Question

Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured?

• A. Absolute instruments
• B. Indicating instruments
• C. Recording instruments
• D. Integrating instruments

Hint:

Remember the key distinction:
Indicating = Shows instantaneous value (e.g., Voltmeter).
Recording = Keeps a continuous record over time (e.g., ECG recorder).
Integrating = Accumulates/sums up over time (e.g., Energy meter).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks us to identify the class of electrical measuring instruments that displays the real-time, instantaneous value of a parameter at the exact moment of observation.

Step 2: Detailed Explanation:

• Measuring instruments in electrical engineering are broadly classified into four major categories based on their operation:

• Absolute Instruments: These instruments give the value of the quantity to be measured in terms of the physical constants of the instrument (e.g., Tangent Galvanometer). They do not require prior calibration.

• Indicating Instruments: These instruments indicate the instantaneous value of the electrical quantity being measured at the time of observation. They utilize a dial and a pointer system (e.g., ordinary ammeters, voltmeters, and wattmeters).

• Recording Instruments: These instruments continuously record the variations of the measured quantity over a specific period on a chart, paper, or digital database (e.g., strip-chart recorders).

• Integrating Instruments: These instruments measure and register the total quantity of electricity or energy consumed over a period of time (e.g., household energy meters/watt-hour meters).

• Since the question specifies the indication of the instantaneous value at the time of measurement, indicating instruments are the correct choice.

Step 3: Final Answer:
The instruments that indicate the instantaneous value of the measured quantity are indicating instruments.