A gas turbine engine turbine section may employ active clearance control:

A: as a method of attaching the stators and rotors to the hub of the disc.
B: in order to cool the disc.
C: in order to reduce “creep” in the blades.
D: to provide enhanced clearances between the blade tips and the casing.









Answer: D

The distance between a NAVSTAR/GPS satellite and receiver is:

A: calculated from the Doppler shift of the known frequencies
B: determined by the time taken for the signal to arrive from the satellite multiplied by the speed of light
C: calculated, using the WGS-84 reference system, from the known positions of the satellite and the receiver
D: determined by the phase shift of the Pseudo Random Noise code multiplied by the speed of light









Answer: B