3. The layout of drain systems can often be improved by the use of automatic pumps.
Condensate can be drained by gravity more readily to local receivers and then pumped
back to the engine room as required. What type of operated traps is above description?
(A) Mechanical trap
(B) Thermostatic trap
(C) Thermodynamic trap
(D) Vacuum trap
4. Which one is not the main function of detergent lubricating oil?
(A) Reducing wear of piston ring
(B) Preventing agglomeration and deposition in the engine
(C) Lowering pressure of combustion in engine
(D) Reducing wear of cylinder
10. A non-return valve allows flow in one direction only. What kind of valve is above
description?
(A) Check valve
(B) Gate valve
(C) Butterfly valve
(D) Globe valve
39. Which technical term is referred to as the zero-potential reference of an
electric/electronic system?
(A) Penetration
(B) Filtering
(C) Shielding
(D) Ground