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 $k{g}^{-1}{C}^{-1}$, Latent heat of ice = 336 kJ $k{g}^{-1}$)

1. $0°$C
2. $50°C$
3. $40°C$
4. $60°C$

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

Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is at ${100}^{°}$ C, while the other one is at $0^{°<mspace\; width="1em"></mspace>}$C. If the two bodies are brought into contact, then assuming no heat loss, the final common temperature is -

1. ${50}^{°}<mspace\; width="1em"></mspace>C$

2. more than ${50}^{°}$C

3. less than ${50}^{°}$C but greater than $0^{°}$C

4.  $0<mspace\; width="1em"></mspace>{}_{0}C$

Steam at 100°C is passed into 20 g of water at 10°C. When water acquires a temperature of 80°C, the mass of water present will be (Take specific heat of water=1 cal g^-1 °C^-1 and latent heat of steam = 540 cal g^-1)

1. 24 g                       

2. 31.5g

3. 42.5 g                   

4. 22.5 g

Liquid oxygen at 50K is heated to 300K at constant pressure of 1 atm. The rate of heating is constant Which one of the following graphs represents the variation of temperature with time?
1. 
2. 
3. 
4.