By how much the temperature of a copper rod to be raised so as to increase its length by 1% ? Given that coefficient of linear expansion of copper = 1.7 x 10^-5 K^-1 . 

2

(a)

The density of mercury is \(13.6\times { 10 }^{ 3 }Kg\quad { m }^{ -3 }\)  at 0^o C and its coefficient of volume expansion is \(1.82\times { 10 }^{ -4 }{ K }^{ -1 }\)  . Find the density at 50^o C.

2

(a)

What value of temperature in the Celsius and Fahrenheit scales give the same reading?

2

(a)

There is a slight temperature different between the water fall at the top and the bottom. Why?

2

(a)

Given below are observations on molar specific heats at room temperature of some common gases.

Gas	Molar specific heat  (Cv) (cal mol-1K-1)
Hydrogen	4.87
Nitrogen	4.97
Oxygen	5.02
Nitric oxide	4.99
Carbon monoxide	5.01
Chlorine	6.17

The measured molar specific heats of these gases are markedly different from those for monatomic gases. Typically, molar specific heat of a monatomic gas is 2.92 cal/mol K. Explain this difference. What can you infer from the somewhat larger (than the rest) value for chlorine ?

2

(a)

In a coal fire, the pockets formed by coals appear brighter than the coals themselves. Is the temperature of such a pocket higher than the surface temperature of a glowing coal?

2

(a)

Woollen clothes are warm in winter. Why?

2

(a)

How does density of a solid change as it is heated ?

2

(a)

What happens to the phase of water at its critical point?

2

(a)

Express 60°C in ⁰F

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(a)

Tea gets cooled when sugar is added to it. Why?

2

(a)

WiJat is temperature gradient?

2

(a)

The temperature gradient in a rod 0.5 m long is 80°C per metre. The temperature of the hotter end is 30°C What is the temperature of the colder end?

2

(a)

Arrange Cu, Al and Ag in the order of increasing thermal conductivity?

2

(a)

On winter nights, we feel warmer when clouds cover the sky than when the sky is clear, Why ?

2

(a)