IN ANSWERING QUESTIONS 3-36 AND 3-37,
REFER TO FIGURE 3-E.
3-36. When a negative voltage is applied to the
proper cathodes in an LED display, a
number is formed. To produce the numeral
5 on an LED display, which of the
following diodes must have a negative
potential on their cathodes?
3-37. If an LED segment has an "8" displayed
and the negative bias is removed from
diodes F and C, what numeral will be
3-38. When replacing LED displays, which of
the following methods should you use to
ensure that the replacement display is of
the same type as the faulty display?
1. A visual inspection
2. A check of the schematic symbols
3. Both 1 and 2 above
4. A check of the manufacturer's number
3-39. The photodiode acts as what type of
1. Variable inductor
2. Variable resistor
3. Nonvariable inductor
4. Nonvariable resistor
3-40. When the photodiode is exposed to
an external light, what happens to
(a) resistance and (b) current?
1. (a) Increase
2. (a) Increases
3. (a) Decreases
4. (a) Decreases
3-41. To conduct, how must a photodiode be
1. Reverse biased
2. Forward biased
3. Either 1 or 2 above, depending on light
3-42. Photodiodes are useful in which of the
1. Computer card readers
2. Photographic light meters
3. Optic scanning equipment
4. Each of the above
3-43. Which of the following optoelectronic
devices provides increased, conduction for
a given light intensity?
3-44. To compensate for ambient light, a
phototransistor must have a total number
of how many leads?