Q. A standard cell of 1.0185 V is used with a slide wire potentiometer. The balance was obtained at 60 cm. When an unknown emf was connected, the balance was obtained at 82 cm. The magnitude of unknown emf is

View solution

Q. A dynamometer wattmeter is connected in ac circuit. The measured power is

View solution

Q. Loss of charge method is suitable for medium resistances.

View solution

Q. In two wattmeter method of 3 phase power measurement, when does one wattmeter read negative

View solution

Q. It is required to measure angular position. Out of the transducers

1.Circular potentiometer
2. LVDT
3. E pick up
4. Synchro

The proper devices are

View solution

Q. To increase Q factor of a coil, the wire should be

View solution

Q. An ammeter of 0-25 A range has a guaranteed accuracy of 1% of full scale reading. The current measured is 5 A. The limiting error is

View solution

Q. The coil of a moving iron instrument has a resistance of 500 Ω and an inductance of 1 H. It reads 250 V when a 250 V dc is applied. If series resistance is 2000 Ω, its reading when fed by 250 V, 50 Hz ac will be

View solution

Q. In 3 phase power measurement by two wattmeter method, the reading of one wattmeter is zero. The power factor of load is

View solution

Q. In a CRO which of the following is not a part of electron gun

View solution

Q. In a ballistic galvanometer, a charge of 100 μC gives a first swing of 25°. The charge required to cause first swing of 50° is

View solution

Q. Two resistors R1 = 36 Ω ± 5% and R2 = 75 Ω ± 5% are connected in series. The total resistance is

View solution

Q. In a strain measuring device using a strain gauge, the output quantity is

View solution

Q. A moving coil instrument has a resistance of 0.6 Ω and full scale deflection at 0.1 A. To convert it into an ammeter of 0-15 A range, the resistance of shunt should be

View solution

Q. A piezoelectric force transducer has a charge sensitivity of 20 pC/N. It is connected to a charge amplifier and overall gain of transducer and amplifier is 50 mV/N. The gain of amplifier is

View solution

Q. An LVDT is used to measure displacement. The LVDT feeds a Voltmeter of 0-5 V range through a 250 gain amplifier. For a displacement 0.5 mm the output of LVDT is 2 mV. The sensitivity of instrument is

View solution

Q. Assertion (A): When a wattmeter is used for low impedance loads, the pressure coil is connected across the load.

Reason (R): A wattmeter measures apparent power.

View solution

Q. As per BIS there are 6 accuracy classes of instruments.

View solution

Q. If reference sound pressure P₀ is 2 x 10¯⁵ N/m², a sound pressure of 90 dB is equal to

View solution

Q. Which of the following voltmeters would you use for measuring voltage across 20 kΩ resistance?

View solution