Q. A rectifier voltmeter using bridge rectifier and PMMC meter is calibrated to read rms value of sine wave. A triangular wave is applied to it and it reads 6.82 V. The rms value of triangular wave is

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Q. A radiation thermometer is suitable for temperatures

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Q. A sinusoidal signal is measured by CRO. The scale is set at 4 mV/cm. If vertical distance between positive and negative peaks is 6 cm, the peak value of ac signal is

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Q. Wheatstone bridge is suitable for low resistances.

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Q. To avoid creep in an energy meter

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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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