BEE Measurement and Instrumentation 3

Question 1

Which transducer converts displacement into a proportional electrical voltage using magnetic coupling?

Accepted Answer

LVDT

Answer

The Linear Variable Differential Transformer (LVDT) produces an AC output voltage proportional to the core's displacement from its null position.

Question 2

In a Wheatstone bridge, balance is achieved when:

Accepted Answer

P/Q = R/S

Answer

Bridge balance requires P/Q = R/S (or equivalently P×S = Q×R), producing zero galvanometer deflection.

Question 3

A thermocouple generates an EMF based on the:

Accepted Answer

Seebeck effect

Answer

The Seebeck effect causes a voltage to develop at the junction of two dissimilar metals when a temperature difference exists.

Question 4

Which of the following instruments is used to measure power in a three-phase, three-wire unbalanced load using only two wattmeters?

Accepted Answer

Two-wattmeter method

Answer

The two-wattmeter method correctly measures total three-phase power in any three-wire system regardless of load balance.

Question 5

Creep in an energy meter refers to:

Accepted Answer

Continuous rotation of the disc with no load applied

Answer

Creep is the slow continuous rotation of the energy meter disc when voltage is applied but no load current flows, causing measurement error.

BEE - Bachelor of Electrical Engineering Practice Test