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. 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 J36 J96 J-96 J2. A faulty thermometer has its fixed points marked as 5° and 95°. The temperature of a body as measured by the faulty thermometer is 59°. Find the correct temperature of the body on a Celsius scale.20°C0°C40°C60°C3. Why locations next to large water bodies tend to have a moderate climate than those further inland?Because of the water in cloudsBecause of specific heat of waterBecause of the heating effects of sunBecause of the latitude4. 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 be80 J kg -1 °C-140 J kg -1 °C-1120 J kg -1 °C-1160 J kg -1 °C-15. The temperature at which plastics begin to become softer and defer under a load is known as _________Softening pointEutectic pointMelting pointHeat distortion point6. 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 sideData is insufficientIt bends with steel on concave sideIt does not expand7. A pure substance would freeze or solidify at itsmelting pointcondensation pointboiling pointsublimation point8. The internal energy comprises of two types of energies, those aremagnetic and electrical energymechanical and electrical energykinetic and magnetic energykinetic and potential energy9. 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?2000 Å9000 Å8000 Å6000 Å10. When the first law of thermodynamics, Q = ΔU + W, is applied to an ideal gas that is taken through an isothermal process,None of the aboveQ = 0ΔU = 0W = 011. The thermometer bulb should have ______No heat capacitySmall heat capacityHigh heat capacityVarying heat capacity12. Temperature is a microscopic concept.FalseTrue13. Mercury has the boiling point of357 °C157 °C257 °C57 °C14. The amount of energy required to change the liquid to gas and vice versa without any change in temperature is termed asLatent Heat of VaporizationHeat CapacityLatent Heat of FusionSpecific Heat Capacity15. 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°C79.166°C58.147°C20.157°C16. 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 14.5°C to 15.5°C at 760mm of HgFrom 3.5°C to 4.5°C at 76mm of HgFrom 98.5°C to 99.5°C at 760mm of HgFrom 13.5°C to 14.5°C at 76mm of Hg17. What happens when a material is heated?It burstsIt expandsIt meltsIt contracts18. What effect do thermal variations in volume have on a body?ContractionCrackingPhase transformationExpansion19. Specific heat of materials is expressed in terms of __________m³/kgJ/kg KW/m KJ/K20. 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 dark painting will appear much brighterThe whole china dish will be brightThe china dish will develop patternsThe china dish doesn’t glow21. 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 perfumeevaporation of the liquidcondensing of the duedorentmelting of the liquid22. The temperature of a body can be negative on the Kelvin scale.FalseTrue23. The energy due to which the molecules held at a fixed position vibrate, this energy is termed asexternal energyinternal energychemical energyphysical energy24. 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?RadiationTransmittanceConductionConvection25. 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 mentionedAll of the mentionedElongated cylindrical bulb26 out of 25Time is Up!