Question

Match the following Instruments given in column 1 with respective quantities they read in column 2.

Column 1	Column 2
1. De’sauty Bridge	a. Capacitance
2. Potentiometer	b. Low Resistance
3. Megger	c. High Resistance
4. Wattmeter	d. Power

1. 1 - a, 2 - c, 3 - b, 4 - d
2. 1 - d, 2 - c, 3 - b, 4 - a
3. 1 - d, 2 - b, 3 - c, 4 - a
4. 1 - a, 2 - b, 3 - c, 4 - d

Answer 1

Correct Answer - Option 4 : 1 - a, 2 - b, 3 - c, 4 - d

Bridges and their Applications:

Type of Bridge	Name of Bridge	Used to measure	Important
DC Bridges	Wheatstone bridge	Medium resistance
	Corey foster’s bridge	Medium resistance
	Kelvin double bridge	Very low resistance
	Loss of charge method	High resistance
	Megger	High insulation resistance	Resistance of cables
AC Bridges	Maxwell’s inductance bridge	Inductance	Not suitable to measure Q
	Maxwell’s inductance capacitance bridge	Inductance	Suitable for medium Q coil (1 < Q < 10)
	Hay’s bridge	Inductance	Suitable for high Q coil (Q > 10), slowest bridge
	Anderson’s bridge	Inductance	5-point bridge, accurate and fastest bridge (Q < 1)
	Owen’s bridge	Inductance	Used for measuring low Q coils
	Heaviside mutual inductance bridge	Mutual inductance
	Campbell’s modification of Heaviside bridge	Mutual inductance
	De-Sauty’s bridge	Capacitance	Suitable for perfect capacitor
	Schering bridge	Capacitance	Used to measure relative permittivity
	Wein’s bridge	Capacitance and frequency	Harmonic distortion analyzer, used as a notch filter, used in audio and high-frequency applications

 

Wattmeter:

A wattmeter is an electrical instrument that is used to measure the electric power of any electrical circuit.

The internal construction of a wattmeter is such that it consists of two coils. One of the coils is in series and the other is connected in parallel.

The coil that is connected in series with the circuit is known as the current coil and the one that is connected in parallel with the circuit is known as the voltage coil

Wattmeter measures the average power.

Potentiometer Method:

• It works by comparing the unknown resistance with the standard resistance.
• The voltage drop across the known and unknown resistance is measured and by comparison the value of known resistance is determined.
• The potentiometer can be used to measure low resistance.