28/03/2020 Thermal Properties and Processes – Expansivity, Heat Transfer(Senior Class Physics Study by Topics) 0Comments by Gate Academy Welcome to your Thermal Properties and Processes - Expansivity, Heat Transfer(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. Mercury has the boiling point of357 °C257 °C157 °C57 °C2. 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 = 7:5.79.166°C20.157°C80.548°C58.147°C3. When the first law of thermodynamics, Q = ΔU + W, is applied to an ideal gas that is taken through an isothermal process,ΔU = 0None of the aboveW = 0Q = 04. The energy due to which the molecules held at a fixed position vibrate, this energy is termed asphysical energychemical energyexternal energyinternal energy5. Which term is used to define the temperature at which a substance changes its status from solid to liquid?Boiling pointCondensation pointMelting pointFreezing point6. Which of the following is an effective coolant?AcidsWaterOilMecury7. Temperature is a microscopic concept.FalseTrue8. 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 HgFrom 13.5°C to 14.5°C at 76mm of HgFrom 98.5°C to 99.5°C at 760mm of HgFrom 14.5°C to 15.5°C at 760mm of Hg9. The specific heat capacity of a pure substance Is a fixed valueIs always changing as the temperature increasesDepends on its structureDoes not depend on the purity of the substance10. An ideal black body is thrown into a furnace. The black body is room temperature. It is observed that _______It cannot be distinguished at all timesInitially, it is the darkest body and at later it cannot be distinguishedAt all times it is the darkest bodyInitially, it is darkest body and at later times the brightest11. A green glass heated in a furnace when taken out in dark glows red.TrueFalse12. On a hilly region, water boils at 95°C. What is the temperature expressed in Fahrenheit?150°F203°F20.3°F100°F13. What happens when you heat china having some dark paintings engraved on it at 1000°C and then examine it in a dark room immediately?The china dish will develop patternsThe dark painting will appear much brighterThe whole china dish will be brightThe china dish doesn’t glow14. Why locations next to large water bodies tend to have a moderate climate than those further inland?Because of the latitudeBecause of specific heat of waterBecause of the heating effects of sunBecause of the water in clouds15. The heat capacity of a material defined as ___________C = m . dE/dTC = dT/dQC = dQ/dTC = 1/m . dE/dT16. 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? -96 J-36 J36 J96 J17. In an experiment, 100 g of liquid requires 12600 J of thermal energy to raise it from 30 °C to 60 °C, the thermal capacity of 100 g of water is420 J K-1420 J K300 J K300 J K-118. When the state is being changes from gas to liquid through the process of condensation, the temperaturedecreasesmay increase or decreaseremains constantincreases19. The internal energy comprises of two types of energies, those arekinetic and potential energymagnetic and electrical energymechanical and electrical energykinetic and magnetic energy20. 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?Spherical bulbNone of the mentionedElongated cylindrical bulbAll of the mentioned21. A composite rod made of copper (1.8×10(-5) K(-1)) and steel (α=1.2×10(-5) K(-1)) is heated. Then _____It bends with copper on concave sideIt does not expandData is insufficientIt bends with steel on concave side22. A block of copper weighs 3.0 kg. Copper has a specific heat capacity of 390 J kg-1K-1. It is cooled in the freezer so that the temperature drops from 25.0oC to 0.0oC. What is the total energy lost by the block of copper?29250 J32950 J23400 J22950 J23. 540g of ice at 0°C is mixed with 540g of water at 80°C. What is the final temperature of the mixture?0°CLess than 0°80°C40°C24. 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 toboiling of the perfumemelting of the liquidevaporation of the liquidcondensing of the duedorent25. Specific heat of materials is expressed in terms of __________J/Km³/kgJ/kg KW/m K26 out of 25Time is Up!