Mechanical Reasoning Principles Flashcards

A flywheel is used in machinery primarily to:

Answer: Store rotational energy and smooth out speed fluctuations

A flywheel's rotational inertia stores kinetic energy, damping speed variations between power strokes.

A screw has 16 threads per inch. How far does a nut advance along the screw for each complete turn?

Answer: 1/16 inch

Each full revolution advances the nut one thread pitch; pitch = 1 ÷ threads per inch = 1/16 in.

Which type of bearing is best suited for handling both radial and axial (thrust) loads simultaneously?

Answer: Angular contact ball bearing

Angular contact ball bearings are specifically designed to carry combined radial and axial loads due to their angled contact geometry.

A centrifugal pump will lose its prime when:

Answer: Air enters the suction side of the pump

Air introduced to the suction side breaks the liquid column, preventing the impeller from creating the pressure differential needed to move water.

Heat travels through the copper wires in an electrical panel primarily by:

Answer: Conduction

Conduction is heat transfer through direct contact between molecules within a solid material like copper wire.

A worm gear set has a 40-tooth worm wheel and a single-start worm. What is the gear ratio?

Answer: 40:1

For a single-start worm, the gear ratio equals the number of worm wheel teeth; here that is 40:1.

A 12-volt battery is connected to a light bulb through a switch. The circuit is open (switch off). What is the voltage across the switch?

Answer: 12 volts

In an open circuit no current flows, so there is no voltage drop across the bulb; all 12 V appears across the open switch.