The ice-point reading on a thermometer scale is found to be \(20^\circ,\) while the steam point is found to be \(70^\circ.\) When this thermometer reads \(100^\circ ,\) the actual temperature is:
1. \(80^\circ~\mathrm{C}\)
2. \(130^\circ~\mathrm{C}\)
3. \(160^\circ~\mathrm{C}\)
4. \(200^\circ~\mathrm{C}\)

Subtopic:  Temperature and Heat |
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The temperature at which the Celsius and Fahrenheit thermometers agree (to give the same numerical value) is:
1. \(-40^\circ\)
2. \(40^\circ\)
3. \(0^\circ\)
4. \(50^\circ\)

Subtopic:  Temperature and Heat |
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Two rods of identical dimensions are joined end-to-end, and the ends of the composite rod are kept at \(0^\circ\mathrm{ C}\) and \(100^\circ\mathrm{ C}\) (as shown in the diagram). The temperature of the joint is found to be \(40^\circ\mathrm{ C}.\) Assuming no loss of heat through the sides of the rods, the ratio of the conductivities of the rods \(K_1/K_2\) is:
                     
1. \(\frac32\)
2. \(\frac23\)
3. \(\frac11\)
4. \(\frac{\sqrt3}{\sqrt2}\)

Subtopic:  Conduction |
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A rod \(\mathrm{A}\) has a coefficient of thermal expansion \((\alpha_A)\) which is twice of that of rod \(\mathrm{B}\) \((\alpha_B)\). The two rods have length \(l_A,~l_B\) where \(l_A=2l_B\). If the two rods were joined end-to-end, the average coefficient of thermal expansion is:
1. \(\alpha_A\)
2. \(\frac{2\alpha_A}{6}\)
3. \(\frac{4\alpha_A}{6}\)
4. \(\frac{5\alpha_A}{6}\)

Subtopic:  Thermal Expansion |
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If the ends of the meter stick are maintained at \(\theta_1\)\(^\circ \text{C}\) and \(\theta_2\)\(^\circ \text{C},\) the temperatures measured at the \(25\) cm and \(80\) cm marks are observed to be \(35^\circ \text{C}\) and \(68^\circ \text{C}\) respectively. Then the temperatures of the left end (\(\theta_1\)\(^\circ \text{C}\)) and the right end (\(\theta_2\)\(^\circ \text{C}\)) are: 
1. \(\theta_{1}=0, ~\theta_{2}=90\)   
2. \(\theta_{1}=10,~\theta_{2}=85\)
3. \(\theta_{1}=20, ~\theta_{2}=80\)
4. \(\theta_{1}=30, ~\theta_{2}=100\)
Subtopic:  Conduction |
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When the temperature difference between a body and its surroundings is \(20\)°C, it loses heat to the surroundings at a rate of \(40\) W. If the temperature difference increases to \(25\)°C, the rate of loss of heat is:
1. \(45\) 2. \(50\) W
3. \(60\) 4. \(80\) W
Subtopic:  Newton's Law of Cooling |
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Two liquids flow through a heat exchanger and exchange heat energy.
The first liquid has a mass flow rate \(\Big(\frac{dm}{dt}\Big)=r_1,\) and its temperature rises by \(\Delta\theta_1.\) For the second liquid, the flow rate \(\Big(\frac{dm}{dt}\Big)=r_2,\) and the temperature fall is \(\Delta\theta_2.\) The ratio of their specific heat capacities is:
1.  \(\frac{\Delta\theta_1}{\Delta\theta_2}\)
2.  \(\frac{r_1}{r_2}\)
3.  \(\frac{r_2\Delta\theta_2}{r_1\Delta\theta_1}\)
4.  \(\frac{r_2\Delta\theta_1}{r_1\Delta\theta_2}\)
Subtopic:  Calorimetry |
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A body cools from \(52^\circ \text{C}\) to \(48^\circ \text{C}\) in \(6\) minutes. How much time will the same body take to cool from \(53^\circ \text{C}\) to \(47^\circ \text{C}?\) Assume cooling is linear with time.
1. \(12\) minutes
2. \(9\) minutes
3. \(8\) minutes
4. \(7\) minutes
Subtopic:  Newton's Law of Cooling |
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A solid at temperature T1, is kept in an evacuated chamber at temperature T2 > T1 . The rate of increase of temperature of the body is proportional to

1. T2 – T1

2.   \(T^2_2 -T^2_1\)n

3.   \(T^3_2 -T^3_1\)

4.   \(T^4_2 -T^4_1\)

Subtopic:  Stefan-Boltzmann Law |
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In a room containing air, heat can go from one place to another:

1. by conduction only
2. by convection only
3. by radiation only
4. by all three modes

Subtopic:  Convection |
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