Marwari college Darbhanga
Subject---physics (Hons)
Class--- B. Sc. Part 2
Paper –04. ; Group—A
Topic--- Anderson Bridge
Lecture series ---65
By:-. Dr. Sony Kumari,
Assistant professor
Marwari college Darbhanga
Anderson Bridge
The Anderson’s bridge gives the accurate
measurement of self-inductance of the circuit. The bridge
is the advanced form of Maxwell’s inductance capacitance
bridge. In Anderson bridge, the unknown inductance is
compared with the standard fixed capacitance which is
connected between the two arms of the bridge.
Constructions of Anderson’s Bridge
The bridge has fours arms ab, bc, cd, and ad.The
arm ab consists unknown inductance along with
the resistance. And the other three arms consist the
purely resistive arms connected in series with the circuit.
The static capacitor and the variable resistor are
connected in series and placed in parallel with
the cd arm. The voltage source is applied to the terminal
a and c.
Theory of Anderson Bridge
Let, L1 – unknown inductance having a resistance R1.
R2, R3, R4 – known non-inductive resistance
C4 – standard capacitor.
At balance Condition,
Now,
The other balance condition equation is expressed as
By substituting the value of Ic in the above equation we
get,
and
on equating the equation, we get
Equating the real and the imaginary part, we get
Advantages of Anderson Bridge
The following are the advantages of the Anderson’s
Bridge.
1. * The balance point is easily obtained on the Anderson
bridge as compared to Maxwell’s inductance capacitance
bridge.
2. * bridge uses fixed capacitor because of which accurate
reading is obtained.
3. * The bridge measures the accurate capacitances in
terms of inductances.
Disadvantages of Anderson Bridge
The main disadvantages of Anderson’s bridge are as
follow.
1. * The circuit has more arms which make it more
complex as compared to Maxwell’s bridge. The equation
of the bridge is also more complex.
2. * The bridge has an additional junction which arises the
difficulty in shielding the bridge.
