Thermal Properties of Matter

A cup of coffee cools from \(90^\circ C\) to \(80^\circ C\) in t minutes when the room temperature is \(20^\circ C\). The time taken by the similar cup of coffee to cool from \(80^\circ C\) to \(60^\circ C\) at the same room temperature is :

Given below are two statements:
Statement I: The hot water flows faster than cold water
Statement II: Soap water has higher surface tension as compared to fresh water.
In the light of above statements, choose the correct answer from the options given below

[JEE Main 2025, 23 Jan (Shift 1)]

The temperature of a body in air falls from \(40^\circ C\) to \(24^\circ C\) in 4 minutes. The temperature of the air is \(16^\circ C\). The temperature of the body in the next 4 minutes will be :

Two spherical bodies of same materials having radiii 0.2 m and 0.8 m are placed in same atmosphere. The temperature of the smaller body is 800 K and temperature of the bigger body is 400 K . If the energy radiated from the smaller body is E, the energy radiated from the bigger body is (assume, effect of the surrounding temperature to be negligible),

[JEE Main 2025, 22 Jan (Shift 1)]

Water is used as a coolant in a nuclear reactor because of its:

Given below are two statements:
Statement I: The hot water flows faster than cold water
Statement II: Soap water has higher surface tension as compared to fresh water.
In the light of above statements, choose the correct answer from the options given below

[JEE Main 2025, 23 Jan (Shift 1)]

A cup of coffee take a time ' t' to cool from \(90^{\circ} \mathrm{C}\) to \(80^{\circ} \mathrm{C}\) in a surrounding of \(20^{\circ} \mathrm{C}\). If a similar cup of coffee is cooled from \(80^{\circ} \mathrm{C}\) to \(60^{\circ} \mathrm{C}\) in the same surrounding, it takes a time

(Shift - II Memory Based)

Given below are two statements:
Statement I: The hot water flows faster than cold water
Statement II: Soap water has higher surface tension as compared to fresh water.
In the light of above statements, choose the correct answer from the options given below

[JEE Main 2025, 23 Jan (Shift 1)]

A bullet at \(300\text{ }\text{K}\) hits a wooden block. The melting point is \(600\text{ }\text{K}\), and the total work done is 625 J. If the specific heat capacity is \(0.442\text{ }\text{J/g}{⋅}^{∘}\text{C}\) and the latent heat is \(247\text{ }\text{J/g}\), find the mass of the bullet.(shift 1 Memory based)

A cup of coffee take a time ' t' to cool from \(90^{\circ} \mathrm{C}\) to \(80^{\circ} \mathrm{C}\) in a surrounding of \(20^{\circ} \mathrm{C}\). If a similar cup of coffee is cooled from \(80^{\circ} \mathrm{C}\) to \(60^{\circ} \mathrm{C}\) in the same surrounding, it takes a time

(Shift - II Memory Based)

Temperature of a body reduces from \(40^{\circ}\) to \(24^{\circ} \mathrm{C}\) in 4 minutes in surrounding of \(16^{\circ} \mathrm{C}\). What is the temperature of body after further 4 minutes?

(Shift - II Memory based)

Two spherical bodies of same materials having radiii 0.2 m and 0.8 m are placed in same atmosphere. The temperature of the smaller body is 800 K and temperature of the bigger body is 400 K . If the energy radiated from the smaller body is E, the energy radiated from the bigger body is (assume, effect of the surrounding temperature to be negligible),

[JEE Main 2025, 22 Jan (Shift 1)]

Given below are two statements:
Statement I: The hot water flows faster than cold water
Statement II: Soap water has higher surface tension as compared to fresh water.
In the light of above statements, choose the correct answer from the options given below

[JEE Main 2025, 23 Jan (Shift 1)]

An amount of ice of mass \({10}^{-3}\mathrm{kg}\) and temperature \(-10^\circ \mathrm{C}\) is transformed to vapour of temperature \(110^\circ \mathrm{C}\) by applying heat. The total amount of work required for this conversion is,
(Take, specific heat of ice \(=2100{\mathrm{Jkg}}^{-1}{\mathrm{K}}^{-1}\), specific heat of water \(=4180{\mathrm{Jkg}}^{-1}{\mathrm{K}}^{-1}\), specific heat of steam \(=1920{\mathrm{Jkg}}^{-1}{\mathrm{K}}^{-1}\), Latent heat of ice \(=3.35\times {10}^{5}{\mathrm{Jkg}}^{-1}\) and Latent heat of steam \(=2.25\times {10}^{6}\) \({\mathrm{Jkg}}^{-1}\) )

[JEE Main 2025, 22 Jan (Shift 1)]

The difference of temperature in a material can convert heat energy into electrical energy. To harvest the heat energy, the material should have;

Two spherical black bodies of radii \(0.8\text{ }\text{m}\) and \(0.2\text{ }\text{m}\) are at temperatures of \(400\text{ }\text{K}\) and \(800\text{ }\text{K}\), respectively. Find the ratio of the rate of heat loss from the two bodies.

(Shift I Memory based)

What amount of heat is required to convert \(1\text{ }\text{gm}\) of ice at \(−1{0}^{∘}\text{C}\) into steam at \(11{0}^{∘}\text{C}\)?

(Shift I Memory Based)

Three stars \( A, B, C \) have surface temperatures \( T_{A}, T_{B}, T_{C} \) respectively. Star \(A\) appears bluish, star \(B\) appears reddish and star \(C\) yellowish. Hence,

The quantities of heat required to raise the temperature of two solid copper sphere of radii \( r_{1} \) and \( r_{2}\left(r_{1}=1.5 r_{2}\right) \) through \( 1 \mathrm{~K} \) are in the ratio