Wein-Bridge is commonly used for the measurement of

Wein-Bridge and its Usage:

Definition: The Wein-Bridge is an electronic circuit predominantly used for the measurement of capacitance. It operates on the principle of balancing a bridge circuit, where the unknown capacitance is determined by comparing it with known components in the circuit. The bridge is named after Max Wien, who developed the concept for use in various measurement and oscillator applications.

Working Principle:

The Wein-Bridge consists of four arms in the form of resistors and capacitors. It is structured as follows:

• Two arms of the bridge contain resistors.
• The other two arms contain a combination of resistors and capacitors in series or parallel arrangements.

When an AC signal is applied to the bridge, the values of the resistors and capacitors are adjusted until the bridge reaches a balanced state. At this point, the output voltage across the bridge becomes zero, and the unknown capacitance can be calculated using the known values of the resistors and capacitors.

The balance condition for the Wein-Bridge is expressed as:

Z1 × Z4 = Z2 × Z3

Here, Z1, Z2, Z3, and Z4 are the impedances of the four arms of the bridge.

Advantages:

• High accuracy in capacitance measurement.
• Simple and reliable circuit design.
• Commonly used in laboratory instruments and audio frequency oscillators.

Applications:

• Measurement of unknown capacitance in electronic circuits.
• Used in audio frequency oscillators for generating sine waves.
• Implemented in filter design for signal processing applications.

Correct Option Analysis:

The correct option is:

Option 3: Capacitance

This is the correct answer because the Wein-Bridge is widely used for the measurement of capacitance. Its design specifically allows for precise determination of unknown capacitance values by balancing the bridge circuit and using known resistor and capacitor values. The working principle and formula for balancing the bridge make it a reliable tool for such measurements.