##

## Aim:

To design Series RL circuit and find out the current flowing thorugh each component.

## Apparatus:

Resistor, Inductor, AC power source, ammeter, voltmeter, connection wire etc..

##

## Theory:

When we apply an ac voltage to a series RL circuit as shown below, the circuit behaves in some ways the same as the series RC circuit, and in some ways as a sort of mirror image. For example, current is still the same everywhere in this series circuit. V_{R} is still in phase with I, and V_{L} is still 90° out of phase with I. However, this time V_{L} leads I — it is at +90° instead of -90°.

For this circuit, we will assign experimental values as follows: R = 25Ω, L = 1 H and V_{AC} = 10 V_{rms}. We build the circuit and measure 9.29 V across L, and 3.7 V across R. As we might have expected, this exceeds the source voltage by a substantial amount and the phase shift is the reason for it.

The vectors for this example circuit are shown to the right. This time the composite phase angle is positive instead of negative, because VL leads IL . But to determine just what that phase angle is, we must start by determining XL and then calculating the rest of the circuit parameters.

This can be easily verified using the simulator, by creating the above mentioned circuit and measuring the current and voltages across the resistor and inductor.

#### Fig:1

### Applicatios

These circuits exhibit important types of behaviour so they are fundamental to analogue electronics. It has wide applications in Electronic filter topology and Piezo electric shunt damping system.