ECE :: Measurements and Instrumentation
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Kelvin's double bridge is used to measure low resistances because
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Assertion (A): Shunt of an ammeter has a low resistance.
Reason (R): Shunt may be connected in series or in parallel with ammeter.
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The D'Arsonval- movement can be converted into audio frequency ac ammeter by adding a
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The resistance of a 125 Ω strain gauge changes by 1 ohm for 4000 micro strain. The gauge factor is
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An accelerometer has a seismic mass of 0.05 kg and spring constant of 3 x 105 N/m. If maximum displacement of mass is ± 1 mm, the maximum acceleration which can be measured is
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If an inductance L is connected in one arm of bridge and resistance R1, R2, R3 in other three arms
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A moving iron voltmeter reads 250 V when connected to 250 V dc. If connected to 250 V 50 Hz, the voltmeter reading is likely to be
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A single element strain gauge bridge has two fixed resistances R1 and R1 of 120 Ω each and a variable resistance which gives full deflection at 120 Ω for zero strain and 120.6 Ω for straine e. If gauge factor is 2, strain e is