How to Calculate Unknown Resistance Using Meter Bridge

Step-by-Step Guide

1. 1

   Step 1: Check that the meter bridge wire is connected.

   If not, just connect both ends of the wire tightly.
   
   The apparatus has 5 places for the connections.
   
   All gaps for connections are found above the meter bridge wire; two on either sides and one in the middle.
2. 2

   Step 2: Imagine 5 dots plotted on a paper which are coplanar also imagine a line below it which is a little longer than the line which we can get if we join the points.

   The above connection is similar to this. , In the remaining gap, connect a galvanometer, high resistance and jockey all in series. ,,,,, note it down as L. calculate the average for R2 and R4 too let it be M. , Each time you can calculate the unknown resistance using the formula:unknown resistance(a)=known resistance(b)*L/M.
   
   The value is found to be the same for all values of known resistance.
3. 3

   Step 3: Connect a known resistance on one side and unknown resistance on the other this fills 4/5 gaps left for connections.

4. 4

   Step 4: Slide the jockey over the meter bridge wire and note down the reading for which you get zero deflection in galvanometer.

5. 5

   Step 5: Let it be R1 now put R2=100-R1.

6. 6

   Step 6: Similarly

7. 7

   Step 7: calculate another reading by interchanging the known and unknown resistances in the above circuit.

8. 8

   Step 8: Let the new readings be R3 and R4 where R3 is the length obtained for zero deflection and R4=100-R3.

9. 9

   Step 9: Add R1 and R3 and divide it by two.

10. 10

    Step 10: Repeat the above for various known resistance values.

Detailed Guide

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