Plant Operator Selection System Test Plant Operator Selection System Mechanical Concepts 4

Question 1

An inclined plane is 10 feet long and 2 feet high. Ignoring friction, what force is required to slide a 200 lb object up the ramp?

Accepted Answer

40 lb

Answer

Mechanical advantage = length ÷ height = 10 ÷ 2 = 5; required force = 200 ÷ 5 = 40 lb.

Question 2

Which property of a material refers to its ability to return to its original shape after a deforming force is removed?

Accepted Answer

Elasticity

Answer

Elasticity is the ability of a material to recover its original dimensions after the applied stress is removed.

Question 3

A pressure gauge on a storage tank reads 50 PSIG. The local atmospheric pressure is 14.7 PSIA. What is the absolute pressure inside the tank?

Accepted Answer

64.7 PSIA

Answer

Absolute pressure = gauge pressure + atmospheric pressure = 50 + 14.7 = 64.7 PSIA.

Question 4

In a V-belt drive system, what is the PRIMARY reason for maintaining proper belt tension?

Accepted Answer

To prevent slippage and ensure efficient power transfer

Answer

Proper tension prevents the belt from slipping on the pulley sheaves, which would cause power loss, heat, and accelerated belt wear.

Question 5

A reciprocating (piston) compressor differs from a centrifugal compressor primarily in that it:

Accepted Answer

Uses reciprocating motion to compress gas in cylinders

Answer

Reciprocating compressors use back-and-forth piston motion in cylinders with inlet and discharge valves to compress gas.

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