EIAT Mechanical Comprehension 5

Question 1

Work is calculated as:

Accepted Answer

Force × distance

Answer

Work (W) = Force (F) × Distance (d); it measures the energy transferred when a force moves an object over a distance.

Question 2

A cam mechanism is used to convert:

Accepted Answer

Rotary motion into reciprocating linear motion

Answer

A cam converts the continuous rotational motion of a shaft into back-and-forth (reciprocating) linear motion of a follower.

Question 3

In a traction elevator, rope grip is maintained by:

Accepted Answer

Friction between the rope and sheave grooves

Answer

Traction drive relies on friction in the grooved sheave — rope tension and groove geometry (undercut or round) generate the tractive force.

Question 4

What effect does doubling the diameter of a pipe have on its cross-sectional area?

Accepted Answer

Quadruples the area

Answer

Area = π(d/2)²; doubling d gives π(d)² which is 4 times the original area, so flow capacity increases four-fold.

Question 5

An elevator cab weighs 3,000 lb and is lifted 40 feet in 20 seconds. The power required (ignoring losses) is approximately:

Accepted Answer

6,000 ft-lb/s (10.9 HP)

Answer

Power = Work/Time = (3,000 lb × 40 ft) / 20 s = 6,000 ft-lb/s; dividing by 550 gives ~10.9 HP.

EIAT - Elevator Industry Aptitude Test Practice Test