TMA4/PHY101

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My TMA Home TMA Results My Pending TMA Quick Help TMA Quiz Questions TMA: TMA4/PHY101 Matric Number:  SCORE=8.00 PHY101 - Elementary Mechanics, Heat and Properties of Matter Mr. Ibanga Efiong (eibanga@noun.edu.ng ) 1 An ideal gas is in equilibrium at initial state with temperature T=137oC$$T={137}^{o}C$$ , pressure P = 0.75Pa and volume V=0:75m3$$V=0.75m^3$$ . If there is a change in state in which the gas undergoes an isothermal process to a final state of equilibrium during which the volume is doubled. Calculate the temperature and pressure of the gas at this final state. 187oC$${\mathrm{}}^{}$$ and 0.19m3$$\mathrm{}{}^{\mathrm{}}$$ 394oC$${\mathrm{}}^{}$$ and 0.38m3$$\mathrm{}{}^{\mathrm{}}$$ 187oC$${\mathrm{}}^{}$$ and 0.38m3$$\mathrm{}{}^{\mathrm{}}$$ 394oC$${\mathrm{}}^{}$$ and 0.19m3$$\mathrm{}{}^{\mathrm{}}$$ 2 Which of the following correctly represents the temperature of an ideal gas? 3Rn2Ek$$\frac{\mathrm{}}{\mathrm{}{}_{}}$$ 2Ek3Rn$$\frac{\mathrm{}{}_{}}{\mathrm{}}$$ Ek3R$$\frac{{}_{}}{\mathrm{}}$$ 2EkRn$$\frac{\mathrm{}{}_{}}{}$$ 3 A scientist uses a scale Y for measuring temperature. In this scale, pure water melts at 10oY$${\mathrm{}}^{}$$ and boils at 130oY$${\mathrm{}}^{}$$ at standard atmospheric pressure. The scientist measures the temperature at which sodium melts to be 127oY$${\mathrm{}}^{}$$ . Express this temperature in degrees Celsius 97.5oC$${\mathrm{}}^{}$$ 102.6oC$${\mathrm{}}^{}$$ 38.6oC$${\mathrm{}}^{}$$ 196.6oC$${\mathrm{}}^{}$$ 4 When the junctions of two dissimilar metals are maintained at different temperatures an electromotive force is is set up in the circuit of which these junctions are part. A pair of juntions of this kind and the effect are known respectively as thermistor and Peltier effect resistance thermometer and Joule effect pyrometer and Joule effect thermocouple and Seebeck effect 5 The temperature at which the tungsten filament of a 12V and 36W lamp operates is 1730oC$${\mathrm{}}^{}$$ . If the temperature coefficient of resistance of tungsten is 6×10−3/K$$\mathrm{}{\mathrm{}}^{\mathrm{}}$$ , find the resistance of the lamp at a room temperature of 20oC$${\mathrm{}}^{}$$ 10.00Ω$$\mathrm{}\mathrm{}$$ 0.45Ω$$\mathrm{}\mathrm{}$$ 0.39Ω$$\mathrm{}\mathrm{}$$ 4.00Ω$$\mathrm{}\mathrm{}$$ 6 A certain resistance thermometer at triple point of water has resistance of 152.0Ω$$\mathrm{}\mathrm{}$$ . What is the temperature of the system in degrees Celsius when the resistance of the thermometer is 230.51Ω$$\mathrm{}\mathrm{}$$ ? 414.2oC$${\mathrm{}}^{}$$ 141.0oC$${\mathrm{}}^{}$$ 253.2oC$${\mathrm{}}^{}$$ 80.4oC$${\mathrm{}}^{}$$ 7 Which of these determines whether or not heat flows in a system? average speed of the consituent particles of the system pressure difference between parts of the system degree of hotness or coolness of the system temperature difference between parts of the system 8 Which of the following is NOT true about conduction as a means of heat transfer? transfer of heat occurs through sucessive collisions of the atoms or molecules the average kinetic energy of the atoms or molecules is greater in the hot object than in the cold object the transfer process requires a material medium for it to take place there is net translational motion of the atoms or molecules from their mean equilibrium positions 9 The first law of thermodynamics may be written in he form ΔU=ΔQ+ΔW$$\mathrm{}\mathrm{}\mathrm{}$$ , where the symbols have their usual meaning. Which of the following is correct for the case of an isothermal expansion of an ideal gas? ΔW>0$$\mathrm{}\mathrm{}$$ ΔW=0$$\mathrm{}\mathrm{}$$ ΔU=0$$\mathrm{}\mathrm{}$$ ΔU>0$$\mathrm{}\mathrm{}$$ 10 Which statement about internal energy is correct The internal energy of a system can be be increased without transfer of energy by heating The internal energy depends only on its temperature When the internal energy of a system is increased, its temperature always rises When two system have the same internal energy, they must be at the same temperature 11 Calculate the electric power which must be supplied to the filament of of a light bulb operating at 3000K. The total surface area of the filament is 8×10−6m2$$\mathrm{}{\mathrm{}}^{\mathrm{}}{}^{\mathrm{}}$$ and its emissivity is 0.92. 20.3W 33.8W 46.4W 56.7W 12 Calculate the change in internal energy of 2kg of water at 90oC$${\mathrm{}}^{}$$ when it is changed to 3.30m3$$\mathrm{}{}^{\mathrm{}}$$ of steam at 100oC$${\mathrm{}}^{}$$ . The whole process occurs at atmospheric pressure. The latent heat of vaporization of water is 2.26×106J/kg$$\mathrm{}{\mathrm{}}^{\mathrm{}}$$ . 4.27 MJ 3.43 kJ 45.72 mJ 543.63 J 13 A 0.5kg piece of metal (c = 600/kgK) at 300 degree celcius is dumped into a large pool of water at 20 degrees celcius. Assuming the change in temperature of water to be negligible, calculate the overall change in entropy for the system 85.5J/K 67.4J/K 122.3J/K 202.3J/K 14 Calculate how much heat is needed to be supplied to a gas at a pressure of 1.25×105Pa$$\mathrm{}{\mathrm{}}^{\mathrm{}}$$ , such that the pressure increases by 25 per cent at constant volume, and the internal energy by 120J. 240J 120J 320J 480J 15 The average kinetic energy of the molecules of an ideal gas in a close, rigid container is increased by a factor of 4. What happens to the pressure of the gas? It remains constant It increases by a factor 2 It increases by a factor of 4 It increases by a factor of 8 16 At what temperature will the root-mean-square speed of oxygen molecules have the value of 640 m/s? 1 kilomole of oxygen has a mass of 32kg. 252.5oC$${\mathrm{}}^{}$$ 332.3oC$${\mathrm{}}^{}$$ 272.2oC$${\mathrm{}}^{}$$ 373.2oC$${\mathrm{}}^{}$$ 17 It is NOT possible to completely convert heat into internal energy mechanical energy into heat internal energy into mechanical energy internal energy into heat 18 The second law of thermodynamics is a statement of the law of conservation of energy say that heat cannot be completely converted into mechanical energy is the basis for the definition of temperature is the basis for the definition of internal energy 19 The predominant mode of heat transfer in solids is ----------- convection conduction radiation diffusion 20 A piece of plastic barely floats in water. If it has a mass of 20g, what is its volume? 30cm3$$\mathrm{}{}^{\mathrm{}}$$ 20cm3$$\mathrm{}{}^{\mathrm{}}$$ 10cm3$$\mathrm{}{}^{\mathrm{}}$$ 2cm3$$\mathrm{}{}^{\mathrm{}}$$