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

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Q. 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

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

Reason (R): Capacitors are mostly perfect.

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

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Q. The Lissajous pattern observed on screen of CRO is a straight line inclined at 45° to x axis. If X-plate input is 2 sin ωt, the Y-plate input is

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Q. The angle δ for a mica capacitor is about

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Q. 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

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Q. The coil of a moving coil meter has 100 turns, is 40 mm long and 30 mm wide. The control torque is 240 x 10¯⁶ N-m on full scale. If B = 1 Wb/m², range of meter is

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Q. 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

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