Q. The household energy meter is

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Q. 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

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Q. A dynamometer wattmeter is connected in ac circuit. The measured power is

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Q. Loss of charge method is suitable for medium resistances.

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Q. In two wattmeter method of 3 phase power measurement, when does one wattmeter read negative

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Q. It is required to measure angular position. Out of the transducers

1.Circular potentiometer
2. LVDT
3. E pick up
4. Synchro

The proper devices are

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

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Q. 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

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Q. 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

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

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

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Q. 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

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Q. Two resistors R1 = 36 Ω ± 5% and R2 = 75 Ω ± 5% are connected in series. The total resistance is

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

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Q. 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

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Q. 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

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Q. 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

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Q. 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.

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Q. As per BIS there are 6 accuracy classes of instruments.

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Q. If reference sound pressure P₀ is 2 x 10¯⁵ N/m², a sound pressure of 90 dB is equal to

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