**How Voltage divider rule works for DC circuit**

Lest we have a DC circuit and a constant voltage source VT and all resistors connected in

series the you can find voltage drop Vi using below formula

**Vj=VT*Rj/R1+R2+R3+R4…..**

Vj- voltage drop in resistor Rj in volts [V].

VT – the equivalent voltage source or voltage drop in volts [V].

Rj – resistance of resistor Rj in ohms [Ω].

R1 – resistance of resistor R1 in ohms [Ω].

R2 – resistance of resistor R2 in ohms [Ω].

R3 – resistance of resistor R3 in ohms [Ω].

R4 – resistance of resistor R4 in ohms [Ω].

**Lest take one Example**

We have a Voltage source of VT=50V is connected to All resistors in series, R1=20Ω, R2=20Ω,R2=10Ω

So we have to Find the voltage drop on resistor R3.

V2 = VT × R3 / (R1+R2+R2) = 50V × 10Ω / (20Ω+20Ω+10Ω) = 10V

**How Voltage divider work for AC circuit**

The voltage drop Vi in load Zi is given by the formula:

Lest we have a AC circuit and a constant voltage source VT and loads are connected in

series the you can find the voltage drop Vi in load Zi using below formula

Vj=VT*Zj/{Z1+Z2+Z3+Z4…}

Vj- voltage drop in load Zj in volts [V].

VT – the equivalent voltage source or voltage drop in volts [V].

Zi – impedance of load Zi in ohms [Ω].

Z1 – impedance of load Z1 in ohms [Ω].

Z2 – impedance of load Z2 in ohms [Ω].

Z3 – impedance of load Z3 in ohms [Ω].

At any time current flows across a parallel path it gets divided because of presence of electron in various path.

If The flow path having low resistances will supply less resistance to current flow and more current will move across that path.

In simple word you can say that if current path having high opposition then current flow will

less across this path.

Lets take one more example we have a circuit which having voltage source of 20 volt, and three resistors 5 ohm,10phm and 15 ohm connected in series and with load of 2 ohms.

**using volatge divider formula**

V1(in R1) = V(voltage source)*(R1/Requation), Requation= R1+R2+R3+Rload= 5+10+15+2= 32ohms.

V1(in R1) = 20*5/32= 3.125 volt.

V2(in R2)= 20*R2/41= 20*10/32=6.25volt.

V3(in R3) = 20*R3/41=20*15/32= 9.375 volt.

V4(in R4) = 20*R4/41= 20*2/32= 1.25volt.

V= V1+V2+V3+V4= 20 volt

**Tats voltage division rule..**

In simple words you can explain Voltage divider as “Voltage divider are circuits which can be used to decrease the voltage in the circuit”

There are numerous biasing method like collector feedback,fixed bias, emitter feedback,voltage divider bias etc.But from all above list voltage divider bias is found to be the most acceptable.

and voltage divider bias the most used biasing method .

**Benefit of voltage divider**

If we want to reduce the voltage we can use voltage divider.

**Let’s take one example example:**

20V has to reduced 2V, then we use 1:10 ratio voltage divider. But higher side 20V to 200V you can not do.

- Voltage dividers are handy for mainrtaing the output voltage of linear regulators.
- Voltage dividers are also handy for dividing down a high voltage to the input range of an A/D inside a micro-controller.

**How to calculate voltage divider**

Vout=Vin*R2/R1+R2

=9*1000/1000+1000

=9*1000/2000

=4.5V

Vout=Vin*R2/R1+R2

=12*5/5+2

12*5/7

8.57V

Vout = Vin * R2/R1+R2

Vout/Vin = R2/R1+R2

Vin/Vout = R1+R2/R2

Vin/Vout = R2/R1+R2

Vin/Vout = R1/R2+R2/R2

Vin/Vout = R1/R2+1

Vin/Vout-1 = R1/R2

R2 = R1/(Vin/Vout-1)

R2 = 1000/(12/9-1)

R2 = 3000=3k

Vout = Vin*R2/R1+R2

1 = 6*5/5+R1

1/6 = 5/5+R1

5+R1=5/1/6=5*6

5R1 = 30

R1 = 25k