Three containers C 1 , C 2 a n d C 3 have water at different temperatures. The table below shows the final temperature T when different amounts of water (given in liters) are taken from each container and mixed (assume no loss of heat during the process) The value of θ (in 0 C to the nearest integer) is ———–

A body cools in a surrounding which is at a constant temperature of θ 0 . Assume that it obeys Newton’s law of cooling. Its temperature θ is plotted against time t. Tangents are drawn to the curve at the points P θ = θ 2 and Q θ = θ 1 . These tangents meet the time axis at angles of ϕ 2 and ϕ 1 , as

A body cools down from 60°C to 55°C in 30 s. Using Newton’s law of cooling, calculate the approximate time taken by same body to cool down from 5 5°C to 50°C. Assume that the temperature of surroundings is 45°C.

Two different wires having length L 1 and L 2 and respective temperature coefficient of linear expansion α 1 and α 2 ,are joined end-to-end. Then the effective temperature coefficient of linear expansion is:

Two rods of different materials having coefficients of linear expansion α 1 , α 2 and Young’s moduli Y 1 and Y 2 , respectively, are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If α 1 : α 2 = 2 : 3 , the thermal stresses developed in the two rods are equally provided, Y 1 : Y 2 is equal to

If there are no heat losses, the heat released by the condensation of x gm of steam at 100 o C into water at 100oC can be used to convert y gm of ice at 0 o C into water at 100 o C. Then the ratio y : x is nearly

Steam at 100 o c is passed into 1.1 g of water contained in a calorimeter of water equivalent 0.02 g at 15 o C till the temperature of the calorimeter and its contents rises to 80 o C. The mass of the steam condensed in g is

The temperature of equal masses of three different liquids A, B and C are 12 o C, 19 o C and 28 o C respectively. The temperature when A and B are mixed is 16 o C and when B and C are mixed is 23 o C. The temperature when A and C are mixed is

A bucket fulI of hot water cools from 75 o C to 70 o C in time T 1 , from 70 o C to 65 o C in time T 2 and from 65 o C to 60 o C in time T 3 , then

The figure given below shows the cooling curve of pure wax material after heating. It cools from A to B and solidifies along BD. lf L and C arc respective values of latent heat and the specific heat of the liquid wax, the ratio L/C is

Two identical conducting rods are first connected independently to two vessels, one containing water at 100 o C and the other containing ice at 0 o C. In the second case, the rods are joined end to end and connected to the same vessels. Let q 1 and q 2 g/s be the rate of melting of ice in two cases, respectively. The ratio of q 1 /q 2 is

A liquid cools down from 70°C to 60°C in 5 minutes. The time taken to cool it from 60°C to 50°C will be

A surveyor’s 30 m steel tape is correct at a temperature of 20°C. The distance between two points, as measured by this tape on a day when the temperature is 35°C, is 26 m. What is the true distance between the points? α steel = 1 .2 × 10 − 5 / ∘ C

A faulty thermometer has its fixed points marked as 5° and 95°. The temperature of a body as measured by the faulty thermometer is 59°. Find the correct temperature of the body on Celsius scale.

The amount of heat required to convert 1 gm of ice at -10° C to steam at 100° C is :

The temperature of equal masses of three different liquids A, B and C are 12 ∘ C , 19 ∘ C and 28 ∘ C respectively, the temperature when A and B are mixed is 16 ∘ C , when B and C are mixed is 23 ∘ C , what is the temperature when A and C are mixed?

Two rods are taken having same length and area and of the same material are joined side by side, heat is allowed to flow through them for 12 minutes. If now the rods are joined in parallel, then how much time will it take to flow the same amount of heat?

