IBEW Mechanical Reasoning Principles 5

Question 1

Two identical cylinders contain gas at the same pressure. Cylinder A is kept at room temperature; Cylinder B is heated. Which cylinder has higher gas pressure after heating?

Accepted Answer

Cylinder B

Answer

At constant volume, gas pressure is directly proportional to absolute temperature (Gay-Lussac's Law), so the heated cylinder has higher pressure.

Question 2

A motor drives a pump through a flexible coupling. The flexible coupling's primary purpose is to:

Accepted Answer

Compensate for minor shaft misalignment and absorb shock loads

Answer

Flexible couplings accommodate small angular or parallel misalignments and dampen vibration and shock between connected shafts.

Question 3

A ball rolls down a frictionless ramp and then along a flat surface. On the flat surface, the ball will:

Accepted Answer

Continue at constant speed indefinitely

Answer

On a frictionless flat surface there is no net horizontal force, so Newton's first law dictates the ball continues at constant velocity.

Question 4

A torque wrench is set to 80 ft-lb. The technician applies force 2 feet from the bolt center. How much force must be applied?

Accepted Answer

40 lb

Answer

Torque = force × distance; 80 ft-lb = F × 2 ft, so F = 40 lb.

Question 5

In a three-phase electrical system, phase conductors carry current that is offset in time by:

Accepted Answer

120 degrees

Answer

In a balanced three-phase system, each phase is displaced 360°/3 = 120° from the others.

IBEW - Aptitude Test Practice Test

IBEW - Aptitude Test Practice Test

IBEW Mechanical Reasoning Principles 5