Q. Two resistances R1 = 18.7 Ω. and R2 = 3.624 Ω in series. The total resistance to the appropriate number of significant figures is

View solution

Q. The input impedance of CRO is about

View solution

Q. Which of the following is not correct in respect of electrostatic instrument?

View solution

Q. The wave applied to X plates, for ohtaining trace of voltage wave, is

View solution

Q. The response of a thermistor overs the whole of its temperatures range is

View solution

Q. A resistance is measured by voltmeter-ammeter method. The voltmeter is 0-250V, ± 1% accuracy and ammeter is 0-5 A, ± 1 % accuracy. The readings of voltmeter and ammeter are 100 V and 2 A respectively. The error in the measured resistance can be

View solution

Q. It is required to study transients during switching process. Which CRO should be preferred?

View solution

Q. Assertion (A): In loss of charge method, it is preferable to use an electronic voltmeter.

Reason (R): The resistance of electronic voltmeter is very high.

View solution

Q. If the secondary winding of CT is opened when primary coil is carrying current

View solution

Q. The percentage limiting error in an instrument reading 8.3 V and having guaranteed accuracy of 1% of the full scale reading and range of 0-150 V is

View solution

Q. Consider the following features of an instrument

I. suitable for both ac and dc
II. free from hysteresis and eddy current errors
III. No waveform and frequency errors
IV. it is essentially a voltmeter

This instrument is

View solution

Q. Which one of the following effects is used in measuring power?

View solution

Q. The effect of lead resistance is important in measurement of

View solution

Q. A high resistance was measured by loss of charge method. The voltmeter resistance was 10¹ᴼ ohms. The calculation gave the value of unknown resistance as 0.8 x 10⁹ ohms. The true value of resistance is

View solution

Q. A resistance wire strain gauge has gauge factor 2. If stress is 100 mega newton/m² and Young's modulus is 200 giga newton/ m², the percentage change in gauge resistance due to stress is

View solution

Q. The loss of charge method can be used to measure

View solution

Q. Assertion (A): Maxwell bridge is for measuring inductance of medium magnitude.

Reason (R): In Maxwell's bridge the unknown inductance is measured by comparing it with a capacitance.

View solution

Q. Assertion (A): A semiconductor strain gauge is more accurate than a resistance strain gauge.

Reason (R): The gauge factor of a semiconductor strain gauge is about 100 where as the gauge factor of a resistance strain gauge is only about 2.

View solution

Q. Current density has the dimensions

View solution

Q. The resistance of a dc galvanometer is 20 Ω. A current of 10 mA causes full scale deflection. To convert it into 0-300 V voltmeter, we have to use a series resistance of

View solution