The ends of the two rods of conductivities, radii and lengths in the ratio of 1:2 are maintained at the same temperature difference, if the rate of flow of heat through the bigger rod is 4 cals -1 , in shorter it will be (in cals -1 )

A wall has two layers A and B, each made of different material, “A” has thickness 10 cm, while “B” has thickness 20cm, their coefficients of conductivities are in the ratio of 3:1, a constant temperature difference of 35 ∘ c exists across the wall, the difference of temperature across the layer “A” is

The lengths and radii of two rods made of same materials are in the ratio of 1:2 and 2:3 respectively, if the temperature difference between the ends for the two rods be the same, then in steady state, the amount of heat flowing through them will be in the ratio

Volume of mercury in the bulb of a thermometer is 10 -6 m 3 , area of cross section of capillary tube is 2 × 10 -7 m 2 . If the temperature is raised by 100 ∘ C , the length of mercury is ( γ Hg =18 × 10 − 5 ∘ C -1 )

300 grams of water at 25 ∘ C is added to 100 grams of ice at 0 ∘ C , the final temperature of the mixture is

A gas obeys PV 2 =constant in addition to PV=RT. If on heating, the temperature is doubled. The volume of the gas is

Select the correct expression for temperature measured by constant volume gas thermometer.

A graph is drawn between centigrade & Fahrenheit scales such that centigrade on Y-axis and Fahrenheit on X-axis, then slope of the graph

What is the relation between α , β & γ for isotropic solids, where α i s c o e f f i c i e n t o f l i n e a r e x p a n s i o n o f s o l i d , β i s c o e f f i c i e n t o f a r e a l e x p a n s i o n o f s o l i d , γ i s c o e f f i c i e n t o f v o l u m e e x p a n s i o n o f s o l i d

A platinum wire can be sealed through glass, but a brass wire cannot be sealed in glass because

Write the expression for variation in time period of a pendulum clock due to thermal expansion

A scale made of material having coefficient of linear expansion α s at t i C . If temperature is changed to t 2 t 2 > t 1 then error in measurement of scale is

Two rods of different materials will have same different in lengths at all temperatures if they have same expansions then , given ( α 1 , α 2 a r e c o e f f i c i e n t o f l i n e a r e x p a n s i o n s ; l 1 , l 2 a r e l e n g t h s o f r o d s )

If V is the volume of the vessel and V L is volume of liquid to be taken for the free space volume to be constant at all temperatures then

Effect of moment of inertia of a rigid body due to thermal expansion is Δ I I = x α Δ t where x = ( w h e r e I i s m o m e n t o f i n e r t i a ; ∆ I i s c h a n g e i n m o m e n t o f i n e r t i a ; α i s c o e f f i c i e n t o f l i n e a r e x p a n s i o n o f s o l i d ; ∆ t i s c h a n g e i n t e m p e r a t u r e )

If a bimetallic strip is heated then when the strip is vertical

A small amount of mercury ‘Hg’ is taken in a container such that its expansion is equal to expansion of container made of glass then γ H g = x ¯ γ g . Where x = ( γ H g i s c o e f f i c i e n t o f v o l u m e e x p a n s i o n o f m e r c u r y ; γ g c o e f f i c i e n t o f v o l u m e e x p a n s i o n o f g l a s s )

If coefficient of cubical expansion is x times coefficient of superficial expansion, then the value of ‘x’ is

A metal meter scale gives correct measurement at 40 0 C it is generally used at a temperature of 0 0 C . Find the correction to be made for every meter α = 10 − 6 / 0 C

A bimetallic strip of thickness 2cm consists of zinc and silver riveted together. The approximate radius of curvature of the strip when heated through 50 0 C will be ( g i v e n α 1 , α 2 a r e c o e f f i c i e n t s o f l i n e a r e x p a n s i o n o f z i n c = 32 × 10 − 6 / C 0 a n d s i l v e r = 19 × 10 − 6 / C 0 )

A wheel is 80.3 c m in circumference. Its iron tyre measures 80cm around its inner face. If the coefficient of linear expansion for iron is 12 × 10 − 6 / 0 C , the temperature of the tyre must be raised by

