1. 2 chunks of metal with heat capacities C1 & C2 are interconnected by a rod of lenght L and cross-sectional are S & fairly low heat conductivity k . the whole system is thermelly insulated from the environment . At a moment t = 0 the temperature difference b/w the two chunks of metal equals ( T)o(o is on foot)

assuming the heat capacity of the rod to be negligible, find the temperatrure difference as a function of time..

 

 

2. a constant electric current flows along a uniform wire with cross-sectional radius R & heat conductivity coefficient k . a unit volume of the wire generates a thermal power  . find the temperature difference across the wire provided the steady - state temperature at the wire surface is equal to To

 

 

 

 3.  if one mole of a monoatomic gas(= 5/3) is mixed with one mole of a diatomic gas(=7/5) the value of  for the mixture is??

 

 

4. 2 perfect gases at absolute temperatures t1 & t2 are  mixed. find the temperature of the mixture if masses of molecules are m1&m2 and the number of molecules in the gases are n1&n2 respectively.

 

 

5.three rods of material X and three rods of material Y are connected as shown in fig. All the rods are of identical length and cross-sectional area. If A & E is maintained at 60 & 10 degree C calculate the temperatures of the junctions B,C,D. K for X and Y  is 0.92 and 0.46 cal/degree C/s/cm

 

 

 

6.the U -tube of uniform cross-section contains mercury to the depth shoen. The left side of the cube is closed at the top and the right side is connected to a good vaccum pump(i.e. pressure is made 0). the temperature of air in the closed tube is raised from 27 to 111 degree C how far the level of mercury falls on the left side???

these are mind blowing

 

Q3)

C_vmix =(n₁C_v1 + n₂C_v2)/n₁+n₂

        = 2R

therefore C_pmix = 2R + R = 3R

1)

There is a similar worked example in HC Verma in page no. 93 Q.no.12

 

Do have a look at it and tell me if you have any doubts

 

6)

Use Charles and volume V=AL

 

Here V₁=50A  T₁=300K    V₂=XA     T₂=384K    where A is area of cross section

 

Using V₁/T₁=V₂/T₂

 

We get X=64cm

 

So the mercury level falls by 14cm