Deck 3: Electrical Power and Energy

Question 1

With direct drive, the driving machine and the driven machine may be mounted on the same shaft, or a(n) ____ may be used.

A) reducer
B) pulley
C) shaft coupling
D) gear shaft

Answer 1

C

Question 2

Electrical energy is the product of power and time.

Answer 2

True

Question 3

Power is a measurement of the rate of doing work.

Answer 3

True

Question 4

When using a PIRE wheel, you should select a formula in the quadrant of ____.

A) Power
B) the unknown variable
C) Resistance
D) a known variable

Question 5

Work equals force times ____.

A) current
B) power
C) energy
D) distance

Question 6

Which is not an example of a type of drive?

A) chain on sprocket
B) gear assembly
C) pulley
D) electric motor

Question 7

Electrical power, in Watts, can be expressed as the product of current, in Amperes and electrical pressure, in Volts.

Question 8

Energy loss means that energy is destroyed or consumed.

Question 9

With which type of drive will the driven gear rotate in the opposite direction from the driving gear?

A) chain drive
B) two-gear drive
C) three-gear drive
D) direct drive

Question 10

Efficiency is the ratio of the unused power output to the total power input.

Question 11

How much power is dissipated by an electric oven if 30 A flows through a resistance of 10 ohms?

A) 9.2W
B) 7.52kW
C) 9kW
D) 9000 kW

Question 12

What is one possible downside of oversizing a motor?

A) increased energy usage
B) excessive motor heating
C) insulation breakdown
D) tripping overcurrent devices

Question 13

The ____ of a motor is the amount of torque developed at the instant the motor is energized.

A) starting torque
B) opening torque
C) initial torque
D) rated load torque

Question 14

A(n) ____connected in series with a motor will both limit and control the starting current.

A) alternator
B) torque converter
C) rheostat
D) thermostat

Question 15

Heat energy can be measured in ____.

A) degrees Celsius
B) British thermal units
C) ohms
D) watts