The length of each rail is 10m. The linear expansion of steel is 0.000012 / 0 C and the range of variation of temperature at the given place is 15 0 C . So the gap to be provided between the rail is

A continuous flow water heater (geyser) has an electrical power rating of 2kW and efficiency of conversion of electrical power into heat is 80% If water is flowing through device at the constant rate of 100cc/s and the inlet temperature is 10 0 C,the outlet temperature will be (assume density remains constant)

An insulated container, there are two fluid with specific heat capacities c 1 and c 2 , separated by insulating barrier. Liquid temperatures are different. The partition is removed and after the establishment of thermal equilibrium, the difference between initial temperature of first liquid and temperature established in the vessel is two times smaller than the difference between the initial temperatures of liquids. Find the mass ratio of the first and second fluid.

Sun radiates thermal radiation with maximum intensity at the wavelength λ = 0.5 μm while its surface temperature is 6000 K . If sun cools down to a temperature where it emits only 81% of its present power, the maximum intensity will then be emitted at wavelength λ ‘ (in micro metre )is equal to 10 = 3.1622

Figure shows a conductor rod of non uniform cross- section. The ends of the rod are maintained at constant temperatures 100 ∘ C and 0 ∘ C respectively. At steady state, temperatures of P, Q, R and S are T P , T Q , T R and T S respectively, then:

A solid copper cube and a solid copper sphere, both of same mass & emissivity are heated to same initial temperature and kept under identical conditions. What is the ratio of their initial rate of fall of temperature?

A composite slab consists of two slabs A and B of different materials but of the same thickness placed in contact as shown in figure. The thermal conductivity of A and B are k 1 and k 2 respectively. A steady temperature difference of 12 ∘ C is maintained across the composite slab. If k 1 = k 2 2 , the temperature difference across slab A will be:

Two rods of different materials having coefficients of linear expansion α 1 and α 2 and Young’s moduli, Y 1 and Y 2 , respectively, are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If α 1 / α 2 = 2 / 3 , then the thermal stresses developed in the two rods are equal, provided Y 1 /Y 2 is equal to

2 kg of ice at – 20 o C is mixed with 5 kg of water at 20 o C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water remaining in the container. It is given that the specific heats of water and ice are 1 kcal/kg per o C and 0.5 kcal kg/ o C while the latent heat of fusion of ice is 80 kcal/kg.

Three rods of equal length l are joined to form an equilateral triangle PQR. O is the mid point of PQ. Distance OR remains same for small change in temperature. Coefficient of linear expansion for PR and RQ is same i.e. α 2 but that for PQ is α 1 . Then

A student takes 50gm wax (specific heat = 0.6 kcal/kg o C) and heats it till it boils. The graph between temperature and time is as follows. Heat supplied to the wax per minute and boiling point are, respectively

Three rods of identical area of cross-section and made from the same metal form the sides of an isosceles triangle ABC, right angled at B. The points A and B are maintained at temperatures T and 2 T , respectively. In the steady state, the temperature of the point C is T C . Assuming that only heat conduction takes place, T C /T is equal to

Hot water cools from 60 o C to 50 o C in the first 10 minutes and to 42 o C in the next 10 minutes. The temperature of the surrounding is

Three discs A, B and C having radii 2m, 4m, and 6m respectively are coated with carbon black on their other surfaces. The wavelengths corresponding to maximum intensity are 300 run, 400 nm and 500 nm, respectively. The power radiated by them are Q a , Q b , and Q c , respectively,

In an industrial process, 10 kg of water per hour is to be heated from 20°C to 80°C. To do this, steam at 150°C is passed from a boiler into a copper coil immersed in water. The steam condenses in the coil and is returned to the boiler as water at 90°C. How many kg of steam is required per hour? (Take specific heat of steam = 1 calorie per g°C, Latent heat of vaporization = 540 cal/g)

The radiation emitted by a star A is 10000 times that of the sun. If the surface temperatures of the sun and star A are 6000 K and 2000 K, respectively, the ratio of the radii of the star A and the sun is

A metal bar of length L and area of cross-section A is rigidly clamped between two walls. The Young’s modulus of its material is Y and the coefficient of linear expansion is α . The bar is heated so that its temperature increases by θ °C. Then the force exerted at the ends of the bar is given by

At what temperature, if any, do the following pairs of readings give the same reading on Fahrenheit and Kelvin scales?

