Instrumentation Transducers

Performance of Systems

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the given factor determines the order of a system?
Maximum power of ‘S’ in the characteristic equation
Minimum power of ‘S’ in the characteristic equation
Value of constant value
None of the mentioned
Explanation:
Maximum power of ‘S’ in the characteristic equation is known as an order of that system. For a zero-order system, power of ‘S’ will be zero and for first-order system maximum power of ‘S’ will be one.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of the following represent condition for an over-damped system?
Damping ratio<0
Damping ratio=0
Damping ratio=0.5
Damping ratio>1
Explanation:
A system with damping ratio ξ greater than 1 is said to be over damped system.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
For a ramp input in second order system, which of the following represents the correct relationship between natural frequency and steady state error?
Both are directly proportional
Both are inversely proportional
Both are equal
None of the mentioned
Explanation:
Steady state error for second order system with ramp input can be represented as 2ξK/ωn, where ωn represents natural frequency.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Transfer function of a system is given by G(S) = b0 ⁄ a1S+a0. What will be the static sensitivity of system?
b0 ⁄ a0
b0 ⁄ a1
a0 ⁄ b0
a1 ⁄ b0
Explanation:
Transfer function can be converted into G(S) = K ⁄ (Ï„S+1), in which K is known as static sesistivity of system. Thus K can be expressed as a ratio of b0 and a0.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Transfer function of a system with input y(t) = t2/2 is given by 1/S. What will be the obtained output?
6t3
t3/6
t3
t4
Explanation:
Transfer function of a system is the ratio of output and input of the system in S domain.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which of the following represents a system with transfer function G(S) = 5/(3S2+8S+3) ?
Over damped system
Un-damped system
Under damped system
None of the mentioned
Explanation:
Damping ratio of a second order system can be found using equation a1/(2√a0a2) which is equal to 1.33. For a damping ratio greater than 1, system will be over damped system.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Which of the given statement is true for a zero-order system?
Varying transfer function with time
Constant transfer function
Transfer function = 1/S
Transfer function = 1/s2
Explanation:
Order of a system is the maximum power of ‘S’ in the characteristic equation. For a zero-order system, S will have a power zero and Transfer function will be a constant value.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What will be the time constant for a system represented by transfer function G(S) = 5/(3S+2)?
3
2.5
1.5
2
Explanation:
Transfer function can be represented as G(S) = K/(Ï„S+1), in which time Ï„ represents time constant.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
What will be the static sensitivity of a system with transfer function G(S) = 4/(5S2+8S+2)?
0.5
2
4
4/5
Explanation:
Static sensitivity of a system with transfer function G(S) = b0/(a2S2+a1S+a0) can be represented as b0/a0.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
What will be the damping ratio of a system with transfer function G(S) = 5/(3S2+2S+3)?
1.5
0.5
0.33
2
Explanation:
Damping ratio of a system with transfer function G(S) = b0 ⁄ (a2S2+a1S+a0), can be found using equation a1 ⁄ (2√ a0a2). Damping ratio of given system will obtain as 0.333.