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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Q. If an inductance L is connected in one arm of bridge and resistance R1, R2, R3 in other three arms

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Q. 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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Q. 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

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Q. If eddy current damping is to be used, the disc of instrument should be

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Q. The scale of moving iron instrument is linear.

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Q. With a variable reluctance tachometer having 60 rotor teeth the count reads 3600 counts per minute. The speed in RPM is

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