1. 1. Measurement of unknown resistance using Wheatstone Bridge
At balanced Condition:
PX=QR
X=(Q/P)*R Ohm
No. of Obs.
P/R
Multiplier Q/P
Value of R (Ohm)
Value of X (Ohm)
Average of X (Ohm) 1 2
0.1 3
0.01

2. To determine the self inductance of a coil by Anderson bridge.
Apparatus Used: Anderson bridge, connecting wires, Head phone.
Formula Used: The following formula is used for the determination of self inductance of coil.
DC source with G
AC source with headphone/oscilloscope
Now vary 𝑟 keeping the same value of R,
so that no sound is heard in Headphone
Note the value of 𝑟
Step-1: Now vary R, keeping r equal to zero, so that deflection in galvanometer becomes
zero. This is a DC balancing. Note this value of R.

3. Final value of unknown L :

4. Use of Potential Transformer and Current Transformer
Use of Potential Transformer at no load condition:

5. No. of Obs.
Turns ratio
Secondary voltage
(rms) (Volt)
Unknown Primary Voltage
rms (volt) 1
4:1 2 3 4 5

6. Use of Current Transformer at zero load condition:

7. No. of Obs.
Turns ratio
Secondary Current
(rms) (A)
Unknown H.T. Current
rms (A) 1
1:100 2 3 4 5