1. Homework for Diodes Page 1 of 3 Please circle your answer
Students Name:___________________________ Date:__________
Please circle your answer
Resistors that change with Temperature changes are called:
Broken ; b) Thermistors ; c) Variable ; d) sensors
The LDR varies its resistance with changes in ________ levels:
Light ; b) Water ; c) Sound ; d) Heat
Semiconductors are made by adding _______ to Silicon:
Water; b) copper ; c) impurities; d) rubber
A N-type semiconductor material contains excess _______:
Protons; b) electrons; c) Neutrons; d) Atoms
Adding impurities to silicon to produce a semiconductor is called ______:
Doping; b) Fixing; c) cheating
The layer formed at the junction of a diode is called the _______ layer:
a) Neutral ; b) common; c) Depletion; d) twilight

2. Homework for Diodes Page 2 of 3 Please circle your answer
Students Name:____________________________ Date:___________
Please circle your answer
7) If a Diode is conducting current it must be:
a) Broken ; b) Reverse-Biased ; c) Forward-Biased ; d) reversed
8) The semiconductor material LEDs are made from is:
Silicon ; b) old tires ; c) plastic d) Gallium-Arsenide
9) A LED is a special type of Diode: T F
10) LEDs need to be Forwarded-Biased to produce light: T F
11) A LED MUST be used with current-limiting resistor in series; T F
12) When the light on a LDR is increased, the resistance goes up: T F
13) The light output of a LED will Increase with Increasing current: T F
14) A Diode that is Reverse-Biased has a High resistance: T F
15) ‘Holes’ is the term used to indicate the Absence of electrons in a semiconductor material: T F

3. Homework for Diodes Page 3 of 3 Please circle your answer
Students Name:___________________________ Date:__________
Please circle your answer
16) The area of a diode with no net charge is called the _______:
Anode ; b) Depletion layer ; c) Cathode ; d) netural zone
17) Diodes Have Zero resistance when they are Forward-Biased:
True; b) Sometimes True ; c) False; d) Undetermined
18) If the temperature goes up on a Thermistor, the resistance:
Stays the same; b) goes up; c) goes down
19) Large current Diodes produce _________ when forward-biased:
Water; b) Smoke; c) Heat; d) noise
20) FSRs change resistance with changes in______:
a) Heat; b) Light; c) Strain d) sound