1. Electric brakes have been in use since the early 1900s.
a. True
b. False
2. An electric brake consists of three friction surfaces, or shoes.
a. True
b. False
3. The coil leads of an AC magnetic brake are normally connected directly to the motor terminals.
a. True
b. False
4. For AC shoe brakes, the operating coils are shunt wound for across-the-line connections and series wound for
connecting in series with DC motor armatures.
a. True
b. False
5. Series-wound brakes may be used for metal processing applications.
a. True
b. False
Name: Class: Date:
Unit 49 Electric Brakes
6. Electric brakes are also known as magnetic brakes, friction brakes, and ____ brakes.
a. surface b. mechanical
c. shoe d. wear
7. In a magnetically operated brake, the shoes are held in a released position by a magnet ____ the magnet coil is
energized.
a. even if b. until
c. unless d. as long as
8. Magnetic brakes are suitable for ____ loads.
a. high-inertia b. centrifugal
c. low-inertia d. centripetal
9. Brakes range in size from approximately 1 inch to ____ inches in diameter.
a. 6 b. 12
c. 30 d. 60
10. An advantage of the use of DC brakes for shunt-wound operation is ____.
a. little AC chatter b. laminated magnets are used
c. short armature movement d. armature is cast of iron
Name: Class: Date:
Unit 49 Electric Brakes