What will be the temperature, when 150 g of ice at 0°C is mixed with 300 g of water at 50°C? Specific heat of water =1 ca lg-1°C. Latent heat of fusion of ice = 80 -1 ca lg -1 .

80 grams of water at 30° C are poured on a large block of ice at 0° C. The mass of ice melted is:(Latent Heat of fusion of ice =80 cal g – 1 )

A cylinder of radius R made of material of conductivity K 1 is surrounded by a cylindrical shell of internal radius R and outer radius 2R made of material of conductivity K 2 , the two ends of the system are kept at two different temperatures. If there is no loss of heat from the surface, the effective conductivity of the system is

A body in a room cools from 85 ∘ c to 80 ∘ c in 5 minutes. The time taken to cool from 80 ∘ c to 75 ∘ c is

A body cools from 70 ∘ c to 50 ∘ c in 6 minutes. If temperature of surroundings is 30 ∘ c . What is the temperature after 12 minutes?

A slab consists of two layers of two different materials of same thickness having thermal conductivities K 1 and K 2 , the equivalent conductivity of the combination in series is

A cylinder of radius r and thermal conductivity K 1 is surrounded by a cylinder shell of internal radius r and outer radius 3r whose thermal conductivity is K 2 . There is no loss of heat from the surface of the cylinder when the ends of the combined system are maintained at temperatures T 1 and T 2 . The effective thermal conductivity of the system under steady state is

A body coated black at 600Ksurrounded by atmosphere at 300K has cooling rate r 0 the same body at 900K surrounded by the same atmosphere will have cooling rate

Consider a compound slab consisting of two different materials having equal thickness and thermal conductivities K and 2K respectively. The equivalent thermal conductivity of the slabs taken in series is

If a thermometer reads freezing point of water as 20 ∘ c and boiling point is 150 ∘ c how much thermometer read, when the actual temperature is 60 ∘ c

Ice starts forming on the surface of the lake and takes 8 hrs to form a layer of 11 cm thick. How much time will it take to increase the thickness of layer by 2 cm further?

Energy is being emitted from the surface a black body at 127 ∘ C temperature at 1 × 10 6 Js -1 m -2 , temperature of the black body at which the rate of emission is 16 × 10 6 Js -1 m -2 will be

If the temperature of the hot body is increased by 50%. The percentage of amount of radiation emitted is increased by

A clock with a metallic pendulum is 5 seconds fast each day at a temperature of 15 ∘ c and 10 seconds slow each day at a temperature of 30 ∘ c , find the coefficient of linear expansion of the metal?

A uniform pressure P is exerted on all sides of a solid cube at t o c , by what amount should the temperature of the cube be raised in order to bring its volume back to the value it had before the pressure was applied? (K is bulk modulus and α is coefficient of linear expansion?

The coefficient of linear expansion of nickel is 13 × 10 − 6 ∘ C -1 . Find its coefficients of areal and cubical expansion?

Two sphere’s of radii in the ratio 1:2, have specific heats in the ratio 2:3. If their densities are in the ratio 3:4, find the ratio of their thermal capacities.

