The average K.E. of the thermal neutrons are similar to that of molecules of a real gas. Find the wavelength of thermal neutrons at 27°C ( mass of neutron = 1.0086 amu, k = ` 1.38 xx 10 ^(-23)` J /K.

Two bodies having masses 1g and 4g are moving with equal K.E find the ratio of their linear momentum.

For what kinetic energy of a neutron will the associated de - Broglie wavelength be 1.4 xx 10^(-10) m?

A hole is drilled in a copper sheet. The diameter of the hole is 4.24 cm at 27.0 ^@C . What is the change in the diameter of the hole when the sheet is heated to 227 ^@C ? Coefficient of linear expansion of copper = 1.70 xx 10^-5 K^-1 .

A large steel wheel is to be fitted on to a shaft of the same material. At 27 ^@C , the outer diameter of the shaft is 8.70 cm and the diameter of the central hole in the wheel is 8.69 cm. The shaft is cooled using ‘dry ice’. At what temperature of the shaft does the wheel slip on the shaft? Assume coefficient of linear expansion of the steel to be constant over the required temperature range: a_ steel = 1.20 xx 10^-5K^-1 .

Calculate the root mean square speed of gas particles each of mass 5xx10^(-17) kg at NTP(K_B = 1.38xx10^(-23) JK^(-1)]

A brass rod of length 50 cm and diameter 3.0 mm is joined to a steel rod of the same length and diameter. What is the change in length of the combined rod at 250 ^@C , if the original lengths are at 40.0 ^@C ? Is there a ‘thermal stress’ developed at the junction? The ends of the rod are free to expand (Co-efficient of linear expansion of brass = 2.0 xx 10^-5K^-1 steel = 1.2 xx 10^-5 K^-1) .

A steel tape 1m long is correctly calibrated for a temperature of 27.0 ^@C . The length of a steel rod measured by this tape is found to be 63.0 cm on a hot day when the temperature is 45.0 ^@C . What is the actual length of the steel rod on that day? What Is the length of the same steel rod on a day when the temperature is 27.0 ^@C ? Coefficient of linear expansion of steel = 1.20xx10^-5 K^-1 .

A brass boiler has a base area of 0.15 m2 and thickness 1.0 cm. It boils water at the rate of 6.0 kg/min when placed on a gas stove. Estimate the temperature of the part of the flame in contact with the boiler. Thermal conductivity of brass = 109 J s ^-1m^- 1K^-1 , Heat of vaporisation of water = 2256 xx 10^3 J kg^-1 .