01․ The total current I = I1 + I2 in a circuit is measured I1 = 150 ± 3A , I2 = 250 ± 4 A, where the limits of error are given as standard deviations. I is measured as
02․ A first order instrument is characterized by
A first order system can be represented as Where, T is time constant.
03․ The ratio of change in output to the change in the input is called
Sensitivity indicates how promptly an instrument can sense any change in input signal. The ratio of change in output to the change in the input is called sensitivity.
04․ The difference between the indicated value and the true value of a quantity is
The difference between the indicated value and the true value or actual value of a quantity is called absolute error.
05․ Which one the following statements is correct? The application of the instrument in wrong manner in the procedure of measurement results in a/an
The application of the instrument in wrong manner in the procedure of measurement results in an instrument error. As this error is resulted from instrument itself.
06․ Two capacitance, C1 = 150 ± 2.4µF and C2 = 120 ± 1.5 µF are connected in parallel. What is the limiting error of the resultant capacitance C (in µF) ?
Equivalent capacitance of the given parallel combination is C = C1 + C2. So, limiting error of C is (2.4 + 1.5) = 3.9 µF
07․ Dynamic errors are caused by
Dynamic errors are caused due to sluggish response of instrument.
08․ If two 300V full scale voltmeters V1 and V2 having sensitivities of 100 kOhm/V and 150 kOhm/V are connected in series to measure 500V then
The reading of voltmeters will be given as Reading of V1/ Reading of V2 = Sensitivity of V1/ Sensitivity of V2.
09․ A 0 - 200 V voltmeter has a guaranteed accuracy of 1% of full scale reading. The voltage measured by this instrument is 50 V. What is the limiting error?
10․ The three resistors R1, R2 and R3 have the following ratings: R1 = 25Ω ± 4%, R2 = 65 Ω ± 4%; R3 =45 Ω ± 4%. If the resistance are connected in series, then limiting error produced in equivalent resistance is
As limiting error of each resistance is ± 4% the limiting error of series combination of all resistance will also be ± 4%