Here is the "Electrician's Mate 3 - Navy Training Courses" (NAVPERS 10548)
in its entirety (or will be eventually). It should provide one of the Internet's best
resources for people seeking a basic electricity course - complete with examples worked
U.S. GOVERNMENT PRINTING OFFICE; 1949
CHAPTER 15 QUIZ
1. Complete the following statements:
(a) The size of a Navy searchlight depends on the diameter of the
(b) The 36-inch and 24-inch light have a __________ source of light.
(c) The 12-inch
light has an __________ light source.
(d) 36-inch searchlights are used primarily for __________.
(e) 24-inch searchlights are used primarily for __________.
(f) 36-inch light have __________ for
elevation and train.
(g) A navy searchlight must:
1. Have a beam free of __________.
2. Have a beam of __________ color.
(h) Most Navy searchlights can:
through __________ degrees.
2. elevate up to __________ degrees.
3. depress down to
2. Complete the following statements:
(a) To start a carbon arc the carbon
electrodes must first __________.
(b) As the arc electrodes are drawn apart current is conducted across
gap by carbon __________.
(c) The crater is a depression in the positive carbon in which
(d) The crater must be positioned at the __________ of the searchlight reflector.
3. What is the
difference between high intensity and low intensity arcs?
4. Why must high intensity arcs be ventilated at all times?
5. How is power brought into the light
to permit rotation of searchlights in train?
6. Complete the following statements:
searchlights consist of:
1. A __________ to house the light source and reflector.
2. __________ to support the drum so it can be elevated.
3. A __________ to support the trunnion
arms so they can be rotated to train
(b) The searchlight drum has:
1. A __________ for the main body.
2. Access __________ to get at the lamp and
3. __________ motor to prevent overheating of the lamp.
4. Arc __________
screen to indicate condition of the arc.
(c) The arc lamp consists of:
1. A __________ to
support the carbon feed mechanism.
2. A __________ to support, rotate, and feed the positive
3. A metal __________ or obduratior to keep the heat of the arc from the
(d) The arc lamp has automatic mechanisms for
1. Forced draft __________.
2. Positive carbon __________.
3. __________ of positive carbon.
Negative carbon __________.
5. Starting the __________.
(e) The positive carbon is
automatically fed forward to keep the luminous vapor of
the arc at the __________.
positive carbon is automatically fed forward by a motor controlled by
a __________ switch exposed to
heat from the arc.
(g) The positive carbon must be continuously rotated to keep the arc crater __________.
(h) The positive carbon is constantly rotated by the __________ motor.
7. Complete the following
(a) The reflector of a searchlight is a mirror of __________ shape which collects the
light from the arc and reflects it in a parallel beam.
(b) Reflectors are made of:
1. Optical glass coated with __________.
2. Metals such as __________.
(c) In cleaning
reflectors always wipe from __________ __________.
8. Complete the following statements:
Shutters are used to __________ the light beam while the lamp is on.
(b) The iris shutter is too
__________ for signaling.
(c) The vane type shutter is used for signaling because of its __________.
9. Complete the following statements:
(a) In a current control negative feed, the feeding of the negative
carbon is controlled
by balancing the pull of a solenoid, energized by the __________ current, against
the tension of a spring.
(b) In a current control negative feed, when the solenoid pull and spring
balance, the negative carbon ______ feeding.
(c) In a current control negative feed
system, increasing spring tension
will __________ arc length.
10. Complete the following statements:
(a) In a voltage control negative feed, the feeding of the
negative carbon is controlled
by balancing the pull of a solenoid energized by voltage drop across the
against a spring tension.
(b) In a voltage control negative feed, when the solenoid
pull and spring tension balance,
the negative carbon __________ feeding.
(c) In a current
control negative feed system, increasing spring tension
will __________ arc length.
11. Complete the following statements:
(a) To keep the positive crater from burning off on one side
adjust the __________
between negative carbon and positive carbon.
(b) When carbon brush
pressure is properly adjusted it takes a pull of __________
ounces to slip the carbons out of the head
with feed rollers raised.
(c) Positive carbon projection must be adjusted to assure proper __________.
(d) Arc length is adjusted by changing spring tension of the __________ carbon feed.
(e) To adjust lamp
focus, move the lamp mechanism toward or away from
12. Complete the following
(a) Search light carbons will last:
1. 24-inch, __________ minutes.
2. 36-inch, at 190 amperes, __________ minutes.
(b) After renewing carbons operate light for
about __________ minutes to form
(c) If reaming positive or negative noses
while hot, never allow reamer to __________,
to prevent reamer sticking as metal cools.
1. Use mixture of 3 ounces __________ to 1/2 pint __________.
Polish from __________.
3. In polishing never use motion.
(e) In lubricating lights, never
use grease or oil on negative or positive __________.
13. Name the tests, inspections and cleaning to be
CHAPTER 15 ANSWERS
1. (a) reflector
(b) carbon arc
(c) incandescent light
(d) fire control
(f) remote control
(g) 1. flicker
2. bluish white
(h) 1. 360
3. 20 or 40
2. (a) contact
3. High intensity have smaller diameter
carbons and heavier currents
4. To prevent overheating
5. By slip rings and brushes
or by flexible cables
6. (a) 1. drum
2. trunnion arms
(b) 1. barrel
(c) 1. column
2. positive head
(d) 1. ventilation
7. (a) parabolic
(b) 1. silver
(c) center out
8. (a) shut off
9. (a) arc
10. (a) arc
11. (a) angle
(b) 8 to 10
12. (a) 1. 105
(d) 1. chalk, alcohol
2. center out
13. See lists in chapter 15