250+ TOP MCQs on Bridge Balance Equation and Answers

Electrical Measurements & Measuring Instruments Multiple Choice Questions on “Bridge Balance Equation”.

1. Bridge balance equation for magnitude is given by which of the following relation?
a) Z₁ Z₄ = Z₂ Z₃
b) Z₁ Z₂ = Z₃ Z₄
c) Z₂ Z₄ = Z₁ Z₃
d) Z₁ Z₃ = Z₂ Z₄
Answer: a
Clarification: In an AC bridge, the balance condition for magnitude is given by the equation
Z₁ Z₄ = Z₂ Z₃
where, Z₁, Z₂, Z₃ and Z₄ are the impedance arms of the AC bridge circuit.

2. Angular balance equation is given by which of the following relation?
a) θ₁ × θ₄ = θ₂ × θ₃
b) θ₁ + θ₄ = θ₂ + θ₃
c) θ₂ + θ₄ = θ₁ + θ₃
d) θ₂ × θ₄ = θ₁ × θ₃
Answer: b
Clarification: The angular balance condition in an AC bridge is given by the relation
θ₁ + θ₄ = θ₂ + θ₃
Where,
θ₁, θ₂, θ₃ and θ₄ are the phase angles of the impedances Z₁, Z₂, Z₃ and Z₄.

3. Bridge must be balanced for ________
a) magnitude
b) angle
c) magnitude and angle
d) power
Answer: c
Clarification: The ratio arms consist of impedances which have magnitude as well as phase. In an AC bridge, balance condition implies magnitude balance as well as angular balance.

4. Phase angle is based on _______
a) source
b) detector
c) power
d) impedance
Answer: d
Clarification: The four ratio arms comprise of impedances which consist of not only magnitude but some phase as well. Value of the phase angles are based on the component of individual impedances.

5. For inductive impedances, the phase angle is _______
a) positive
b) negative
c) zero
d) exponential
Answer: a
Clarification: The current through an inductor does not increase instantaneously. For inductive impedances, the voltage leads the current and as a result the phase angle is positive.

6. For capacitive impedances, the phase angle is _______
a) tangential
b) negative
c) positive
d) logarithmic
Answer: b
Clarification: The voltage across a capacitor does not rise instantaneously. For capacitive impedances, the current leads the voltage and as a result the phase angle is negative.

7. Bridge balance equation for magnitude in terms of admittances is given by the relation.
a) Y₁Y₃ = Y₂Y₄
b) Y₁Y₂ = Y₃Y₄
c)Y₁Y₄ = Y₂Y₃
d) Y₁ Y₃ = Y₂ Y₄
Answer: c
Clarification: Admittance is the reciprocal of impedance. The balance condition for magnitude is given by the equation