One kilogram of ice at 0°C is mixed with one kilogram of water at 80°C. The final temperature of the mixture is (Take: Specific heat of water = 4200 J kg-1C-1, Latent heat of ice = 336 kJ kg-1)

1. 0°C
2. 50°C
3. 40°C
4. 60°C

Subtopic:  Calorimetry |
 66%
Level 2: 60%+
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The fastest mode of heat transfer is 

1.  Conduction

2.  Radiation

3.  Convection

4.  all are  equally fast

Subtopic:  Radiation |
 71%
Level 2: 60%+
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A temperature of \(100^{\circ}\text {F}\) (Fahrenheit scale) is equal to \(T~\text{K}\) (Kelvin scale). The value of \(T\) is:
1. \(310.9\)
2. \(37.8\)
3. \(100\)
4. \(122.4\)

Subtopic:  Temperature and Heat |
 75%
Level 2: 60%+
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A black body at temperature \(300~\text{K}\) radiates heat at the rate \(E\). If its temperature is increased to \(900~\text{K}\), the rate of radiation will increase to:
1. \(16E\)
2. \(64E\)
3. \(81E\)
4. \(256E\)

Subtopic:  Radiation |
Level 3: 35%-60%
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A body cools down from \(80^{\circ}\mathrm{C}\) to \(70^{\circ}\mathrm{C}\) in 5 minutes. The temperature of the same body will fall from \(70^{\circ}\mathrm{C}\) to \(60^{\circ}\mathrm{C}\) in:

1. less than 5 minutes.
2. equal to 5 minutes.
3. more than 5 minutes.
4. can't say anything as the temperature of the surroundings is not known.

Subtopic:  Newton's Law of Cooling |
 63%
Level 2: 60%+
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If \(\lambda_m\) is the wavelength, corresponding to which the radiant intensity of a block is at its maximum and its absolute temperature is \(T,\) then which of the following graphs correctly represents the variation of \(T?\)

1. 2.
3. 4.
Subtopic:  Wien's Displacement Law |
 75%
Level 2: 60%+
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Heat capacity is equal to the product of:

1.  mass and gas constant

2.  mass and specific heat

3.  latent heat and volume of water

4.  mass and Avogadro number

 

Subtopic:  Calorimetry |
 90%
Level 1: 80%+
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When a block of iron floats in Hg at 0°C, a fraction K1 of its volumen= is submerged, while at temperature of 60°C a fraction K2 is seen to be submersed. If the coefficient of volume expansion of iron is γFe and that of mercury is γHg, then the ratio K1K2 can be expressed as:

1. 1+60γFe1+60γHg

2. 1-60γFe1+60γHg

3. 1+60γFe1-60γHg

4. 1+60γHe1-60γFe

Subtopic:  Thermal Expansion |
 50%
Level 3: 35%-60%
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Hot water cools from 60°C to 50°C in first 10 minutes and from 50°C to 42°C in next 10 minutes. The temperature of surrounding is :

1.  5°C

2.  10°C

3.  15°C

4.  20°C

 

Subtopic:  Newton's Law of Cooling |
 76%
Level 2: 60%+
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A pendulum clock runs faster by \(5\) s per day at \(20^{\circ}\mathrm {C}\) and goes slow by \(10\) s per day at \(35^{\circ}\mathrm {C}\). It shows the correct time at a temperature of:
1. \(27.5^{\circ}\mathrm {C}\)
2. \(25^{\circ}\mathrm {C}\)
3. \(30^{\circ}\mathrm {C}\)
4. \(33^{\circ}\mathrm {C}\)

Subtopic:  Thermal Expansion |
 67%
Level 2: 60%+
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