Three rods of same dimensions have thermal conductivities 3K, 2K and K, they are arranged as shown in the figure, then the temperature of the junction (T) in steady state is

Heat can be measured in SI system

The relation between centigrade scale & Fahrenheit scale is

At what temperature centigrade & Fahrenheit scales are show’s same reading

The average value of ‘ α ‘ for an anisotropic solid is

If a scale is made up of a material at temp t 1 0 C if temperature is changed to t 2 0 C t 2 < t 1 then( coefficient of linear expansion is positive)

If γ g < γ R and γ g is ‘ + V e ‘ then ( h e r e γ g i s c o e f f i c i e n t o f v o l u m e e x p a n s i o n o f g l a s s ; γ R i s c o e f f i c i e n t o f R e a l e x p a n s i o n o f l i q u i d )

A gap should be left between two rails due to

If a graph is drawn between density & temperature, water has maximum density at

Percentage increase in volume Δ V V × 100 = x α Δ t × 100 where x = ( w h e r e α = c o e f f i c i e n t o f l i n e a r e x p a n s i o n o f t h e s o l i d ; ∆ t i s c h a n g e i n t e m p e r a t u r e o f s o l i d )

Radius of circular arc of bent strip of thickness d, when strip temperature is changed to ∆ t is ( w h e r e α 1 , α 2 a r e c o e f f i c i e n t o f l i n e a e x p a n s i o n o f e a c h o f s t r i p )

Due to Anomalous expansion of water

The surface water in a lake is going to freeze. Now the temperature of water at the bottom of lake is nK, where n=

R e l a t i o n a m o n g c o e f f i c i e n t o f v o l u m e e x p a n s i o n o f m a t t e r γ R e a l = γ R , γ a p p a r e n t = γ a & γ g l a s s = γ g i s ( γ R e a l i s r e a l e x p a n s i o n o f l i q u i d , γ a p p a r e n t i s a p p a r e n t e x p a n s i o n o f l i q u i d , γ g l a s s i s v o l u m e e x p a n s i o n o f g l a s s )

Coefficient of volume expansion of a cube is n times coefficient of superficial expansion. Where n is

A faulty thermometer has fixed points marked 5 & 95. What is the correct temperature in centigrade when this thermometer reads 59 0

The pressure of hydrogen gas in a constant volume gas thermometer is 80 c m at 0 0 C , 110 cm at 100 0 C and 95 c m at unknown temperature ‘t’ then ‘t’ is equal to

The resistance of a resistance thermometer has values 2.7 Ω and 3.7 Ω at 0 0 C and 100 0 C respectively. The temperature at which the resistance is 3.1 Ω is

The steam point and the ice point of a mercury thermometer are marked as 80 0 and 20 0 . What will be the temperature in centigrade mercury scale when this thermometer reads 32 0

A metal rod has a length of 1m at 30 0 C , ‘ α ‘ of metal is 2.5 × 10 − 5 / 0 C , the temperature at which it will be shortened by 1mm is

Two iron rods have their lengths in the ratio 5:3 and diameters in the ratio 2:1. When the rods are heated from 30 0 C to 100 0 C the ratio of their expansions is

A crystal has linear coefficient of expansion 9 × 10 − 5 , 12 × 10 − 5 , 7 × 10 − 5 / K along three mutually perpendicular directions the volume expansion coefficient is

Density of a substance at 0 0 C is 10.6 g m / c . c and at 100 0 C is 10 g m / c . c . Coefficient of linear expansion of solid is

A wire of cross sectional area 4 m m 2 is fixed between two points at 30 0 C . Y = 2 × 10 11 P a and α = 10 − 5 / 0 C when the temperature falls to 20 0 C then tension in the string is

A clock with an iron pendulum keeps correct time at 15 0 C . If the coefficient of linear expansion of iron is 0.000012 / 0 C and the room temperature is 20 0 C it loses time in a day in seconds is

Coefficient of apparent expansions of a liquid in gold vessel is ‘G’ & when heated in a silver vessel is ‘S’ if coefficient of linear expansion of Gold is ‘A’, coefficient of linear expansion of silver is

If the coefficient of real expansion γ R is 1% more then coefficient of apparent expansion, linear expansion coefficient of the material is

The sum and difference of coefficient of real & apparent expansions of a liquid are in the ratio 2:1. The ratio of coefficient of real and apparent expansions must be

