Module 2: Transport Review

The coefficient of friction is equal to which of the following relationships given that Θ is the inclines angle of repose?

• tan Θ

• mg cos Θ

• mg sin Θ

• FS cos Θ

An advantage of die casting is it

• produces a large grain size.

• can produce large castings.

• is ideal for small production runs.

• allows high production rates.

Answer explanation

The other three choices apply to sand castings.

A process least applicable to alloy steel is

• rolling

• forging

• extrusion

• sand casting

Answer explanation

Low to medium carbon steels are extruded whereas alloy steels tend to be more difficult to extrude and are generally processed in more significant tonnages by rolling, forging and casting.

Recrystallisation after hot work results in

• larger grains

• smaller grains

• grain growth

• none of the above

Semiconductors are usually classified as

• positive and negative

• intrinsic and extrinsic

• doped and non-doped

• valence and conduction

Answer explanation

The other three options could be used in a discussion of semiconductors but are not generally used as classifiers of the two basic groups.

Which of the components below does not contain a semiconductor?

• diode

• rectifier

• transistor

• none of the above

Answer explanation

All three contain semiconductors. A diode is composed of two semiconductors, a rectifier uses a number of diodes and a transistor is a sandwich of three semiconductors.

An advantage of AC power is

• it is used in the home

• the current and voltage alternate

• the power can be stored in a battery

• voltage can be easily transformed to higher or lower values

Answer explanation

A and B are true but are not advantages as such, while AC power cannot be stored in a battery.

When two different monomers are joined the product is known as

• an alloy

• a laminate

• a composite

• a copolymer

Artificial neural networks are starting to be used in vehicles to

• manage datbases

• connect with human brains

• replace humans as drivers

• improve systems by learning from 'experience'

A 10 kg object was moved and the reactive force was overcome at a value of 50 N. Determine the coefficient of static friction.

• 0.25

• 0.5

• 0.75

• 5