Q. Consider the following operation in respect of Wheatstone bridge (Kb, denotes battery key, Kg denotes galvanometer key)

1. open Kb
2. close Kg
3. close Kb
4. open Kg

The correct sequence of operations is

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Q. Two voltmeters 0-250 V each having resistances of 5 kΩ and 10 kΩ respectively and are connected in series. To ensure that neither of them goes beyond scale the total voltage which can be applied should be less than

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Q. A 24 mm long conductor has a resistance of 128 Ω. The change in resistance is 13.3 Ω and change in length is 1.6 mm under tension. The gauge factor is

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Q. Measuring of unknown voltage with a dc potentiometer loses its advantage of open circuit measurement when

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Q. In a digital measuring device the input electrical signal is in the frequency range of dc to ac (50) Hz. It must be sampled at a rate of

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Q. The volt ratio box is basically a

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Q. A sinusoidal ac voltage of amplitude 100 V is applied to a rectifying device which offers 10 Ω resistance in forward direction and infinite resistance in backward direction. A moving coil ammeter is also connected in the circuit. The reading of ammeter will be

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Q. A variable reluctance tachometer has 180 teeth on rotor. The speed of shaft on which it is mounted in 1200 rpm. The frequency of output pulses is

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Q. Assertion (A): Wien bridge can be used for measuring frequency.

Reason (R): A frequency meter for 50 Hz system has a frequency range of 40 to 60 Hz.

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Q. Which of these has poor overload capacity?

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Q. In 3 phase power measurement by two wattmeter method, both wattmeters had equal reading. The power factor of load is

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Q. Which instrument is based on induction principle?

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Q. Magnetic field intensity has the dimensions

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Q. The power input and output in a device are 3650 W and 3385 W with each reading in doubt by ± 10 W. The percentage uncertainty in losses is

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Q. A meter coil has a resistance of 100 Ω and a full scale deflection current of 10 mA. To convert it into a voltmeter of 0-200 V range, the series resistance should be

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Q. Which of these has a magnetic brake?

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Q. Two numbers are 131 ± 5 and 629 ± 3. The sum of the numbers with range of doubt is

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Q. Assertion (A): Schering bridge is a low voltage bridge.

Reason (R): Schering bridge is very commonly used for measurement of capacitance.

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Q. Electrostatic voltmeter is suitable only for low voltages.

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Q. 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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