ETC ETC Electrical Systems & Instrumentation

Question 1

What does the term 'voltage drop' refer to in an electrical circuit?

Accepted Answer

Reduction in voltage across a component due to resistance

Answer

Increase in current through a resistor

Answer

Loss of frequency in an AC circuit

Answer

Drop in power factor below unity

Question 2

Which instrument is used to measure electrical resistance in a circuit?

Accepted Answer

Ohmmeter

Answer

Voltmeter

Answer

Ammeter

Answer

Wattmeter

Question 3

What is the purpose of a circuit breaker in an electrical panel?

Accepted Answer

To protect wiring from overcurrent by interrupting the circuit

Answer

To increase voltage supply

Answer

To reduce power factor

Answer

To step up transformer output

Question 4

In a three-phase power system, what is the phase angle difference between each phase?

Accepted Answer

120 degrees

Answer

90 degrees

Answer

45 degrees

Answer

180 degrees

Question 5

Which type of sensor converts physical displacement into an electrical signal?

Accepted Answer

LVDT (Linear Variable Differential Transformer)

Answer

Thermocouple

Answer

Pitot tube

Answer

Bourdon gauge

Question 6

What does a 4-20 mA signal represent in industrial instrumentation?

Accepted Answer

A standard analog current loop used to transmit process variable data

Answer

A digital binary signal for on/off control

Answer

A high-voltage DC signal for motor drives

Answer

A frequency modulated signal for PLCs