Page 1 :
Dr.rafiq Zakaria Campus, MAULANA AZAD COLLEGE, OF ARTS, SCIENCE, AND, , COMMERCE, PG AND RESEARCH CENTRE, Text- Unit Operation in chemical industry (IC-102) Date: 04-05-2021, Time: 11:30 pm To 12:30 par Max Marks-20, , 1) Unit of the rate of heat transfer is, a) Joule, , b) Newton, , c) Pascal, , d) Watt, , 2) Convective heat transfer coefficient doesn't depend on, a) Surface area, , b) Space, , c) Time, , d) Orientation of solid surface, , 3) Heat transfer takes place according to which law?, a) Newton's law of cooling, , b) Second law of thermodynamics, , ¢) Newton's second law of motion, , d) First law of thermodynamics, , 4) Identify the wrong statement, , a) The process of heat transfer is an irreversible process, , b) For heat exchange, a temperature gradient must exist, , ¢) A material medium is not necessary for heat transmission, d) Heat flow doesn’t depend on temperature, , 5) Transmission of heat ie molecular is smallest in case of, a) Gases, , b) Liquids, , c) Alloys, , d) Solids
Page 2 :
6) Which one of the following forms of water have the highest value of, thermal conductivity?, , a) Boiling water, , b) Steam, , ¢) Solid ice, , d) Melting ice, , 7) Typical examples of heat conduction through cylindrical tubes are not, found in, , a) Power plants, , b) Oil refineries, , ) Most process industries, , d) Aircrafts, , 8) The rate of heat conduction through a cylindrical tube is usually expressed, , as, a) Per unit length, b) Per unit area, ¢) Only length, d) Only area, , 9) For steady state and a constant value of thermal conductivity, the, temperature distribution associated with radial convection through a cylinder, is, , a) linear, , b) parabolic, , ¢) Logarithmic, , d) Exponential, , 10) If we increase the thickness of insulation of a circular rod, heat loss to, surrounding due to, , a) Convection and conduction increases, , b) Convection and conduction decreases, , ©) Convection decreases while that due to conduction increases, , d) Convection increases while that due to conduction decreases, , 11) For the same amount of fabrication material and same inside capacity, the, heat loss is lowest in, , a) Sphere, , b) Cylinder
Page 3 :
c) Rectangle, d) Cube, , 12) The value of critical radius in case of a cylindrical hollow object is, a) 2k/h, , b) 2h/k, , c) k/h, , d) h/k, , 13) For insulation to be properly effective in restricting heat transmission, the, pipe radius ro will be, , a) Greater than critical radius, , b) Less than critical radius, , c) Equal to critical radius, , d) Greater than or equal to critical radius, , 14) Which one of the following materials are quickly heated by applying high, frequency?, , a) Textiles, , b) Engines, , c) Rubber, , d) Coal, , 15) Generally, heat generated depends on some parameters. It is directly, proportional to, , a) Time, , b) Conductivity, , c) Voltage, , d) Distance between plates, , 16) A cavity with a small hole will always behave as a, a) White body, , b) Transparent body, , ¢) Black body, , d) Opaque body, , 17) The main property that affects a boundary layer ts___, a) Temperature, , b) Pressure, , c) Viscosity
Page 4 :
d) Surface tension, , 18) The layer that is influenced by a planetary boundary is called__, a) Atmospheric boundary layer, , b) Lithosphere, , c) Troposphere, , d) Hydrosphere, , 19) The drag coefficient is directly proportional to the ___, a) Drag force, , b) Mass density, , c) Area, , d) Flow speed, , 20) There will be a transition from laminar flow to turbulent flow when__, a) Reynolds number increases, , b) Reynolds number decreases, , c) Reynolds number is the same, , d) Froude’s number increases, , poemeacennanncennnmneenn sola Wid mernmareinemnemanenen
