Darlington Pair with LDR

but changed the
10 k resistor - 1k resistor
10k pot - 1k pot

Darlington pair

 










470 instead of 560
68k instead of 100k

Heres what I made

LDRs and Potentiometers

Q1. How does the resistance on the LDR change with light illumination on the LDR?
Q2. Why do we need a protection resistor here?
Q3. Why do we always need a protection resistor for LEDs?
Q4. What are the three legs for on the 'Pot'?
Q5. What is the difference between a 10K pot and a 1K pot?
Q6. Why would a 10K pot be better for this LDR than a 1K pot?
Q7. What is a thermistor?
Q8. What is the resistance range of the LDR?

Resistor -
             Resistance 560 Ω
Potentiometer -
             Ressistance Code 120 Ω
             Ressistance - 1k

1) Normal light - 1.56 Ω
   light right on top - 0.30 Ω
    light very close - 0.56 Ω
    short distance - 0.63 Ω
    medium distance - 0.99 Ω 
    long distance -  1.44 Ω
    finger over the LDR - 3.25 Ω

2)  your using a protection resistor to protect the potentiometer . Because its small like you heat up quickly. and if it has a low ressistance and a high current so it'll blow.

3) to keep the current high so the resisstor doesnt blow. (to keep a high resiance so a low current)

4) there are 3 legs
- the top middle one is input
the bottom 2 (bottom left and bottom right) are both output (ground)
 
5) one has a bigger maximum resistance
 
6) to be able to have a bigger maximum resistance
 
7) A thermistor is a type of resistor whose resistance varies significantly with temperature, more so than in standard resistors.

8) the range is 20 - 20000k Ω

Questions from book

pg 54

9) 1.22 V
10) 3.050 V
11) 3.54 V
12) 22.5 V
13) 41.612 V
16) R1 - 180 Ω
      R2 - 180 Ω
17) R1 - 40 Ω
       R2 - 60 Ω
19) 24.05 Ω
20) 80 V

V=IR equation practice

Here's some practice

questions from text book

9) 1.22 V
10) 7.77
11) 3.54

Parallel

Here a photo of my parallel curcuit.