1. The most economical speed for an electrical motor is about 1800 revolutions per minute.
a. True
b. False
2. It has been suggested that synchronous motors are more expensive to install than squirrel cage motors if the rating
exceeds 1 hp.
a. True
b. False
3. Laser light is directional.
a. True
b. False
4. Offset drives, such as V-belts, gears, and chain drives, can be lined up more easily than direct drives.
a. True
b. False
5. Five quantities must be known if the machinery is to be set up with the correct pulley sizes.
a. True
b. False
Name: Class: Date:
Unit 52 Direct Drives and Pulley Drives
6. Most electrically driven constant-speed machines operate at speeds below ____ rpm.
a. 1800 b. 2000
c. 2200 d. 2400
7. Induction motors are rarely used for operation at speeds below ____ rpm.
a. 500 b. 700
c. 900 d. 1200
8. Laser light has a single frequency with constant amplitude and ____.
a. phase b. wavelength
c. pulse d. head
9. The ways in which a laser can be used for aligning systems are limited only by ____.
a. the power of motors b. the laws of light
c. the ingenuity of the users d. light dispersion
10. A vertical drive can cause problems because ____ tends to pull the belts away from the lower sheave.
a. rotation b. gravity
c. speed d. wind
Name: Class: Date:
Unit 52 Direct Drives and Pulley Drives