Can anyone help me find the input resistance of the circuit? I have been stuck for many hours and can't solve it.

I find the equivalent resistance of the circuit by applying a voltage source at the input and solve for the current I.

The input resistance:

Rin = V/I

However, I don't know why this method doesn't work.

Suppose I have two circuits which consist of a battery, a light bulb(with very high internal resistance in circuit A, very low in B) and the wire.

Circuit A:

I = 1.60217657 × 10^-20 Amps (Single electron every 10 seconds!)
Voltage = 10^21 Volts
Internal Resistance of the Bulb: Very High (it's an imaginary bulb anyway:P)

Circuit B:

I = 10^21 Amps
Voltage = 1.60217657 × 10^-20 Volts
Internal Res

Hey guys, I need help in finding the thevenin resistance of a circuit. I'm mostly having trouble telling whats in series and whats in parallel in the circuit.

Hi,

I try to make a simple electronic circuit.
So I have an instrument (medical ophtalmoscope) that contains a light bulb 10w, 6v. The adapter is noted 6v, 1.7A . I want to bypass the small rechargeable battery pack that isnt working well. So I want to dim my bulb using a potentiometer.

Hi Everyone,

I have a quick question. I understand in a series RLC circuit that at resonance, the reactances of the inductor and capacitor cancel out.

I need something like a voltage follower circuit, only instead of a comparator duplicating voltage, it duplicates resistance.

I have 2 computer modules that measure resistance by outputting 5v and then reading the value that does not drain through a sensor which varies resistance based on conditions that it senses.

I'm very new to electronics and am playing around with different combinations of resistors and LEDs trying to master the concepts behind series and parallel circuits.

Hello

I`m designing an automated greenhouse, using PIC18f4520 as the processor.
The circuit contains, the PIC circuit including:
LMB402CFC as the LCD
a 3*4 Keypad.

As input to the circuit, I have three different sensors,

LDR
LM35DZ
Soil Moisture sensor

As output to the circuit, I have four different actuators:

Fan
Heater
LED light,
Sprinkler

The outputs function under high voltage of 220V.

we know voltage divider bias circuit gives the fraction of the input voltage.i seen in a book that with choosing any one of the resistance has negative ,we achieve amplification.what does that negative resistance mean.how does it affect the circuit.explain me basically