Q. A wire strain gauge has a gauge factor of 2, resistance of 125 Ω and length 1 m. If length of wire changes by .005 m, change in resistance will be

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Q. Four voltmeters have following specifications. If accuracy is main consideration which is the best?

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Q. The deflection of a DArsonval galvanometer is measured through a mirror and scale. The mirror is 1 m away from the light source. The mirror is mounted on, the moving system. If mirror rotates through 0.2 rad the displacement on the scale is

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Q. Two ammeters having resistances of 0.5 Ω and 0.25 Ω and having full scale reading of 25 A each are connected in parallel. To ensure that neither of them goes beyond scale, the total current should not be more than

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Q. A polyphase wattmeter basically consists of two wattmeters. The moving system of two wattmeters

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Q. The dead zone in a pyrometer is 0.125% of span. The calibration is 400°C to 1000°C. What temperature change might occur before it is detected.

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Q. The dimensions of force are

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Q. A 1 mA meter is to be converted to 1 A ammeter. The meter resistance is 100 Ω. The value of shunt resistance is

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Q. The use of thermocouple meters for ac measurement leads to a scale which is

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Q. Assertion (A): A low power factor wattmeter has special constructional features to ensure accurate measurement.

Reason (R): Extension of wattmeter range in dc circuit can be easily done by using current and potential transformer.

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Q. The scale of dynamometer wattmeter is non linear.

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Q. Magnetic deflection is inversely proportional to

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Q. The current passing through a resistance of 100 ± 0.2% Ω is 2 ± 0.5% A. The limiting error in computation of power will be

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Q. If the secondary burden of a CT 15 VA and secondary current is 5 A, the load impedance of CT is

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Q. Consider the following instruments

1. Tangent galvanometer
2. Rayleigh current balance
3. Household energy meter
4. Hot wire ammeter

Out of above absolute instruments are

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Q. A 0-150 voltmeter has a guaranteed accuracy of 1% of full scale reading. If actual reading is 83 V, the percentage error is

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Q. In a CRO, the frequency of output of time base generator

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Q. If A = 131 ± 4 and B = 106 ± 4, the percentage range of doubt in A - B is

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Q. Two resistance R1 and R2 are connected in series R1 = 528 ± 5 Ω and R2 = 325 ± 3Ω. The total resistance will be

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Q. The function of shunt in an ammeter is to

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