EC Engineering Measurements and Instrumentation Online Test

To increase Q factor of a coil, the wire should be

An ammeter of 0-25 A range has a guaranteed accuracy of 1% of full scale reading. The current measured is 5 A. The limiting error is

The coil of a moving iron instrument has a resistance of 500 Ω and an inductance of 1 H. It reads 250 V when a 250 V dc is applied. If series resistance is 2000 Ω, its reading when fed by 250 V, 50 Hz ac will be

In 3 phase power measurement by two wattmeter method, the reading of one wattmeter is zero. The power factor of load is

In a CRO which of the following is not a part of electron gun

Which of the following voltmeters would you use for measuring voltage across 20 kΩ resistance?

A single phase energy meter has the rating 1200 resolutions/ kWh. If a 500 W electric gadget is used for 4 hours, the energy meter will make

Assertion (A): De sauty’s bridge is suitable only for pure capacitor.

Reason (R): Capacitors are mostly perfect.

In which of the transformer is the secondary nearly short circuited under normal operating conditions?

A moving coil instrument has a resistance of 0.6 Ω and full scale deflection at 0.1 A. To convert it into an ammeter of 0-15 A range, the resistance of shunt should be

A piezoelectric force transducer has a charge sensitivity of 20 pC/N. It is connected to a charge amplifier and overall gain of transducer and amplifier is 50 mV/N. The gain of amplifier is

An LVDT is used to measure displacement. The LVDT feeds a Voltmeter of 0-5 V range through a 250 gain amplifier. For a displacement 0.5 mm the output of LVDT is 2 mV. The sensitivity of instrument is

Assertion (A): When a wattmeter is used for low impedance loads, the pressure coil is connected across the load.

Reason (R): A wattmeter measures apparent power.

As per BIS there are 6 accuracy classes of instruments.

In a ballistic galvanometer, a charge of 100 μC gives a first swing of 25°. The charge required to cause first swing of 50° is

In a strain measuring device using a strain gauge, the output quantity is

The angle δ for a mica capacitor is about

A digital voltmeter has a read out range from 0 to 999 counts. If the full scale reading is 9.999 V, the resolution is

Consider the following statements: In a differential amplifier using JFET, the differential output offset is due to
1.mismatch between FET parameters
2.difference in values of resistances used in circuit
3.variation in supply voltage.
Of the statements, the correct statements are

A meter with a resistance of 100 Ω and a full scale deflection of current of 1 mA is to be converted into voltmeter of 0 – 5 V range. The multiplier resistance should be

The household energy meter is

A standard cell of 1.0185 V is used with a slide wire potentiometer. The balance was obtained at 60 cm. When an unknown emf was connected, the balance was obtained at 82 cm. The magnitude of unknown emf is

A moving coil instrument has a resistance of 0.5 Ω and a full scale deflection of 0.1 A. To convert it into an ammeter of 0-10 A the shunt resistance should be

Potentiometer method of dc voltage measurement is more accurate than direct measurement using a voltmeter because

Assertion (A): A hot wire ammeter has a cramped scale.

Reason (R): The heat is proportional to square of current.

Which of the following is true about an impulse voltage?

Which of the following are needed both for protection and metering?

A digital frequency counter can be converted to DVM by addition of a suitable

A dynamometer wattmeter is connected in ac circuit. The reading will be

The speed transducer using a drag cup rotor has the main advantage of