SAMPLE QUESTIONS
- A composite wall is 6m long and 3.2 m high. It is made of outer metallic layer of 2.1 cm. Then a layer of Freon 8 cm thick and plywood being 4.5 cm thick is provided. The total temperature drop across the wall is 200C. Calculate the temperature drop across the metallic plate ( in C). λmetal = 64 W/mK, λFreon = 0.07 W/mK, λplywood = 0.13 W/mK
- An iron ball 240.5 kg is lifted by a pulley from ht 11.8m in 21 seconds efficiency=75%. g=9.81 calculate energy in kWhr.
- 2.5 kg of brass of specific heat 0.39 kJ/kg K at a temperature of 176 C is dropped into 1.2 litre of water at 14 C. Find the resultant temperature of the mixture. Specific heat of water is 4.2 kJ/kg K
- The rotating speed of shaft is 42 rev/s. the shaft rotates between fluid cooled bearing diameter 14 cm and force between surface of the shaft and bearing is 82 kN. Coefficient of friction is 0.63. Calculate sp. heat in KJ/kg K.
- Work done is 1868.40 J, for moving a box using a force of 540 N; find the distance by which the box is moved.
- An aluminum bar 0.6 kg, is held in flue gases such that it attains the temp. of the gases than it is dropped into an insulated calorimeter containing 3.6 kg of water at 16 C. Reset temperature is 18 c. Calculate the temp of flue gases ;specific heat of aluminum is 0.91 kJ/kg K. Specific heat of water is 4.2 kJ/kg K
- A wall is 3.2 m long, 2.1 m high and the outer surface of the wall is 21 cm thick ,the temperature difference is 16 deg. C and k=0.82 Wm/K. calculate the heat transfer per min.
- Convert 84 F to deg. C
- Otto cycle bore diameter 150MM and stroke 375mm; P1=1 bar, P2= 25 bar T1= 50⁰c,efficiency= 67.013% Calculate the clearance volume.
- C.O.P=2.10 ,it absorbs 63 KJ of the from a cold reservoir pressure in each cycle, calculate the mechanical energy required.
- The initial pressure of a gas is 64 kN/m^2 and volume is 2.8 m^3,if the pressure is decreased by 45%,than find the% increase in volume at constant temp.
- If RADIUS OF THE WIRE IS R=20mmH OF THE WIRE ,LENGTL=450mm AT INTIAL TEMP. T1=30⁰c & FINAL TEMP. T2=200⁰c steel=16.6 X 10-6 E=117 GN/m2 ;Find stress ?
- A fluid is flowing at a speed of 4.9 m/s through a cylindrical pipe volume flow is 0.132m/s^3.find the radius of pipe.
- Convert 7.32 deg. C to absolute temp
- A freezer has a co-efficient of performance of 2.40;the freezer is used to convert 3 Kg of water at 25⁰c to 3Kg of ice -10⁰c in one hour.
- How much electrical energy is consumed by the freezer during this hour? Your answer should rounded off. Assume that sp. heat of water 4.190 KJ/Kg K; Latent heat of fusion= 334 KJ/Kg K; sp. Heat of ice= 2.01 KJ/Kg K
- Bore = 250 mm; stroke =375mm CV=0.00263M3, P1=1bar, Pmax= 25 bar T1=50C, find Efficiency of Otto CYCLE
- Convert 85.6 F to deg. C
- Pressure in an engine cylinder is 9x10^5 and temp. 400 k; if the max pr. that the cylinder can withstand is2.5x10^6, than find the temp. at which the cylinder will crack.
- The compression ratio of an engine working on diesel cycle is 7. At the beginning of compression, the temperature is 230 C and at the end of combustion, the temperature is 900 C. take the value of γ as 1.4, calculate the efficiency.
- An engine works between the temperature limits of 1775 K and 375 K. What can be the maximum thermal efficiency of this engine?
- Suppose a freeze has a cop 2.40, the freeze is to convert 2 kg of water at 30 c to 2 kg of ice at -10° c in 1 hr how much wasted heat is rejected to the room in which the freeze sits Cw=4.190,LF=334 Ci = 2.01.
- Water equivalent of a metallic hammer of mass 1.8 kg is 0.48 kg. Calculate the specific heat of the metal ( in kJ/kg). The specific heat of water is 4.2 kJ/kg K
- A gas occupies a volume of 0.1 m3 at a temperature of 200 C and a pressure of 1.5 bar. Find the final temperature (in 0C) of the gas, if it is compressed to a pressure of 7.5 bar and occupies a volume of 0.04 m3.
- In an Otto cycle, the temperatues at the beginning and end of the isentropic compression are 316 K and 596 K respectively. Determine the air standard efficiency. Take Υ = 1.4