Question

three 20 kilo ohms Resistors R1, R2, and R3 are in Series across an applied voltage of 120 V. What is the voltage drop across each resistor.

Answer 1

Resistance across resistors in <i>series</i>
= R1+R2+R3

Voltage across each resistor is proportional to the fraction of each over the total.

For <b>example</b>,
resistors R1=2,R2=1,R3=3, ohms are connected in <i>series</i> and subject to a voltage of 12 volts,
Resistance of resistors in series
R=R1+R2+R3=2+1+3=6

voltage drops
V1=(R1/R)*12=(2/6)*12=4 volts
V2=(R2/R)*12=(1/6)*12=2 volts
V3=(R3/R)*12=(3/6)*12=6 volts
Check: total = 4+2+6=12 volts, ok.

Answer 2

Rt = R1+R2+R3 = 20k + 20k + 20k = 60k Ohms. = Total resistance.

I = E/Rt = 120/60k = 2 mA(milliamps).

V1 = V2 = V3 = I*R1 = 2 * 20k = 40 Volts
Therefore, the voltage across each resistor is 40 Volts.

Answer 3

Thanks.. :)