Question

In the Owen’s bridge shown in below figure, Z1 = 200∠60°, Z2 = 400∠-90°, Z3 = 300∠0°, Z4 = 400∠30°. Then the _______

(a) Bridge is balanced with given impedance values

(b) Bridge can be balanced, if Z4 = 600∠60°

(c) Bridge can be balanced, if Z3 = 400∠0°

(d) Bridge cannot be balanced with the given configuration

This question was addressed to me in an internship interview.

Enquiry is from Advanced Problems on Measurement of Inductance using AC Bridges in portion Measurement of Inductance and Capacitance of Electrical Measurements

Answer 1

Right answer is (d) Bridge cannot be balanced with the given configuration

For explanation: For Bridge to be balanced, the product of impedances of the opposite arm should be equal in magnitude as well as phase angle. Here Z3 Z2 ≠ Z1 Z4 for whatever chosen value. Therefore the Bridge cannot be balanced.