Measuring Resistance the Wheatstone Bridge and Delta-to-Wye (Pi-to-Tee) Equivalent Circuits MCQ’s

This set of Electric Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Measuring Resistance the Wheatstone Bridge and Delta-to-Wye (Pi-to-Tee) Equivalent Circuits”.

1. The relation between the resistances in the given Wheatstone bridge circuit is _____________


a) P/S = R/Q
b) PR = QS
c) P/Q = R/S
d) PQ = RS

2. Find the unknown resistance value in given circuit.


a) 10.2Ω
b) 11.7Ω
c) 10.5Ω
d) 11.5Ω

3. The Wheatstone Bridge is mainly used to measure ______________
a) Currents
b) Voltages
c) Node potentials
d) Resistances

4. Lower resistances are difficult to measure using Wheatstone bridge circuit because of ____________
a) Leakage currents
b) I2R effects
c) Power dissipation
d) Thermal breakdown

5. The other name for Delta connection is ___________
a) Star connection
b) Pi connection
c) T connection
d) Y connection

6. If R2 = RC RA / (RA +RB +RC ) then R3 equals?
a) RA RB / (RA +RB +RC )
b) RC RA / (RA +RB +RC )
c) RB RC / (RA +RB +RC )
d) RX RA / (RA +RB +RC )

7. If P/Q=1, unknown resistance S=1000Ω and R could be varied from 0 to 100Ω then the bridge could be ___________
a) A balanced circuit
b) A rectified circuit
c) An unbalanced circuit
d) An identical circuit

8. Star connection can also be called as Y (or) T connection.
a) True
b) False

9. Convert the given Delta circuit to star circuit and give the Ra , Rb and Rc values.


a) Ra=5Ω, Rb = 4.5Ω, Rc=4.67Ω
b) Ra=4Ω, Rb=4.30Ω, Rc=4.66Ω
c) Ra=3Ω, Rb=4Ω, Rc =5Ω
d) Ra=5.2Ω, Rb=4.2Ω, Rc =4.89Ω

10. Convert the given star network into Pi network and calculate the sum of all the resistances in the obtained Pi network.


a) 125.5Ω
b) 122.5Ω
c) 127.8Ω
d) 129.8Ω

11. A Wheatstone bridge is balanced when the galvanometer shows __________ reading.
a) 0A
b) 1A
c) Infinity
d) -1A

12. Find VAB if iAB = 5A.


a) 32.76V
b) 35.56V
c) 36.12V
d) 34.21V

13. The star and delta networks would be electrically equal if resistances measured between any pair of terminals __________
a) Is different
b) Greater in star
c) Greater in delta
d) Is equal

14. __________ are difficult to measure using Wheatstone bridge.
a) Higher resistances
b) Currents
c) Lower resistances
d) Voltages

15. What will be the resistance between B and C when the network given below is converted into delta?


a) 13Ω
b) 8.66Ω
c) 6.5Ω
d) 7.33Ω

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