Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
KelvinтАЩs bridge consists of
Double bridge
Single bridge
Half bridge
Three fourth bridge
Double bridge
Kelvin's bridge is referred to as a 'double bridge' because it employs two sets of ratio arms to eliminate the effect of connecting lead and contact resistance. It is specifically designed to measure very low resistances (below 1╬й) with high precision.
Kelvin's bridge is referred to as a 'double bridge' because it employs two sets of ratio arms to eliminate the effect of connecting lead and contact resistance. It is specifically designed to measure very low resistances (below 1╬й) with high precision.
R=SтЛЕQPтАЛ тАФ Balance equation for Kelvin bridge when potential drops across leads are compensated
QPтАЛ=qpтАЛ тАФ Condition for eliminating the effect of lead resistance r
In a standard Wheatstone bridge, lead resistances introduce significant errors when measuring low values. Kelvin's double bridge overcomes this by introducing an auxiliary set of ratio arms connected to the potential terminals of the unknown resistor, ensuring the voltage drop across the connecting leads does not influence the balance equation.
Used for accurate measurement of resistances in the range of 10тИТ6╬й to 1╬й.
Uses four ratio arms: two main arms (P,Q) and two inner arms (p,q).
The 'double' refers to the two sets of ratio arms used to account for contact resistance.
Eliminates lead resistance errors
High accuracy for low resistance measurements
Complex circuit compared to Wheatstone bridge
Requires balancing two sets of arms
Measurement of resistance of copper conductors
Calibration of low-value standard resistors
Wheatstone bridge is suitable for medium resistance (1╬й to 100k╬й).
Option B (Single bridge) refers to a basic Wheatstone arrangement, which fails at low resistance due to lead drop.
A is correct тАФ Kelvin's bridge is termed a double bridge as it utilizes two pairs of ratio arms to minimize errors caused by lead and contact resistances.
Always remember: Wheatstone for Medium, Kelvin for Low, and Megger/Loss of Charge for High resistance measurements.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants