1. How are the inter-capacitance errors minimized?
a) by separating the plates of the capacitance
b) by using earthing
c) by reducing the area of cross section of the capacitors
d) by increasing the distance between the capacitor plates
Explanation: In a high voltage Schering bridge, errors due to inter-capacitance between the high and low impedance ratio arms can be eliminated through earthing screens.
2. How to minimize the effect of earth capacitance?
a) by increasing the supply voltage
b) by using a series resistance
c) by using a Wagner ground connection
d) by using an inductor across the circuit
Explanation:In a high voltage Schering bridge, the effect of earth capacitance on the circuit including the galvanometer and the contact leads is minimized by making use of a Wagner ground connection.
3. What is the effect of breakdown of high voltage capacitor?
a) No effect
b) voltage drop across the circuit reduces
c) circuit components rupture
d) a high voltage appears across the branches
Explanation:In a high voltage Schering bridge, a very high voltage appears across the branches when the breakdown of high voltage capacitor occurs. This is prevented by making use of a spark gap across the branches involved.
4. What is the dependence of frequency on the balance equation?
a) independent
b) varies by a factor of 2
c) depends on the supply magnitude
d) depends on the detector used
Explanation:In a high voltage Schering bridge, the balance equation does not depend on the frequency of operation of the circuit. A detector is only used for detecting the balance condition in a bridge circuit
5.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
Explanation: 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.
6. Balance equation for computing the unknown resistance is?
a) Rx = \(\frac{R_2}{R_1}\)
b) Rx = \(\frac{R_2 R_3}{R_1}\)
c) Rx = \(\frac{R_3}{R_1}\)
d) Rx = \(\frac{1}{R_1}\)
Explanation: The balance condition for determining the value of the unknown resistance is given by the relation Rx = \(\frac{R_2 R_3}{R_1}\)
where, R1 and R3 are variable resistances and R2 is a fixed resistance.
7. Balance equation for computing the value of the unknown inductance is?
a) Lx = R2 R3
b) Lx = R2 C1
c) Lx = R2 R3 C1
d) Lx = R3 C1
Explanation: The balance equation for determining the value of the unknown inductance is given by the relation Lx= R2 R3 C1.
where,
C1 is the capacitance across the resistance R1
R3 is a variable resistance and R2 is a fixed resistance.
8. Quality factor of the circuit is given by _________
a) Q = ωC1
b) Q = ωR1
c) Q = ω
d) Q = ωR1 C1
Explanation: The quality factor of a Maxwell inductance capacitance bridge is given by the relation
9. Standard inductor requires no shielding.
a) True
b) False
Explanation: 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
10. Standard inductor provides rated inductance directly.
a) True
b) False
Explanation: When the current flow through the standard inductance is adjusted precisely, it provides its rated value of inductance.