1 When there is a sudden increase in drag coefficient on an airfoil as the free stream Mach number is increased beyond critical Mach number, (a) flow over the airfoil turns sonic (c) creation of...

1 When there is a sudden increase in drag coefficient on an airfoil as the free stream Mach number is increased beyond critical Mach number,

(a) flow over the airfoil turns sonic (c) creation of supersonic region occurs  on the airfoil surface

(b) flow separation occurs due to (d) none of these

2 The speed of hydraulic turbine under no-load conditions with guide vanes fully open is known as _________________________

(a) specific speed (c) runaway speed

(b) unit speed (d) critical speed