Take 2kg of ice is at -`5^@` C. Supply heat is continuously to ice. Till it starts boiling. Note the temperature every minute. Draw a graph between temperature and time using the values you get. What do you understand from the graph. Write the conclusions. ( You know that ice melts at`0^@ `c and boils at `l00^@C`

A cube of iron (density = 8000kg m^(-1) , specific heat capacity = 470g J kg^(-1)K^(-1) ) is heated to a high temperature and is placed on a larger block of ice at 0^(@)C . The cube melts the ice below it, displaces the water and sinks in the final equilibrium position its upper surface is just inside the ice. Calculate the initial temperature of the cube. Neglect any loss of heat outside the ice and the cube .The density of ice = 900 kg m^(-1) and the latent heat of fusion of ice = 3.36 xx 10^(5)J kg^(-1)

Figure shows water in a container having 2.0-mm thick walls made of a material of thermal conductivity 0.50Wm^(-1)C^(-1) . The container is kept in a melting-ice bath at 0^(@)C . The total surface area in contact with water is 0.05m^(2) . A wheel is clamped inside the water and is coupled to a block of mass M as shown in the figure. As the goes down, the wheel rotates. It is found that after some time a steady state is reached in which the block goes down with a constant speed of 10cms^(-1) and the temperature of the water remains constant at 1.0^(@)C .Find the mass M of the block. Assume that the heat flow out of the water only through the walls in contact. Take g=10ms^(-2) .

An electric kettle used to prepare tea, takes 2 minutes to boil 4 cups of water (1 cup contains 200 cc of water) if the room temperature is 25^@ C , (a) If the cost of power consumption is Re 1.00 per unit (1 unit = 1000 watt-hour) , calculate the cost of boiling 4 cups of water. (b) What will be the correspoinding cost if the room temprature drops to 5^@ C ?

A heating element using nichrome connected to a 230V supply draws an initial current of 3.2 A which settles after a few seconds to steady value of 2.8 A. What is the steady temperature of the heating element if room temperature is 27.0^(@)C ? Temperature coefficient of resistance of nichrome averaged over the temperature range involved is 1.70xx10_(-4)

Plot the points A(1,0), B(-7,2),C(-3,7) on a graph sheet and join them to form a triangle. Plot the point G(-3,3). Join AG and extend it to intersect BC at D. Join BG and extend it to intersect AC at E. What do you infer when you measure the distance between BD and DC and the distance between CE and EA? Using distance formula find the lengths of CG and GF, where F in on AB. Write your inference about AG:GD, BG:GE and CG:GF,

Answer the following questions . a. The earth's magnetic field varies from point is space. Does it also change with time ? It so , on what time scate does it change appreciably ? b. The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism why ? c. The charged currents in the outer conducting regions of the earth's core are thought to be responsible for earth's magnetism . What might be the ' battery ' (i.e., the source of energy) to sustain these currents ? d. The earth may have even reversed the direction of its field several times during its history of 4 to 5 billion years. How can geologists know about the earth's field in such distant past ? e. The earth's field departs from its dipole substantially at large distances (greater than about 30,000 km) what agencies may be responsible for this distortion ? f. Interstellar space has an extremely weak magnetic field of the order of 10^(-12) T, Can such a weak field be of any significant consequence ? Explain. [Note : Exercise 2 is meant mainly to arouse your curiosity . Answers to some question above are tentative or unknown . Brief answers wherever possible are given at the end . For details , you should consult a good text on geomagnetism.]

Water is a universal slvent. But alcohol also dissolves most of the substances soluble in water and also many more. Boiling point of water is 100^(@)C and that of alcohol is 80^(@)C. The specific heat of water is much higher than the specific heat of alcohol. (a) List out three possible differences if instead of water as teh liquid in our body we had alcohol. (b) What value can you derive from this special property of water and its innumerable uses in sustaining life on earth ?

A piece of ice of mass of 100g and at temperature 0^(@)C is put in 200g of water of 25^(@) How much ice will melt as the temperature of the water reaches 0^(@)C ? The specific heat capacity of water = 4200 J kg ^(-1)K^(-1) and the latent heat of ice = 3.36 xx 10^(5)J kg^(-1)

One end of a steel rod (K=46Js^(-1)m^(-1)C^(-1)) of length 1.0m is kept in ice at 0^(@)C and the other end is kept in boiling water at 100^(@)C . The area of cross section of the rod is 0.04cm^(2) . Assuming no heat loss to the atmosphere, find the mass of the ice melting per second. Latent heat of fusion of ice =3.36xx10^(5)Jkg^(-1) .