1. Two pinions of a gear system driven by the same worm will rotate
A. in the same direction as the worm.
B. at right angles to each other.
C. at a higher speed than the worm.
D. in opposite directions.
2. If the driven shaft and the drive are at the same angle but turn in opposite directions, the gearing system is called a
A. worm drive.
B. chain drive.
C. gear and pinion drive.
D. belt drive.
3. When a resistor and capacitor are placed in series, the circuit which results forms a(n)
A. RC time constant.
B. filter.
C. transistor supply.
D. IC regulator.
4. Reciprocating motion in an appliance is obtained from a rotating motor shaft with the aid of
A. a worm and a gear.
B. two gears and a pinion.
C. a counterweight on the gear.
D. an eccentric stud on the gear.
5. Why does an electric knife have a nylon gear and a steel worm?
A. To make the worm last longer
B. To eliminate lubrication of the worm
C. To reduce the load on the worm
D. To make the worm easier to replace
6. Which one of the following lubricants is recommended for use in gearboxes?
A. Light oil
B. Motor oil
C. Cream grease
D. Automobile grease
7. The line cord of a vacuum cleaner must be of the
A. jacketed type.
B. grounded type.
C. cotton-covered type.
D. zip type.
8. What type of speed control system uses a wire-wound potentiometer?
A. SCR
B. TRIAC
C. Free-running oscillator
D. Rheostat
9. If the motor in a geared appliance has a rated speed of 3600 rpm and a gear ratio of 6 to 1, the driven gear will turn at a speed of
A. 600 rpm.
B. 1800 rpm.
C. 3600 rpm.
D. 21,600 rpm.
10. What is the major disadvantage of a free-running oscillator used to trigger an SCR or TRIAC?
A. Limited high-speed operation
B. Limited low-speed operation
C. Excessive motor noise
D. Early motor failure
11. Modern full bag indicators use what type of sensing component?
A. A spring-loaded piston
B. A spring-loaded vane
C. A compression switch
D. A pressure differential switch
12. What is the typical breakover voltage for a DIAC used in an electronic control circuit in which 120 VAC is used with a power output semiconductor device?
A. 6
B. 12
C. 32
D. 70
13. A wet-carpet cleaner that carries its own water supply has water pressure created by a
A. manual valve.
B. solenoid valve.
C. motor-driven pump.
D. faucet mixing valve.
14. What type of device may be used to prevent a food processor’s motor from being damaged by excessive current?
A. A potential relay
B. A current relay
C. A centrifugal governor
D. A DIAC
15. Dull blades of an electric knife should be sharpened with
A. an oilstone.
B. a flat file.
C. a bench grinder.
D. a pattern file.
16. What component of a wet/dry vacuum cleaner is not present in a typical canister-style residential cleaner?
A. A high-speed universal motor
B. A single-pole, single-throw ON/OFF switch
C. A blower port for exhaust air
D. A float switch
17. Vacuum strength is rated in terms of
A. rheostat capacity.
B. cm or in. of water lift.
C. horsepower.
D. torque.
18. The purpose of a capacitor unit in a vacuum cleaner is to
A. suppress radio-frequency interference.
B. increase the motor starting torque.
C. reduce the voltage applied to the rectifier.
D. eliminate brush arcing.
19. In what order does the air flow in a canister vacuum cleaner pass through the following components?
A. Motor, filter, fan, and bag
B. Filter, motor, bag and fan
C. Bag, filter, fan, and motor
D. Bag, motor, fan, and filter
20. A vacuum cleaner can operate at two different speeds because it uses two
A. armatures.
B. starting switches.
C. fan blades.
D. field-coil lengths.
21. What is the name of the SCR or TRIAC triggering system that triggers the output device at the same point on each AC cycle?
A. Phase-regulated switching
B. Locked-pulse switching
C. Zero-crossing switching
D. Full-cycle switching
22. Which one of the following statements is TRUE concerning an upright vacuum cleaner?
A. An upright cleaner uses a two-stage filter to prevent motor dirt buildup
B. Upright cleaners are only available in single-speed models
C. Many upright cleaners use a top-fill dust and dirt collection system
D. Upright cleaners use a gear-drive agitator system
23. What would be the most likely cause of an agitator belt showing excessive wear on one side of the belt?
A. Bent drive shaft
B. Dragging agitator bar
C. Improper belt tracking
D. Broken ribs in belt
24. What is the most probable cause of weak suction in a vacuum cleaner if the hose, the bag, and the filter are NOT clogged?
A. Unbalanced fan blades
B. Worn brushes and bearings
C. A shorted armature
D. Leaking gaskets and fittings
25. Why is mechanical feedback of motor speed needed in some large food processors?
A. To prevent motor runaway to an unsafe speed
B. To reduce the overall cost of the appliance
C. To prevent motor stalling in high-torque situations
D. For exact low speed operation without clogging