At what temperature, if any, do the following pairs of scales gives the same reading?
Fahrenheit and Kelvin.

A box having total surface area 0.05 m² and of 6 mm thick side walls is filled with melting ice and kept in room. Calculate the thermal conductivity of the box material if 0.5 kg of ice melts in 1 h. The room temperature is 40^o C and latent heat of fusion of ice = \(3.33\times { 10 }^{ 5 }J{ kg }^{ -1 }\)

Explain the following
(i) Hot tea cools rapidly when poured into the saucer from the cup.
(ii) Temperature of a hot liquid falls rapidly in the beginning but slowly afterward.
(iii) A hot liquid cools faster if outer surface of the container is blackened.

A fat man is used to consuming about 3000 kcal worth of food every day. His food contains 50g of butter plus a plate of sweets every day, besides items which provide him with other nutrients (proteins, vitamins, minerals, etc) in addition to fats and carbohydrates. The calorific value of 10g of butter is 60kcal and that of a plate of sweets is of average 700kcal per day? Assume the man cannot resist eating the full plate of sweets once it is offered to him.

A metallic ball has a radius of 9.0 cm at 0⁰C. Calculate the change in its volume when it is heated to 90⁰ C. Given the coefficient of linear expansion of metal of ball is 1.2 x 10^-5 K.

Two bodies A and B have thermal emisivities of 0.01 and 0.81 respectively. 771eouter surface area as of both the bodies are same. The two emit the same total radiated power. The wavelength \(\lambda \)_B corresponding to the maximum intensity in radiations from B, is shifted from the wavelength \(\lambda \)_A corresponding to the maximum intensity in radiations from A by 1um. If the tempera tu re of hody A is 5802 K find the temperature of body B and the wavelength \(\lambda \)_B

Two vessels made of two different metals are ideu tical in all respects. They are completely filled with ice at O°c. The ice in one is melted in 30 minutes and that in another in 10 minutes by heat coming jroin au tside. Compare the thermal conductivities of metals.

Is the rate of cooling the same thing as the rate of loss of heat? Explain

why does a gas not have a unique value of specific heat ?

On what factors the amount oj treat flowing from hot face to the cold face depends ? How ?

A metallic wire has resistance of 20 ohm at 20°C and a resistance of 21.2 ohm at 40°C. Calculate the temperature coefficient of resistance

When 0.2 kg of a body at 100°C is dropped into 0..5 kg of water at 10°C, the resulting temperature is 16°C. Find the specific heat of the body. Specific heat of water is 4.2 x 10³ J/kg/⁰c.

A liquid cools from 70°C to 60°C in 5 minutes. Calculate the time taken by the liquid to coolfrom 60°C to 50°C, if the temperature of the surrounding is constant at 30°C.

A lead bullet strikes against a steel armour plate with the velocity of 300 ms^-1. If the bu llet falls dead after the impact, find the rise in temperature of the bullet, assuming that the heat produced is shared equally between the bullet and the target. Specific heat of lead = 0.03 cal g^-10C^-1