A fahrenheit thermometer reads 113 0 F while a faulty Celsius thermometer reads 44 0 C one correction to be applied to the Celsius thermometer is

The diameter of a metal ring is ‘ D ‘ and coefficient of linear expansion is α , if the temperature of the ring is increases by 1 0 C , The circumference of the ring will increase by x π D α where x =

Coefficient of cubical expansion of a metal cube is ‘ γ ‘ increase in temperature for which the volume of the cube increases by 5% is x γ where x =

In an experiment to find the coefficient of real expansion of Hg, 70cm coloumn of Hg at 0 0 C is found to balance 71.26c, coloumn of Hg at 100 0 C . γ R of mercury is n × 10 − 6 / 0 C where n=

Two liter glass flask contains some mercury. It is found that at all temperatures the volume of the air inside the flask remains same. The volume of the mercury in side the flask is α f o r g l a s s = 9 × 10 − 6 / 0 C , γ H g = 1.8 × 10 − 4 / 0 C x × 10 − 6 m 3 where x=

A non- isotropic solid metal cube has coefficients of linear expansion as: 5 × 10 − 5 / 0 C along the x-axis and 5 × 10 − 6 / 0 C along the y and the z-axis. If coefficient of volume expansion of the solid C × 10 − 6 / 0 C then the value of C is

M gram of steam at 100°C is mixed with 200 g of ice at its melting point in a thermally insulated container. If it produces liquid water at 40ºC [heat of vaporization of water is 540 cal/g and heat and heat of fusion of ice is 80 cal/ g], the value of M is

When the temperature of a metal wire is increased from 0 0 C to 10 0 C, its length increased by 0.02%. The percentage change in its mass density will be closest to:

A Bakelite beaker has volume capacity of 500 cc at 30ºC. When it is partially filled with V m volume (at 30ºC) of mercury, it is found that the unfilled volume of the beaker remains constant as temperature is varies. If γ b e a ker = 6 × 10 − 6 º C − 1 and γ m e r c u r y = 1 .5 × 10 − 4 º C − 1 , where γ is the coefficient of volume expansion, then V m (in cc) is close to .

A calorimeter of water equivalent 20 g contains 180g of water at 25 0 C. ‘m’ grams of steam at 100 0 C is mixed in it till the temperature of the mixture is 31 0 C. The value of ‘m’ is close to (Latent heat of water = 540 cal g – 1 , specific heat of water = 1 cal g – 1 0 C – 1 )

A metallic sphere cools from 50 0 C to 40 0 C in 300s. If atmospheric temperature around is 20 0 C, then the sphere’s temperature after the next 5 minutes will be close to :

The specific heat of water = 4200 J k g – 1 K – 1 and the latent heat of ice = 3 . 4 × 10 5 J k g − 1 . 100 grams of ice at 0 ° C is placed in 200 g of water at 25 ° C . The amount of ice that will melt as the temperature of water reaches 0 ° C is close to (in grams) :

A bullet of mass 5g , Travelling with a speed of 210 m/s , strikes a fixed wooden target . One half its kinetic energy is converted in to heat in the bullet while the other half is converted in to heat in the wood. The rise of temperature of the bullet if the specific heat of the material is 0.030 cal/ g- 0 C 1 c a l = 4.2 × 10 7 ergs close to:

A block of ice of mass M=13.44 kg slides on a horizontal surface. It starts with a speed v=10.0 m/s and finally stops after moving a distance s = 30 m. What is the mass of ice (in grams) that has melted due to friction between block and surface? Latent heat of fusion of ice is L f =80 cal/g.

