A metallic bar of Young's modulus \(0.5 \times 10^{11}~\text{Nm}^{-2},\)  coefficient of linear thermal expansion \(10^{-5} ~^{\circ}\text{C}^{-1},\) length \(1~\text m\) and cross-sectional area \(10^{-3} ~\text{m}^2\) is heated from \(0^\circ \text{C}\) to \(100^\circ \text C\) without expansion or bending. The compressive force developed in the metallic bar is: 
1. \(50 \times 10^3~ \text N\)
2. \(100 \times 10^3 ~\text N\)
3. \(2 \times 10^3~\text N\)
4. \(5 \times 10^3 ~\text N\)

Subtopic:  Thermal Stress |
 73%
From NCERT
NEET - 2024
Please attempt this question first.
Hints
Please attempt this question first.

Two rods, one made of copper and the other made of steel, of the same length and same cross-sectional area are joined together. The thermal conductivity of copper and steel are \(385~\text{Js}^{-1}\text{K}^{-1}\text{m}^{-1}\) and \(50~\text{Js}^{-1}\text{K}^{-1}\text{m}^{-1}\) respectively. The free ends of copper and steel are held at \(100^\circ \text{C}\) and \(0^\circ \text{C}\) respectively. The temperature at the junction is, nearly:
1. \(12^\circ \text{C}\)
2. \(50^\circ \text{C}\)
3. \(73^\circ \text{C}\)
4. \(88.5^\circ \text{C}\)
Subtopic:  Conduction |
 72%
From NCERT
NEET - 2022
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A cup of coffee cools from \(90^{\circ}\text{C}\) to \(80^{\circ}\text{C}\) in \(t\) minutes, when the room temperature is \(20^{\circ}\text{C}.\) The time taken by a similar cup of coffee to cool from \(80^{\circ}\text{C}\) to \(60^{\circ}\text{C}\) at room temperature same at \(20^{\circ}\text{C}\) is:
1. \(\frac{10}{13}t\) 
2. \(\frac{5}{13}t\)
3. \(\frac{13}{10}t\)
4. \(\frac{13}{5}t\)

Subtopic:  Newton's Law of Cooling |
 63%
From NCERT
NEET - 2021
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

The diagram below shows a graphical representation of pressure versus temperature variation for three different low-density gases A, B & C.

Which of the following can be deduced about absolute zero for the gases A, B & C:

1. Different for all the three gases

2. Same only for gases A & B 

3. Same only for gases B & C

4. Same for all the three gases

 

 

 

Subtopic:  Temperature and Heat |
 79%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The figure shows pressure versus temperature graph for a low-density gas kept in a vessel with:

 

1. Variable volume

2. Volume first increasing then decreasing

3. Volume first decreasing then increasing

4. Constant volume

Subtopic:  Temperature and Heat |
 68%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The given graph shows the variation of Fahrenheit temperature (tF) vs Celsius temperature (tC). The correct relation between the two temperature scales that can be deduced from the graph below is

1. tFtC=59
2. tF-32tC=212-32100-0
3. tF-32tC=100-0212-32
4. tFtC=212-32100-0

Subtopic:  Temperature and Heat |
 77%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

An iron bar \(\left(L_{1} = 0 . 1 ~ \text{m},   A_{1} =  0 . 02 ~\text{m}^{2}, K_{1} = 79~\text{W m}^{- 1} \text{K}^{- 1}\right)\) and a brass bar \(\left(L_{2}= 0 . 1 ~\text{m}, A_2 = 0.02~\text{m}^2, K_2 = 109~\text{W m}^{-1}\text{K}^{-1}\right)\) are soldered end to end as shown in the figure. The free ends of the iron bar and brass bar are maintained at \(373\) K and \(273\) K respectively. The heat current through the compound bar is:

1. \(916.1\) W
2. \(826.1\) W
3. \(926.1\) W
4. \(726\) W

Subtopic:  Conduction |
 63%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

An iron bar \(K_1 = 79~\text{W m}^{-1}\text{K}^{-1}\) and a brass bar \(K_2 = 109~\text{W m}^{-1}\text{K}^{-1}\) are soldered end to end as shown in the figure. The free ends of the iron bar and brass bar are maintained at \(373\) K and \(273\) K respectively. Then the equivalent thermal conductivity of the compound bar is:

1. \(94.6~\text{W m}^{-1}\text{K}^{-1}\) 2. \(93.6~\text{W m}^{-1}\text{K}^{-1}\)
3. \(81.6~\text{W m}^{-1}\text{K}^{-1}\) 4. \(91.6~\text{W m}^{-1}\text{K}^{-1}\)
Subtopic:  Conduction |
 63%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A pan filled with hot food cools in \(2\) minutes from \(94^{\circ}\text{C}\) to \(86^{\circ}\text{C}\) when the room temperature is \(20^{\circ}\text{C}\). How long will it take to cool from \(71^{\circ}\text{C}\) to \(69^{\circ}\text{C}\)?
1. \(50\) s
2. \(52\) s
3. \(42\) s
4. \(48\) s

Subtopic:  Newton's Law of Cooling |
 79%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

An iron bar \(\left(L_{1}=0.1 \text{m} ,   A_{1}=0.02~\text{m}^{2} ,   K_{1}=79~\text{Wm}^{- 1}   \text{K}^{-1}\right)\) and a brass bar \(\left(L_{2}=0.1~\text{m} , A_{2}=0.02~\text{m}^{2} , K_{2}=109~\text{Wm}^{- 1}  \text{K}^{- 1}\right)\) are soldered end to end as shown in the figure. The free ends of the iron bar and brass bar are maintained at \(373~ \text{K}\) and \(273~ \text{K}\) respectively. The temperature of the junction of the two bars is:
           
  

1. \(215~ \text{K}\) 
2. \(315~ \text{K}\) 
3. \(415~ \text{K}\) 
4. \(115~ \text{K}\)

Subtopic:  Conduction |
 79%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch