I am trying to verify voltage drop across a resistor as seen on my multimeter with basic ohms law calculations.
As shown in below circuit (from Electronics for DUMMIES). The multimeter shows a voltage drop of 6V at 1M ohm resistor. However that is not what my math shows and I think something is wrong with my maths. Here is how I am doing it
Vb=9V
First Find total Resistance of circuit
R1=1 M ohms= 1000000 ohms
R2=10 k ohms = 10000ohms
R3=470 ohms
R1 and R2 are in series with each other but both combined are in parallel to R3, so
Rtotal = (R1+R2)||R3 = (1000000+10000)||470
= 1010000 || 470
= (1010000 x 470)/(1010000 + 470)
=474700000/1010470
=469.7813888586499=469.7
Now to find Total Current
I=9V/469.7ohms
= 0.019 Amps
Voltage drop at R1
V1=0.019 x 469.7 =across 8.9V R1(multimeter1 showsM 6ohms)
Current through R1
I=8V1=0.9V019 /x 1000000 ohms
=0.0000089243= 19000(multimeterThis howscant 0.0000061be right)
Did I miss anything?
The NPN transistor is BC546B, which is acting as an amplifier