MEASUREMENT AND INSTRUMENTATION QUIZ

A single phase load is connected between R and Y terminals of a 415 V, symmetrical, 3-phase, 4 wire system with phase sequence RYB. A wattmeter is connected in the system as shown in figure. The power factor of the load is 0.8 lagging. The wattmeter will read

- 795 W.

+ 597 W.

- 597 W.

+ 795 W.

TRUE ANSWER : ?
YOUR ANSWER : ?

The limiting errors of measurement of power consumed by and the current passing through a resistance are ±1.5% and ±1% respectively. What is the limiting error ( in %) of measurement of resistance ?

± 1.5%

± 2.5%

±3.5%

± 1%

TRUE ANSWER : ?
YOUR ANSWER : ?

An average reading digital multimeter reads 10 V when fed a triangular wave, symmetric about the axis. For the same input, an rms reading meter will read

10√3.

10.

20√3.

20.

TRUE ANSWER : ?
YOUR ANSWER : ?

The current coil of a wattmeter is connected to the CT of R-phase. The potential coil is connected across Y and B phases. The wattmeter measures

Active power in R phase

Reactive power of R phase

Power proportional to 3 phase power if the load is balanced

Active power of Y phase

TRUE ANSWER : ?
YOUR ANSWER : ?

The pointer of an indicating instrument should be

Either light or heavy

Very light

None of the listed here

Very heavy

TRUE ANSWER : ?
YOUR ANSWER : ?

Which one of the following meters has maximum loading effect on the circuit under measurement ?

1000 Ω/volt

10 MΩ/volt

100 Ω/volt

1 MΩ/volt

TRUE ANSWER : ?
YOUR ANSWER : ?

The difference between the measured value and the true value is called

absolute error

relative error

gross error

probable error

TRUE ANSWER : ?
YOUR ANSWER : ?

To measure the flux, devices used are based on

Piezo-electric effect

Hall effect

Photo-voltaic effect

Voltaic effect

TRUE ANSWER : ?
YOUR ANSWER : ?

An ammeter is a

Absolute instrument

Secondary instrument

Integrating instrument

Recording instrument

TRUE ANSWER : ?
YOUR ANSWER : ?

Relative error is same as

true error.

None of these

ratio of absolute error and true value.

absolute error.

TRUE ANSWER : ?
YOUR ANSWER : ?

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