671. Choose the wrong statement ?
A. The center of buoyancy is located at the center of gravity of the displaced liquid
B. For stability of a submerged body, the center of gravity of body must lie directly below the center of buoyancy
C. If e.g. and center of buoyancy coincide, the submerged body must lie at neutral equilibrium for all positions
D. For stability of floating cylinders or spheres, the e.g. of body must lie below the center of buoyancy
E. All floating bodies are stable
672. Pick up false statement?
A. For petrol and large gas engines, quantity governingds preferred
B. In quantity governing, air fuel ratio is almost constant and quantity of charge is changed depending on load
C. In hit and miss governing, fuel supply is completely cut off during one or more number of cycles
D. In quality governing, quantity of fuel is varied to suit the load and total charge of air is varied
E. For close regulation of speed, combination of both quality and quantity governing is used
673. At very low temperature, the melting and boiling temperatures become equal. This temperature is____________________?
674. The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is__________________?
D. may be less or more depending on temperature
675. The amount of radiation mainly depends upon the
A. nature of the body
B. temperature of the body
C. type of surface of the body
D. all of these
676. Carbonation of coal is the process of________________________?
A. pulverising coal in inert atmosphere
B. heating wood in a limited supply of air at temperatures below 300°C
C. strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel
D. binding the pulverised coal into brick-ettes
E. enriching carbon in the coal
677. Heating of dry steam above saturation temperature is known as_____________________?
D. latent heat
E. super tempering
678. The maximum or minimum value of the swaying couple is
A. ± c.m.ω2.r
B. ± a(1 – c)m.ω2.r
C. ± (1 – c)m.ω2.r
D. ± 2a(1 – c)m.ω2.r
679. For an involute gear, the ratio of base circle radius and pitch circle radius is equal to
A. sin φ
B. cos φ
C. sec φ
D. cosec φ
680. A chain consisting of four links and four joints is called a kinematic chain.