using the principle of wheatstone bridge, describe the method to determine the specific resistance of a wire in the laboratory. Draw the circuit diagram and write the formula used.


Connect the wire in left gap of the wheat stone bridge and resistance R in right gap of wheat stone bridge.

Touch the jockey in the left hand side and right hand side, galvanometer must show the opposite deflection.

Now slide the jockey from the left side on the wire and note the point at which galvanometer shows zero deflection.

Now note the length of this point from left side say this as l.
use the formula
X = l100-l×Rwhere X is the unknown resistance of wire and R is the unknown resistance is right gap.l is the balancing length.Specific resistance of the wireρ =X×πD24Lwhere D is the diameter of the wire and L is the length of the wire.
 

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