Two rods of equal length and diameter have thermal conductivities 3 and 4 units respectively. If they are joined in series, the thermal conductivity of the combination would be:

A Cubical frame is made by connecting 12 identical uniform conducting rods as shown in the figure. In the steady state the temperature of junction A is 100 0 C while that the G is 0 0 C . Then,

The sun having surface temperature T S radiates like a blackbody. The radius of sun is R S and Earth is at a distance R from the centre of sun. Earth absorbs radiation falling on its surface from sun only and is at constant temperature T. If radiation falling on Earth’s surface is almost parallel and Earth also radiates like a blackbody, then

In an Air conditioner compartment of a train if a material of thermal conductivity K and thickness 10 cm is required to fulfill the purpose. To do so there is a need of two glass each of thickness 1 cm with air gap of 8 cm between them. If thermal conductivity of glass and air are 1 W/mK and 0.01 W/mK then the value of K is:

The coefficient of linear expansion of brass and steel are α 1 and α 2 . If we take a brass rod of length l 1 and steel rod of length l 2 at 0 o C, their difference in length l 2 − l 1 will remain the same at all temperatures if

The length of a steel cylinder is kept constant by applying pressure at its two ends. When the temperature of rod is increased by 100 o C from its initial temperature, the increase in pressure to be applied at its ends is Y steel = 2 × 10 11 N / m 2 , α steel = 11 × 10 − 6 / ∘ C , 1 atm = 10 5 N / m 2 .

Apiece of metal weight 46 gm in air, when it is immersed in the liquid of specific gravity 1.24 at 27 o C it weighs 30 gm. When the temperature of liquid is raised to 42 o C the metal piece weight 30.5 gm, specific gravity of the liquid at 42 o C is 1.20, then the linear expansion of the metal will be

The figure shows a glass tube (linear co-efficient of expansion is α ) completely filled with a liquid of volume expansion co-efficient γ . On heating length of the liquid column does not change. Choose the correct relation between γ and α

A lead bullet at 27 o C just melts when stopped by an obstacle. Assuming that 25% of heat is absorbed by the obstacle, then the velocity of the bullet at the time of striking (M.P. of lead = 327 o C, specific heat of lead :0.03 cal/gm o C, latent heat of fusion of lead – 6 cal/gm and J = 4.2J/cal)

In an industrial process 10 kg of water per hour is to be heated from 20 o C to 80 o C. To do this steam at 150 o C is passed from a boiler into a copper coil immersed in water. The steam condenses in the coil and is returned to the boiler as water at 90 o C. How many kg of steam is required per hour? (Specific heat of steam = 1 calorie per gm o C, Latent heat of vaporisation = 540 cal/gm)

A rod of length 20 cm is made of metal. It expands by 0.075cm when its temperature is raised from 0 o C to 100 o C. Another rod of a different metal B having the same length expands by 0.045 cm for the same change in temperature. A third rod of the same length is composed of two parts, one of metal A and the other of metal B. This rod expands by 0.060 cm for the same change in temperature. The portion made of metal A has the length

In an adiabatic process, the pressure of a monoatomic ideal gas increases by 0.5%. The volume will decrease by %

Two litres of water (density = 1 g/ml) in an open lid insulated kettle is heated by an electric heater of power 1 kW. The heat is lost from the lid at the rate of 160 J/s. The time taken for heating water (specific heat capacity 4.2 kJ kg − 1 K − 1 ) from 20°C to 75°C is seconds.

Two rods A and B of different materials are welded together as shown in Fig. If their thermal conductivities are k 1 and k 2 , the thermal conductivity of the composite rod will be

2 kg of ice at -20°C is mixed with 5 kg of water at 20°C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water in the vessel in kg. It is given that the specific heat of water and ice are 1 kcal/kg/°C and 0.5 kcal/kg/°C respectively and the latent heat of fusion of ice is 80 kcal/kg.

