Question

What are the advantages of kelvin double bridge to wheatstone bridge for small resistances?

Answer 1

Explanation:

What is the necessity of using the Kelvin double bridge in place of the Wheatstone bridge for the measurement of low resistance? Because by using Kelvin's Double Bridge, your end result i.e. the value of unknown resistance will not be influenced by resistances of connecting lead.

Answer 2

Advantages of Kelvin double bridge to Wheatstone bridge:

• Kelvin double bridge is a modified version of the Wheatstone bridge and hence a better version.
• Using a Wheatstone bridge, one can measure resistances either equal to or greater than 1ohm.
• Whereas using a Kelvin bridge, resistances ranging from 1 to 0.000001 ohms can be measured with high accuracy.
• When a Wheatstone bridge is used along with a galvanometer, the resistance values vary and hence lack accuracy.
• But a Kelvin bridge works well along with a galvanometer.
• Moreover, the Kelvin bridge has very high sensitivity and also uses very less power.