k(65 − T₀) and 6/5 = k(57 − T₀).
2. (65 − T₀)/(57 − T₀) = 10/6 gives T₀ = 45°C.

Teacher's Note:
1. Use the mean temperatures.

Question 7: In a room where the temperature is 30°C, a body cools from 61°C to 59°C in 4 minutes. The time (in minutes) taken by the body to cool from 51°C to 49°C will be
(a) 8
(b) 5
(c) 6
(d) 4
Show Answer & Explanation

Answer: (c) 6

Explanation:
1. The mean excess is 60 − 30 = 30°C in the first case and 50 − 30 = 20°C in the second.
2. The time is inversely proportional to the excess: t = 4 × 30/20 = 6 min.

Teacher's Note:
1. Time is inversely proportional to the excess temperature.

Question 8:
Assertion (A): Specific heat capacity is the cause of the formation of land and sea breeze.
Reason (R): The specific heat of water is more than that of land.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. Land heats faster than water in the day because water's specific heat is larger.
2. The temperature difference drives the breeze, so the reason explains the assertion.

Teacher's Note:
1. High c_water moderates temperature.

Question 9: Heat is transmitted from a higher to a lower temperature through actual mass motion of the molecules in
(a) conduction
(b) convection
(c) radiation
(d) none of these
Show Answer & Explanation

Answer: (b) convection

Explanation:
1. In convection the heated fluid itself moves and carries heat.
2. Conduction passes energy without bulk motion.

Teacher's Note:
1. Convection involves bulk motion.

Question 10: The value of molar heat capacity at constant temperature is
(a) zero
(b) infinity
(c) unity
(d) 4.2
Show Answer & Explanation

Answer: (b) infinity

Explanation:
1. C = ΔQ/(nΔT).
2. In an isothermal process ΔT = 0 while heat flows, so C is infinite.

Teacher's Note:
1. ΔT = 0 gives C → ∞.

Question 11:
Assertion (A): In insulators, electrons do not contribute to their conductivity.
Reason (R): In insulators, no free electrons are present, so they cannot conduct heat.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. Conduction of heat in metals is mainly through free electrons.
2. An insulator has none, so electrons do not contribute.

Teacher's Note:
1. Free electrons carry heat in metals.

Question 12: A body cools from 50.0°C to 49.9°C in 5 s. How long will it take to cool from 40.0°C to 39.9°C? Assume the temperature of the surroundings to be 30.0°C and Newton's law of cooling to be valid
(a) 2.5 s
(b) 10 s
(c) 20 s
(d) 5 s
Show Answer & Explanation

Answer: (b) 10 s

Explanation:
1. The cooling rate ∝ (mean temperature − surroundings).
2. First case: excess ≈ 19.95°C; second: ≈ 9.95°C.
3. The time is inversely proportional to the excess, so t = 5 × 19.95/9.95 ≈ 10 s.

Teacher's Note:
1. Newton's law of cooling.

Question 13: The mass of water which absorbs or emits the same amount of heat as is done by the body for the same rise or fall in temperature is known as
(a) thermal capacity of the body
(b) specific heat capacity of the body
(c) latent heat capacity of the body
(d) water equivalent of the body
Show Answer & Explanation

Answer: (d) water equivalent of the body

Explanation:
1. This is the definition of water equivalent.
2. W = ms (in the CGS system with c_water = 1).

Teacher's Note:
1. Water equivalent W = ms.

Question 14: The triple point of water is
(a) 273.16°F
(b) 273.16 K
(c) 273.16°C
(d) 273.16 R
Show Answer & Explanation

Answer: (b) 273.16 K

Explanation:
1. The triple point of water is defined as 273.16 K (0.01°C).
2. It is the fixed point of the Kelvin scale.

Teacher's Note:
1. Fixed point of the Kelvin scale.

