Experiment Description

Experiment

Experiment E17    Variation of Current and Phase with Frequency in CR and LR Circuits

Objectives
  • Study the variation of capacitive reactance with frequency
  • Study the variation of inductive reactance with frequency
  • Compare the two reactances in response to frequency change
  • Study the phase relationship between current and applied voltage in CR circuit
  • Study the phase relationship between current and applied voltage in LR circuit
Description
In this activity, you will study how the current in CR and LR circuits varies with frequency. You will also use a double beam CRO to study the phase relationship between the output voltage and current drawn from a power supply.

In Experiment 1, you will study the reactance of a capacitor. You will vary the frequency over a wide range and replace capacitors of different capacitance.

In Experiment 2, you will study the reactance of an inductor. You will vary the frequency over a wide range. You will also change the inductance of the inductor by inserting soft-iron core into the coil.

In Experiment 3, you will compare the freqency response of capacitor and inductor directly. You will notice the change in illumination of the light bulbs as the frequency is varied over a large range.

In Experiment 4, you will study the phase relationship of two voltages by the use of a dual trace CRO.

In Experiment 5, you will study the phase relationship of two voltages. Here, you will use an inductor instead of a capacitor.
Apparatus
coil (1100-turn) [1]
double C-cores with clip [1 pair]
capacitor (0.1, 4.7, 47, 470, 1100, 2200 mF) [1 each]
resistor (2 kOhm) [1]
light bulb (1.25 V) [2]
signal generator [1]
double beam CRO [1]
microphone/loudspeaker [2]
capacitor (0.47 mF) [1]
coil (120-turn) [1]
Experiment