LAWS OF COMBINATION OF RESISTORS ( WHEATSTONE’S BRIDGE & POST OFFICE BOX ) Physics practical gseb std 11 & 12

Wheatstone's bridge

 LAWS OF COMBINATION OF RESISTORS

( WHEATSTONE’S BRIDGE & POST OFFICE BOX )

Experiment :- 3.1

AIM :-

You are given a Wheatstone Bridge and other necessary instruments.

Find the values of the unknown resistance Rx and Ry .

Now connect them in series and parallel respectively and measure their resultant resistances and test the laws of series and parallel connections.

PRINCIPLE :-

It works on the  principle of a balanced Wheatstone bridge.

Apparatus :-

Wheatstone-bridge (meter-bridge),

2 Volt Battery,

Rheostat,

Galvanometer, 

Jockey,

Key,

Resistance box(1 – 100  W),

Resistance coil.

Precautions

(1)   Make all connections tight.

(2)    Clean the ends of the connecting wire with a sand paper.

(3)    Plug keys of resistance box should be very tight.

(4)     Adjust the value of R from the resistance box such that null-point is obtained between 40 cm. and 60 cm.

Laws of combination of resistors

Wheatstone's bridge Apparatus

Wheatstone's bridge Line Diagram

Wheatstone's bridge Practical

Wheatstone's bridge Observation table

(2)   Condition :-

Connect unknown resistance R_y between  M – N.

 

Wheatstone's bridge Line diagram

Wheatstone's bridge line diagram

Wheatstone's bridge Practical

Wheatstone's bridge observation table 2

 (3)   Condition :-

Connect unknown resistance Rx & Ry in Series.

 

Wheatstone's bridge series connection condition 3

Wheatstone's bridge condition 3 Line diagram 

wheatstone's bridge practical

Wheatstones bridge observation table condition 3

(4) Condition :-

Connect unknown resistance in Parallel .

Wheatstones bridge parallel connection

Wheatstones bridge parallel connection practical

wheatstones connection conclusion