# Measurement and Instrumentation

Measurement and Instrumentation
Question:-
Option (A)
1, 2 and 3
Option (B)
1, 3 and 4
Option (C)
1 and 3
Option (D)
1 and 4
Correct Option:
D
Question Solution:
. Digital data acquisition systems can be used with analog output as well as digital output of the transducers. Analog data can be converted into digital through A/D converter
. Refer TDM; when telemetering slow changing, low band with data, it would be extremely wasteful if these measurements occupied a full RF communication link. To increase efficiency, the communication link should be used for other measurements during the “data” interval between samples. We see that efficient use of the communication system may be achieved by time-sharing the communication channel among a number of measured parameters
. Further, Digital data acquisition system are highly accurate due to better noise immunity
Question:-
Option (A)
The plot between Q and frequency is linear
Option (B)
The value of Q initially decrease with increase of frequency and afterwards it will increase with increase of frequency
Option (C)
The value of Q initially increases with increase of frequency and afterward it will decrease with increase of frequency
Option (D)
The Q-factor remains constant irrespective of value of frequency
Correct Option:
C
Question:-
Option (A)
A B C D
4 3 2 1

Option (B)
A B C D
4 1 2 3

Option (C)
A B C D
2 1 4 3

Option (D)
A B C D
2 3 4 1

Correct Option:
D
Question Solution:
. The Wien’s bridge is primarily known as a frequency determining bridge. It may be employed in a harmonic distortion analyzer, where it is used as notch filter, discriminating against one specific frequency. The Wien’s bridge also finds applications in audio and HF oscillators as the frequency determining device
The Hay’s bridge is suited for the measurement of high Q inductors especially those inductors having a greater then 10. For inductors having Q greater then 10. For inductors having Q values smaller then 10, the term (1/Q)2 in the expression for inductance
L1 = {R2R3C4} / {1+(1/Q)2}
Becomes rather important and thus cannot be neglected. Hence this bridge is not suited for measurements of coils having Q less then 10 and for these applications a Maxwell’s bridge is more suited
Question:-
Option (A)
A second defined as 1/86, 400 of a mean solar day
Option (B)
A second defined as time constant of an RC series circuit having R=2 M ohm C = 50 pF
Option (C)
A second which is duration of 9192631770 periods of radiation corresponding to the transition between the two hyperfine levels of the fundamental state of the atom cesium 133
Option (D)
A second defined as 1/31556925.9747 of the time required by the earth to orbit the sum in the year 1990
Correct Option:
C