Question 15: On observing light from three different stars P, Q and R, it was found that the intensity of violet colour is maximum in the spectrum of P, the intensity of green colour is maximum in the spectrum of R and the intensity of red colour is maximum in the spectrum of Q. If T_P, T_Q and T_R are the respective absolute temperatures of P, Q and R, then it can be concluded from the above observations that
(a) \( T_P \gt T_R \gt T_Q \)
(b) \( T_P \lt T_R \lt T_Q \)
(c) \( T_P \lt T_Q \lt T_R \)
(d) \( T_P \gt T_Q \gt T_R \)
Show Answer & Explanation

Answer: (a) \( T_P \gt T_R \gt T_Q \)

Explanation:
1. By Wien's law λ_m T = constant.
2. Violet has the shortest wavelength (hottest P), then green (R), then red (coolest Q): T_P > T_R > T_Q.

Teacher's Note:
1. Shorter peak wavelength means higher temperature.

Question 16: Match Column I and Column II.
Column IColumn II
(A) PV = μRT(1) Molar specific heat
(B) γ = 3α(2) Newton's law of cooling
(C) C = (1/μ)(ΔQ/ΔT)(3) Ideal gas equation
(D) dQ/dt = −k(T₂ − T₁)(4) Coefficient of expansion

(a) A-3, B-1, C-4, D-2
(b) A-3, B-4, C-2, D-1
(c) A-3, B-2, C-1, D-4
(d) A-3, B-4, C-1, D-2
Show Answer & Explanation

Answer: (d) A-3, B-4, C-1, D-2

Explanation:
1. PV = μRT is the ideal gas equation (A-3).
2. γ = 3α relates the expansion coefficients (B-4).
3. C = (1/μ)ΔQ/ΔT is the molar specific heat (C-1).
4. dQ/dt = −k(T₂ − T₁) is Newton's law of cooling (D-2).

Teacher's Note:
1. Match each formula with its name.

Question 17: The latent heat of vaporization of a substance is always
(a) greater than its latent heat of fusion
(b) greater than its latent heat of sublimation
(c) equal to its latent heat of sublimation
(d) less than its latent heat of fusion
Show Answer & Explanation

Answer: (a) greater than its latent heat of fusion

Explanation:
1. Vaporization needs a much bigger separation of molecules than melting.
2. For example L_v = 540 cal/g for water compared with L_f = 80 cal/g.

Teacher's Note:
1. L_v > L_f.

Question 18: Which of the following statements is/are false about modes of heat transfer? I. In radiation, heat is transferred from one medium to another without affecting the intervening medium. II. Radiation and convection are possible in vacuum while conduction requires a material medium. III. Conduction is possible in solids while convection occurs in liquids and gases.
(a) I only
(b) II only
(c) I and III
(d) II and III
Show Answer & Explanation

Answer: (b) II only

Explanation:
1. Convection needs a fluid medium, so it is not possible in a vacuum; II is false.
2. I and III are correct.

Teacher's Note:
1. Only radiation works in vacuum.

Question 19:
Assertion (A): A beaker completely filled with water at 4°C will overflow both when heated and when cooled.
Reason (R): There is expansion of water below and above 4°C.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. The volume of water is minimum at 4°C.
2. It expands when cooled below 4°C and when heated above 4°C, so water overflows in both cases.

Teacher's Note:
1. Minimum volume at 4°C.

Question 20:
Assertion (A): The melting point of ice decreases with an increase of pressure.
Reason (R): Ice contracts on melting.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Explanation:
1. By Le Chatelier's principle, a substance that contracts on melting has a lower melting point under pressure.
2. Ice contracts on melting, so the reason explains the assertion.

Teacher's Note:
1. Ice is denser as water.

Question 21:
Assertion (A): Melting of a solid causes no change in internal energy.
Reason (R): Latent heat is the heat required to melt a unit mass of solid.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Show Answer & Explanation

Answer: (d) A is false, but R is true.

Explanation:
1. The latent heat absorbed during melting increases the internal energy (potential energy of molecules) at constant temperature.
2. So the assertion is false and the reason is a true definition.

Teacher's Note:
1. Heat absorbed raises internal energy.

