Inductance is measured by,

The correct option is Maxwell bridge.

Let us look at the applications of the various electrical bridges given in the options to understand their functions:

1. Maxwell Bridge:
Maxwell's bridge (specifically Maxwell's inductance-capacitance bridge) is used for the measurement of self-inductance. It measures the unknown inductance of a coil by comparing it with a known standard capacitance.

2. Schering Bridge:
This AC bridge is primarily used for the measurement of capacitance, dissipation factor, and dielectric properties of insulators.

3. Kelvin Bridge:
This is a DC bridge designed for measuring very low resistances (typically less than 1 ohm) with high accuracy by eliminating the effect of lead and contact resistances.

4. Wien Bridge:
This bridge is used for the measurement of frequency (especially in the audio range) and is also used as a frequency-determining element in audio oscillators.

Therefore, inductance is measured by the Maxwell bridge.