The volume of an air bubble becomes three times as it rises from the bottom of a lake to its surface. Assuming atmospheric pressure to be 75 cm of Hg and the density of water to be 1/10 of the density of mercury, the depth of the lake is

An ideal gas has an initial pressure of 3 pressure units and an initial volume of 4 volume units. The table gives the final pressure and volume of the gas (in those same units) in four, processes. Which processes start and end on the same isotherm

If pressure of CO 2 (real gas) in a container is given by P = RT 2 V − b − a 4 b 2 then mass of the gas in container is

The mass, specific heat capacity and the temperature of a solid are 1000 g , 1 2 cal g . C ∘ – 1 and 80 ° C respectively. The mass of the liquid and the calorimeter are 900 g and 200 g . Initially, both are at room temperature 20 ° C . Both calorimeter and the solid are made of same material. In the steady state, temperature of mixture is 40 ° C , then find the specific heat capacity of the unknown liquid.

In electrical calorimeter experiment, voltage across the heater is 100 . 0 V and current is 10 . 0 A . Heater is switched on for t = 700 . 0 s . Room temperature is θ 0 = 10 . 0 ° C and final temperature of calorimeter and unknown liquid is θ f = 73 . 0 ° C . Mass of empty calorimeter is m 1 = 1 . 0 kg and combined mass of calorimeter and unknown liquid is m 2 = 3 . 0 kg . Find the specific heat capacity of the unknown liquid in proper significant figures. Specific heat of calorimeter = 3 . 0 × 10 3 J / kg ° C

How much work can be obtained from 100 calories of heat energy?

The coefficient of expansion of a crystal in one direction (x-axis) is 2.0x 10 -6 K -1 and that in the other two perpendicular (y-and z-axes) direction is 1.6 x 10 -6 K -1 What is the coefficient of cubical expansion of the crystal?

Figure shows a paddle wheel coupled with an agitator submerged in a water tank placed in an ice bath. The thickness of tank walls is 2mm and with thermal conductivity 0 .5 W / m ∘ C . The surface area of tank in contact with water is 0 .05 m 2 . As the block of mass M attached to wheel goes down agitator rotates. It is found that in steady state block goes down at a constant speed of 0.1m/s and water temperature remain constant at 1°C. Find the mass of block (in kg). (Take g = 10 m / s 2 )

If the volume of a block of metal changes by 0.12%. when it is heated through 20°C, then the coefficient of linear expansion is

A body initially at 80°C cools to 64°C in 5 minutes and to 52°C in 10 minutes. The temperature of the body after 15 minutes will be

There are two spherical balls A and B of the same material with same surface, but the diameter of A is half that of B. If A and B are heated to the same temperature and then allowed to cool, then

The melting temperature of a certain mass of a solid object is 20°C. When a heat Q is added to the object, its 3 4 material melts. When an additional amount of Q heat is added the material transforms to its liquid state at 50°C. Find the ratio of specific latent heat of fusion (in J/g) to the specific heat capacity of the liquid (in J g -1 °C -1 ) for the material.

Three rods made of the same material and having the same cross-section have been joined as shown in Fig. Each rod is of the same length. The left and right ends are kept at 0°C and 90°C, respectively. The temperature of the junction of the three rods will be

In an experiment on the specific heat of a metal, a 0.20 kg block of the metal at 150°C is dropped in a copper calorimeter (of water equivalent 0.025 kg) containing 150 cc of water at 27°C. The final temperature is 40°C. If heat losses to the surroundings is not negligible, then the value of specific heat (in cal/g°C) of the metal will be

Calculate the heat of fusion of ice from the following data for ice at 0ºC added to water. Mass of calorimeter = 60 g, mass of calorimeter + water = 460 g, mass of calorimeter + water + ice = 618 g, initial temperature of water = 38°C, temperature of the mixture = 5°C. The specific heat of calorimeter = 0.10 ca lg -1 °C -1 .

The resistance of a platinum-resistance thermometer is found to be 11.00 Ω ,when dipped in a triple point cell. When it is dipped in a bath the resistance is found to be 28.887 W ? Find the temperature of bath in °C on platinum scale.

10 g of water at 70°C is mixed with 5 g of water at 30°C. Find the temperature of the mixture in equilibrium.