Question 22: The temperature of the two outer surfaces of a composite slab, consisting of two materials having coefficients of thermal conductivity K and 2K and thicknesses x and 4x respectively, are T₂ and T₁ (T₂ > T₁). The rate of heat transfer through the slab in steady state is [A(T₂ − T₁)K/x] f, with f equal to
(a) 2/3
(b) 1/2
(c) 1
(d) 1/3
Show Answer & Explanation

Answer: (d) 1/3

Explanation:
1. The thermal resistances add: R = x/KA + 4x/2KA = 3x/KA.
2. Rate = (T₂ − T₁)/R = A(T₂ − T₁)K/(3x), so f = 1/3.

Teacher's Note:
1. Series resistances add.

Question 23: A hammer of mass 1 kg moving with a speed of 50 m/s hits an iron nail of mass 200 g. If the specific heat of iron is 0.105 cal/g°C and half the energy is converted into heat, the rise in temperature of the nail is (1 cal = 4.2 J)
(a) 7.1°C
(b) 9.2°C
(c) 10.5°C
(d) 12.1°C
Show Answer & Explanation

Answer: (a) 7.1°C

Explanation:
1. Heat = ½ × ½ × 1 × 50² = 625 J.
2. mc = 200 × 0.105 × 4.2 = 88.2 J/°C.
3. ΔT = 625/88.2 = 7.1°C.

Teacher's Note:
1. Convert calories to joules.

Question 24: The value of the coefficient of volume expansion of glycerine is 5 × 10⁻⁴ K⁻¹. The fractional change in the density of glycerine for a rise of 40°C in its temperature is
(a) 0.020
(b) 0.025
(c) 0.010
(d) 0.015
Show Answer & Explanation

Answer: (a) 0.020

Explanation:
1. Δρ/ρ = γΔT = 5 × 10⁻⁴ × 40.
2. = 0.020.

Teacher's Note:
1. Density change is the negative of volume change.

Question 25: Consider the following statements and select the incorrect statements. I. Water expands on heating between 0°C and 4°C. II. The density of water is minimum at 4°C. III. The density of water increases on heating above 4°C. IV. Water contracts on heating between 0°C and 4°C.
(a) III and IV only
(b) I and II only
(c) I, II and III
(d) I, II, III and IV
Show Answer & Explanation

Answer: (c) I, II and III

Explanation:
1. Between 0°C and 4°C water contracts on heating, so I is false and IV is true.
2. The density is maximum at 4°C, so II is false.
3. Above 4°C the density decreases on heating, so III is false.

Teacher's Note:
1. Anomalous expansion of water.

Free study material for Physics

Thermal Properties Of Matter Objective Questions & Solutions for JEE Physics

Download Multiple Choice Questions: Thermal Properties Of Matter (JEE Physics)

Explore reliable practice questions for Thermal Properties Of Matter tailored for JEE Physics learners. Use these multiple-choice formats to evaluate preparedness and strengthen problem-solving skills.

Concept Clarification for Thermal Properties Of Matter

Cross-reference your completed choices with comprehensive NCERT solutions for JEE Physics to ensure absolute clarity across all sub-topics in this chapter.

Additional Study Resources for JEE Physics

Wrap up your chapter revision by testing your knowledge against standard question formats. Everything on our platform is provided free of charge.

FAQs

Where can I access latest JEE Physics Thermal Properties Of Matter MCQs Set 18?

You can get most exhaustive JEE Physics Thermal Properties Of Matter MCQs Set 18 for free on StudiesToday.com. These MCQs for JEE Physics are updated for the 2026-27 academic session as per JEE examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Physics JEE material?

Yes, our JEE Physics Thermal Properties Of Matter MCQs Set 18 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the JEE paper is now competency-based.

How do practicing Physics MCQs help in scoring full marks in JEE exams?

By solving our JEE Physics Thermal Properties Of Matter MCQs Set 18, JEE students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Physics.

Do you provide answers and explanations for JEE Physics Thermal Properties Of Matter MCQs Set 18?

Yes, Physics MCQs for JEE have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused JEE exams.

Can I practice these Physics JEE MCQs online?

Yes, you can also access online interactive tests for JEE Physics Thermal Properties Of Matter MCQs Set 18 on StudiesToday.com as they provide instant answers and score to help you track your progress in Physics.