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A block of mass 2.5 kg is heated to temperature of 500$°$C and placed on a large ice block. What is the maximum amount of ice that can melt (approx.). Specific heat for the body = 0.1 Cal/gm$°$C.
1. 1 kg
2. 1.5 kg
3. 2 kg
4. 2.5 kg

10 gm of ice at 0$°$C is kept in a calorimeter of water equivalent 10 gm. How much heat should be supplied to the apparatus to evaporate the water thus formed ?(Neglect loss of heat)
1. 6200 cal
2. 7200 cal
3. 13600 cal
4. 8200 cal

A solid material is supplied with a heat at a constant rate. The temperature of material is changing with heat input as shown in the figure. What does slope DE represent 

1. latent heat of liquid
2. latent heat of vapour
3. heat capacity of vapour 
4. inverse of heat capacity of vapour

Find the amount of heat supplied to decrease the volume of an ice water mixture by 1 cm³ without any change in temperature. $\left({\mathrm{\rho }}_{\mathrm{ice}}=0.9, {\mathrm{\rho }}_{\mathrm{water}}, {\mathrm{L}}_{\mathrm{ice}}=80 \mathrm{cal}/\mathrm{gm}\right)$
1. 360 cal
2. 500 cal
3. 720 cal
4. none of these
 

If two rods of length L and 2L having coefficients of linear expansion $\mathrm{\alpha }$ and $2\mathrm{\alpha }$ respectively are connected so that total length becomes 3L, the average coefficient of linear expansion of the composition rod equals :
1. $\frac{3}{2}\mathrm{\alpha }$
2. $\frac{5}{2}\mathrm{\alpha }$
3. $\frac{5}{3}\mathrm{\alpha }$
4. none of these

A thin copper wire of length L increases in length by 1% when heated from temperature ${\mathrm{T}}_1 \mathrm{to} {\mathrm{T}}_2$. What is the percentage change in area when a thin copper plate having dimensions 2L$\times$L is heated from ${\mathrm{T}}_1 \mathrm{to} {\mathrm{T}}_2$ ?
1. 1%
2. 2%
3. 3%
4. 4%

One end of a 2.35 m long and 2.0 cm radius aluminium rod (K = 235 ${\mathrm{Wm}}^{-1}{\mathrm{K}}^{-1}$) is held at 20$°$C. The other end of the rod is in contact with a block of ice at its melting point. The rate in $\mathrm{kg}.{\mathrm{s}}^{-1}$ at which ice melts is 
1. $24\mathrm{\pi }\times {10}^{-6}$
2. $24\mathrm{\pi }\times {10}^{-6}$
3. $2.4\mathrm{\pi }\times {10}^{-6}$
4. $4.8\mathrm{\pi }\times {10}^{-6}$
[ Taking latent heat of fusion for ice as $\frac{10}{3}\times {10}^5 \mathrm{J}.{\mathrm{kg}}^{-1}$]

Four rods of same material with different radii r and length l are used to connect two reservoirs of heat at different temperatures. Which one will conduct most heat ?
1. r = 2 cm, l = 0.5 m
2. r = 2 cm, l = 2 m
3. r = 0.5 cm, l = 0.5 m
4. r = 1 cm, l = 1 m

A wall has two layer A and B each made of different material, both the layers have the same thickness. The thermal conductivity of the material A is twice that of B. Under thermal equilbrium the temperature different across the wall B is 36$°$C. The temperature difference across the wall A is 
1. 6$°$C
2. 12$°$C
3. 18$°$C
4. 72$°$C

Three identical rods AB, CD and PQ are joined as shown. P and Q are mid points of AB and CD respectively. Ends A,B,C and D are maintained at $0°\mathrm{C}, 100°\mathrm{C}, 30°\mathrm{C} \mathrm{and} 60°\mathrm{C}$ respectively. The direction of heat flow in PQ is 

1. from P to Q
2. from Q to P
3. heat does not flow in PQ
4. data not sufficient

A black metal foil is warmed by radiation from a small sphere at temperature 'T' and at a distance 'd'. It is found that the power received by the foil is P. If both the temperature and distance are doubled, the power received by the foil will be :
1. 16 P
2. 4 P
3. 2 P
4. P

The rate of emission fo radiation of a black body at 273$°$C is E, then the rate of emission of emission of radiation of the body at 0$°$C will be 
1. $\frac{\mathrm{E}}{16}$
2. $\frac{\mathrm{E}}{4}$
3. $\frac{\mathrm{E}}{8}$
4. 0

The power radiated by a black body is P and it radiates maximum energy around the wavelength ${\mathrm{\lambda }}_0$. If the temperature of the black body is now changed so that it radiates maximum energy around wavelength 3/4 ${\mathrm{\lambda }}_0$, the power radiated by it will increase by a factor of 
1. 4/3
2. 16/9
3. 64/27
4. 256/81

A black body calorimeter filled with hot water cools from 60$°$C to 50$°$C in 4 min and 40$°$C to 30$°$C in 8 min. The approximate temperature of surrounding is :
1. 10$°$C
2. 15$°$C
3. 20$°$C
4. 25$°$C

The plots of intensity versus wavelength for three black bodies at temperature ${\mathrm{T}}_1,{\mathrm{T}}_2 \mathrm{and} {\mathrm{T}}_3$ respectively are as shown. Their temperatures are such that 

1. ${\mathrm{T}}_1>{\mathrm{T}}_2>{\mathrm{T}}_3$
2. ${\mathrm{T}}_1>{\mathrm{T}}_3>{\mathrm{T}}_2$
3. ${\mathrm{T}}_2>{\mathrm{T}}_3>{\mathrm{T}}_1$
4. ${\mathrm{T}}_3>{\mathrm{T}}_2>{\mathrm{T}}_1$

2 litre water at 27$°$C is heated by a 1 kW heater in an open container. On an average heat is lost to surroundings at the rate 160 J/s. The time required for the temperature to reach 77$°$C is 
1. 8 min 20 sec
2. 10 min
3. 7 min 
4. 14 min

In which of the following phenomenon heat convection does not take place
1. land and sea breeze
2. boiling of water
3. heating of glass surface due to filament of the bulb
4. air around the furnace

A spherical body of area A, and emissivity e = 0.6 is kept inside a black body. What is the rate at which energy is radiated per second at temperature T
1. 0.6 $\mathrm{\sigma } {\mathrm{AT}}^4$
2. 0.4 $\mathrm{\sigma } {\mathrm{AT}}^4$
3. 0.8 $\mathrm{\sigma } {\mathrm{AT}}^4$
4. 1.0 $\mathrm{\sigma } {\mathrm{AT}}^4$