Using meter bridge, it is advised to obtain the null point in the middle of bridge wire. Why?
Text Solution
Verified by Experts
The error in the measured value of unknown resistance S using meterbridge wil be minimum, when the null point is obtained at the middle of meterbridge wire. In this situation, the end error of the bridge will become ineffective. To understand it, let `alpha` be the end resistance of left and right copper strips in meterbridge. Let unknown resistance R be in the left gap of meter bridge. If null point is obtained at the middle of bridge wire (i.e., `l = 50cm`) then `(S + alpha)/(R + alpha) = (100 -50)/50 = 1 or S = R` It means the effect of `alpha` gets cancelled. In this situation the bridge is most accurate ans sensitive. If the null point is not at the centre, there will be some error becasue S will then not be equal to R.
Topper's Solved these Questions
CURRENT ELECTRICITY
PRADEEP|Exercise Conceptual Problems|3 Videos
CURRENT ELECTRICITY
PRADEEP|Exercise Very short Q/A|7 Videos
COMMUNICATION SYSTEMS
PRADEEP|Exercise MODEL TEST PAPER-2|9 Videos
DUAL NATURE OF RADIATION AND MATTER
PRADEEP|Exercise Exercise|191 Videos
Similar Questions
Explore conceptually related problems
Why is it necessary to obtain the balance point in the middle of bridge wire ? Explain.
Accuracy of a metrebridge is maximum when the null point is obtained at the midpoint of the bridge wire. This is because
Answer the following : (a) Why are the connections between the resistors in a meter bridge made of thick copper strips? (b) Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire? ( c) Which material is used for the meter bridge wire and why?
A meter-bridge is based on the principle of
In an experiment of meter bridge, a null point is obtaining at the center of the bridge wire. When a resistance of 10 ohm is connected in one gap, the value of resistance other gap is
The resistances in the left and right gaps of a metre bridge are 10 Omega and 30 Omega respectively. If the bridge is balanced, then the distance of the null point from the centre of the wire is
Show that the percentage error in the measurement of resistance by a metre bridge is minimum when the null point is near about the centre of the wire.
In a meter bridge the null point is obtained at the middle point of the wire. If in one gap the resistance is 10 Omega , then the value of resistance in the other gap is :–
PRADEEP-CURRENT ELECTRICITY-Problems for Practice (B)
