Electrical Measurements & Measuring Instruments Multiple Choice Questions on “Maxwell’s Inductance Capacitance Bridge”.

1. Maxwell inductance capacitance bridge can be used for _________

a) measurement of inductance

b) measurement of capacitance and inductance

c) measurement of resistance

d) measurement of voltage and current

Answer: a

Clarification: A Maxwell inductance capacitance bridge is used for the measurement of inductance by making comparison with a standard capacitance value. Voltmeter is used to measure voltage, while an ammeter is used to measure current.

2. Balance equation for computing the unknown resistance is?

a) R_{x} = (frac{R_2}{R_1})

b) R_{x} = (frac{R_2 R_3}{R_1})

c) R_{x} = (frac{R_3}{R_1})

d) R_{x} = (frac{1}{R_1})

Answer: b

Clarification: The balance condition for determining the value of the unknown resistance is given by the relation R_{x} = (frac{R_2 R_3}{R_1})

where, R_{1} and R_{3} are variable resistances and R_{2} is a fixed resistance.

3. Balance equation for computing the value of the unknown inductance is?

a) L_{x} = R_{2} R_{3}

b) L_{x} = R_{2} C_{1}

c) L_{x} = R_{2} R_{3} C_{1}

d) L_{x} = R_{3} C_{1}

Answer: c

Clarification: The balance equation for determining the value of the unknown inductance is given by the relation L_{x}= R_{2} R_{3} C_{1}.

where,

C_{1} is the capacitance across the resistance R_{1}

R_{3} is a variable resistance and R_{2} is a fixed resistance.

4. Quality factor of the circuit is given by _________

a) Q = ωC_{1}

b) Q = ωR_{1}

c) Q = ω

d) Q = ωR_{1} C_{1}

Answer: d

Clarification: The quality factor of a Maxwell inductance capacitance bridge is given by the relation

5. Standard inductor requires no shielding.

a) True

b) False

Answer: b

Clarification: Stray magnetic fields are present in a circuit consisting of inductances and capacitances. In order to eliminate the stray magnetic fields proper shielding is required for the standard inductance.

6. Standard inductor provides rated inductance directly.

a) True

b) False

Answer: b

Clarification: When the current flow through the standard inductance is adjusted precisely, it provides its rated value of inductance.

7. What is the significance of capacitors in a Maxwell bridge?

a) they are used to block dc

b) they are used to block ac

c) they are cheap

d) they are expensive

Answer: c

Clarification: In a Maxwell inductance capacitance bridge, the capacitors are cheaper when compared to a stable and accurate standard value of inductors.

8. The bridge balance equation can be written in _________

a) impedance form

b) resistance form

c) conductance form

d) admittance form

Answer: d

Clarification: The bridge balance equation for a Maxwell inductance capacitance bridge consists of admittances. This is due to the connection of capacitance in parallel across the resistance in one of the ratio arms.

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