Welcome to your Thermal Properties and Processes - Expansivity, Heat Transfer(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. The specific heat capacity of a pure substance Does not depend on the purity of the substance Depends on its structure Is always changing as the temperature increases Is a fixed value None 2. Why is the roof of buildings painted white Because it reflects radiations Because it absorbs radiation Because it conducts heat Because it is cheaper None 3. When potassium is added to water, it is seen that the lower region becomes warm first and becomes less dense. It then moves up and the more dense cold water comes down and the process goes on. What is the process taking place? Radiation Conduction Purification Convection None 4. Specific heat of materials is expressed in terms of __________ m³/kg J/kg K J/K W/m K None 5. Temperatures of two stars are in ratio 3:2. If wavelength of maximum intensity of first body is 4000 Å, what is corresponding wavelength of second body? 9000 Å 2000 Å 8000 Å 6000 Å None 6. An ideal black body is thrown into a furnace. The black body is room temperature. It is observed that _______ At all times it is the darkest body Initially, it is the darkest body and at later it cannot be distinguished It cannot be distinguished at all times Initially, it is darkest body and at later times the brightest None 7. When the state is being changes from gas to liquid through the process of condensation, the temperature may increase or decrease increases decreases remains constant None 8. What effect does the addition of thermal energy have on a material? Thermal contraction Thermal expansion Reproduction No change None 9. When you hang your t-shirt or jeans on a rope to dry it out, it dries fast even if there is no sun, this is due to condensing of the duedorent evaporation of the liquid melting of the liquid boiling of the perfume None 10. Compared to burn due to air at 100°C, a burn due to steam at 100°C is _______ Equally dangerous More dangerous Less dangerous Not dangerous None 11. Solids with weekly bonded electrons are good conductors of heat. False True None 12. What effect do thermal variations in volume have on a body? Phase transformation Contraction Expansion Cracking None 13. Calorie is defined as the amount of heat required to raise the temperature of 1g of water by 1°C and it is defined under which of the following conditions? From 3.5°C to 4.5°C at 76mm of Hg From 14.5°C to 15.5°C at 760mm of Hg From 13.5°C to 14.5°C at 76mm of Hg From 98.5°C to 99.5°C at 760mm of Hg None 14. Which term is used to define the temperature at which a substance changes its status from solid to liquid? Boiling point Condensation point Melting point Freezing point None 15. Two thermometers are constructed in the same way except that one has a spherical bulb and the other an elongated cylindrical bulb. Which of the two will respond quickly to temperature changes? None of the mentioned All of the mentioned Spherical bulb Elongated cylindrical bulb None 16. A milkman boils the milk before distributing it in the pots. He raises the temperature of the milk from 10 °C to 130 °C with the thermal energy of 120000 J. If the mass of the milk is 25 kg, the specific heat capacity of the milk would be 120 J kg -1 °C-1 80 J kg -1 °C-1 160 J kg -1 °C-1 40 J kg -1 °C-1 None 17. How is the spalling resistance index defined? k/cpP αlΔT P/A hS/αE None 18. A pure substance would freeze or solidify at its melting point boiling point sublimation point condensation point None 19. When one end of the rod is heated, the molecules at the hot end vibrate with higher amplitude and transmit the heat from one particle to the adjacent particle and so on. What is the process? Transmittance Convection Radiation Conduction None 20. If the sun were to increase in temperature from T to 2T and its radius from R to 2R, then the ratio of the radiant energy received on earth to what it was previously, will be _______ 64 4 32 16 None 21. A system consists of 3.0 kg of water at 80°C. 30 J of work is done on the system by stirring with a paddle wheel, while 66 J of heat is removed. What is the change in internal energy of the system? 36 J 96 J -96 J -36 J None 22. The internal energy comprises of two types of energies, those are kinetic and potential energy kinetic and magnetic energy mechanical and electrical energy magnetic and electrical energy None 23. The melting point of Iron (Fe) is _________ 660°C 419°C 1538°C 1084°C None 24. The outer ends of two bars A and B are at 100°C and 50° respectively. Calculate the temperature at the welded joint if they have the same cross-section and the same length and their thermal conductivities are in the ratio of A:B = 7:5. 80.548°C 79.166°C 20.157°C 58.147°C None 25. The temperature of a body can be negative on the Kelvin scale. True False None 1 out of 25 Time's upTime is Up!