540 g of ice at 0o C is mixed with 540 g of water at 80o C. The final temperature of the mixture is
Three disc A, B and C having radii 2 m, 4 m and 6 m respectively are coated with carbon black on their outer surfaces. The wavelengths corresponding to maximum intensity are 300 nm, 400 nm and 500 nm respectively. The powers radiated by them are QA, QB and QC respectively will be :
QA is maximum
QB is maximum
QC is maximum
QA = QB = QC
The graph shown in the adjacent diagram, represents the variation of temperature (T) of two bodies X and Y having the same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity and absorptivity power of the two bodies ?
eX < eY and aX > aY
eX > eY and aX > aY
eX < eY and aX < aY
A sphere is at a temperature of 600K. Its cooling rate is R' in an external environment of 200 K. If temperature falls to 400 K, then cooling rate R' will be
none of these
Assuming the sun to be a spherical body of radius R at a temperature of TK. Evaluate the total radiant power incident on earth at a distance r from the sun ?
A body cools from 60°C to 50°C in 10min. If room temperature is 25°C , the temperature of the body at the end of next 10 min will be
An ungraduated thermometer of uniform bore is attached to a centimetre scale and is found to read 10.3 cm in melting ice, 26.8 cm in boiling water and 6.5 cm. in freezing mixture. The temperature of the freezing mixture will be :
The temperature coefficient of resistance of a wire is 0.00125oC-1. At 300 K, its resistance is 1 Ω. The resistance of the wire will be 2 Ω at which temperature ?
In which of the following processes, convection does not take place primarily ?
Sea and land breeze
Boiling of water
Warming of glass of the bulb due to filament
Heating air around a furnace
The radiator of a car contains 20 litre of water. If the motor supplies calorie heat to it, then rise in temperature will be :