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

View solution

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

View solution

Q. The volt ratio box is basically a

View solution

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

View solution

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

View solution

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.

View solution

Q. Which of these has poor overload capacity?

View solution

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

View solution

Q. Which instrument is based on induction principle?

View solution

Q. Magnetic field intensity has the dimensions

View solution

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

View solution

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

View solution

Q. Which of these has a magnetic brake?

View solution

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

View solution

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

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

View solution

Q. Electrostatic voltmeter is suitable only for low voltages.

View solution

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

View solution

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

View solution

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

View solution

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

View solution