The main factor on which the behaviour of a mass of fluidised solid depends mainly is the___________________?

Related Mcqs:

1. The uniformity of a gas fluidised bed depends upon the _______________ of the solid particles?

   A. Size
   B. Surface properties
   C. Both A. and B.
   D. Neither A. nor B.

2. When a fluid flows over a solid surface, the___________________?

   A. Velocity is uniform at any cross-section
   B. Velocity gradient is zero at the solid surface
   C. Resistance between the surface & the fluid is lesser as compared to that between the fluid
   layers themselves
   D. Velocity is not zero at the solid surface

3. Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the___________________?

   A. Pipe length
   B. Fluid velocity in the pipe
   C. Time taken to close the valve
   D. All A., B. and C.

4. Minimum fluidisation velocity for a specific system depends upon the___________________?

   A. Particle size
   B. Fluid viscosity
   C. Density of both the particle & the fluid
   D. All A., B. and C.

5. Pressure drop in a fluidised bed reactor is ______________ that in a similar packed bed reactor?

   A. Less than
   B. Greater than
   C. Same as
   D. None of these

6. Slugging occurs in a fluidised bed, if the bed is___________________?

   A. Narrow
   B. Deep
   C. Both A. & B.
   D. Neither A. nor B.

7. With decrease in particle size to be fluidised by a particular fluid, the operating range of fluidisation velocity___________________?

   A. Widens
   B. Squeezes
   C. Does not change
   D. Unpredictable from the data

8. A 0.5 m high bed made up of a 1 mm dia glass sphere (density 2500 kg/m3 ) is to be fluidised by water (density 1000 kg/m3 ). If at the point of incipient fluidisation, the bed voidage is 40%, the pressure drop across the bed is________________?

   A. 4.4 KPa
   B. 2.94 KPa
   C. 3.7 KPa
   D. None of these

9. Fluidised beds are formed, when the__________________?

   A. Fluid friction is zero
   B. Gravity force is less than the fluid friction
   C. Pressure forces equal gravity forces
   D. Sum of the fluid friction and pressure forces is equal and opposite to gravity forces

10. Slugging in a fluidised bed can be avoided by using_____________________?

    A. Tall narrow vessel
    B. Deep bed of solids
    C. Shallow beds of solids and proper choice of particle size
    D. Very large particles