Resistor in Series Circuit

Resistors are used in circuit as load or control voltage and current though a path. To do those resistors are connected in various method such series, parallel, series-parallel combination. Series circuit combination used where low voltage loads or connected . So certain voltage can be dropped in series resistors. Further where voltage control method used such control fan speed using conventional fan regulator.

To connect resistors in series it is necessary to go through figure shown here. There are three resistors are used for formation series circuit. One end of resistor R1 connected with positive end of voltage source. another end of same resistor R1 connected with first end of second resistor. Then its second end with another resistor connected with third resistor and so on. In this method N-number of resistor can be connected in series connection. Finally last end of Nth resistor will be connected with negative terminal of voltage source.

Properties of Series Circuit

1. Total Resistance of the circuit will be sum of all resistor connected in the circuit

Total Resistance R_T = R₁+R₂+R₃+……………+R_n

2. Total applied voltage in the circuit will be equal to sum of the voltage drop across all resistor connected in it.

Total Voltage V_T = V₁+V₂+V₃+…………+V_n

3. Total current flowing through series circuit is equal to to current flowing through all resistor

Total Current I_T = I₁ =I₂=I₃=………….=I_n

4. Total resistance in the circuit will be more than large value of resistor connected in it
5. Voltage drop across any resistor is depends on value of resistor value. So more voltage will drop across large resistor and less voltage drop across small value of resistor.
6. Total power dissipated in the circuit is inverse sum of power consumed in all individual resistor.

Total Power Dissipated 1/P_T = 1/P₁+1/P₂+1/P₃+……….+1/P_n

Limitations of series circuit

1. If any single resistance broken in the circuit, further there will be no current flow in the circuit.
2. While short circuit of anyone resistor total resistance of the circuit will be decreased. Hence it will increase amount of current flow also increases
3. If one resistor is short circuit circuited remaining resistors in the circuit will be in operational.

Application of Series Circuit

1. In DC Motor speed control system series rheostat connected with armature or field winding for voltage control system
2. Fan regulator connected with fan for speed control system.
3. In decorative lighting bulbs are connected in series circuit.
4. In fluorescent lamp circuit choke connected with circuit for starting fluorescent lamp and maintain voltage once it is working.