Steam and Gas Turbines Multiple Choice Questions on “Disk Stresses and Blade Fastening”.
1. Rotating disks are subjected to _______
a) mechanical stress
b) thermal stress
c) mechanical & thermal stress
d) none of the mentioned
Answer: c
Clarification: Rotating disks are subjected to both mechanical and thermal stresses.
2. Internal pressure on the disk are due to _______
a) broken fittings
b) expanded fittings
c) shrink fitted on its mountings
d) none of the mentioned
Answer: c
Clarification: Internal pressure on disk is caused due to shrink fitted on its mountings.
3. Finite element analysis is done for rotating disk.
a) True
b) False
Answer: a
Clarification: Different temperatures are established when hot gasses are passed and hence finite element analysis is done.
4. High stresses in rotating disks are caused due to _______
a) excessive temperature
b) excessive rotating speeds
c) excessive temperature & rotating speeds
d) none of the mentioned
Answer: b
Clarification: High stresses in rotating disks are caused due to excessive rotating speeds.
5. Rotational disks deform due to ______________
a) uni symmetrical
b) multi symmetrical
c) axi symmetrical
d) none of the mentioned
Answer: c
Clarification: Deformation of rotational disks is axi symmetrical.
6. Gas turbine discs are made of _______
a) Chromium
b) Chrome-Nickel steel alloy
c) Nickel
d) None of the mentioned
Answer: b
Clarification: Chrome-nickel steel alloy is used to make gas turbine discs in general.
7. Contact at fastening between blade root and disk staple is ________
a) one dimensional
b) two dimensional
c) three dimensional
d) none of the mentioned
Answer: c
Clarification: Three dimensional contact is maintained at fastening between blade root and disk staple.
8. Some of the fasteners are _______
a) Bolts
b) Nuts
c) Keys
d) All of the mentioned
Answer: d
Clarification: Keys, Nuts and Bolts are some fasteners in turbine generator steam turbines.
9. ________ are used to secure some fasteners which have tendency to slip or slide away.
a) Bolts
b) Nuts
c) Washers
d) None of the mentioned
Answer: c
Clarification: Washers are used to lock fasteners which slip or slide away.
10. Bolts are _______ fasteners.
a) locking fasteners
b) threaded fasteners
c) frictional fastener
d) none of the mentioned
Answer: b
Clarification: Bolts are threaded fasteners as they have threading on them.