Correct Answer - Option 4 : ± 1 percent
Concept:
Limiting Error:
The maximum allowable error in the measurement is specified in terms of true value, which is known as limiting error.
It will give a range of errors. It is always with respect to the true value, so it is a variable error.
1) If two quantities are getting added, then their limiting errors also gets added.
2) If two quantities are getting multiplied or divided, then their percentage limiting errors get added.
Calculation:
The ammeter reads 0A to 200 mA
GAE of Ammeter = ± 0.5 %
Error in voltmeter measurement on FSD = 0.005 × 200 = 1 A
Percentage error at 100 mA
Limiting error \( = \frac{{1}}{100} \times 100 = 1.0\% \)
Therefore the percentage limiting error at 100 mA is ± 1 percent
Note:
Absolute Error: The deviation of the measured value from the true value (or) actual value is called error.
Absolute error (E) = Am – At
Am = Measured value
At = True value
Relative Static Error: The ratio of absolute error to the true value is called relative static error.
\(R.S.E = \frac{{\left| {{A_m} - {A_t}} \right|}}{{{A_t}}} \times 100\)
Guaranteed Accuracy Error: The allowable error in measurement is specified in terms of full-scale value is known as a guaranteed accuracy error. It is a constant error seen by the instrument since it is with respect to full-scale value.
