3. Other therapeutic approaches for depression
3.2. Interventions focused on positive affect
1. If a body has identical properties all over, it is known as A. Elastic.
B. Homogeneous.
C. Isotropic.
D. none of them.
"Homogeneous" is having all parts the same or similar in type.
2. A function of one or more variable which conveys information one to nature of physical phenomenon is called
. signal.
A. interference.
B. system.
C. noise.
Signal is also defined as any physical quantity that varies with time, space or any other independent variable.
3. The dc gain of a system represented by the transfer function 12 ⁄ (s+1)(s+3) is . 1.
A. 2.
B. 5.
C. 10.
d.c. gain T(s) at s = 0 , 12 ⁄ (0+2)X(0+3) = 12 ⁄ 6 = 2.
4. The transfer function of a system given by − 100/(s2 + 20s+100) the system is . an over damped.
A. a critically damped.
B. an under damped.
C. a unstable.
M(s) = Wn2/(s2 + 2ζWns + Wn2), 2ζWn + 20. So Wn = 1, here Wn = under damped natural frequency. ζ = damping ratio. If ζ = 1, it is critically damped system.
5. G(s) = ( s + 6 ) / s( s – 2 )( s – 4 ). Find the order of a system.
. 2.
A. 3.
B. 4.
C. 5.
Generally order of the system can be given by denominator of transfer function. The highest power of S is 3 in the denominator of transfer function.
6. G(s) = ( s + 4 ) / s2( s + 2 )( s + 4 ). Find the type of the system.
. 2.
A. 3.
B. 4.
C. 1.
Type of the system the no. of poles located at the origin. Here the no of pole at origin = 2.
7. A negative feedback closed loop system is supplied to an input of 5 volt. The system has a forward gain of 1& a feedback gain of 1.What is the output voltage
. 1.0 Volt.
A. 1.5 Volt.
B. 2.5 Volt.
C. 2.0 Volt.
We know that negative feedback closed loop system C(s)/R(s) = output/input = G(s)/{1 + G(s)H(s)}
G(s)=Forward gain, H(s)=Feedback gain. C(s) = R(s)G(s)/{1+G(s)H(s)} = 5X1/(1 + 1X1 ) = 2.5 Volt.
8. A system of constant voltage and constant frequency is called --- system.
. feedback.
A. infinite.
B. zero.
C. none of the above.
A system of constant voltage and constant frequency regardless of load is called infinite bus bar system.
9. None of the poles of a linear control system lie in the right half of s plane . For a bounded input, the output of this system
. always bounded.
A. could be unbounded.
B. tends to zero.
C. none of these.
for a linear control system with no poles in RHS of s plane including roots on jw axis with bounded input, output may be unbounded
10. Number of sign changes in the entries in 1st column of Routh array denotes the no. of . roots of characteristic polynomial in RHP.
A. zeroes of system in RHP.
B. open loop poles in RHP.
C. open loop zeroes in RHP.
Number of sign change in the 1st column of routh array denotes number of roots of the system in RH of s plane.
11. A cascade of three linear time invariant systems is causal & unstable. From this we conclude that- . each system in the cascade is individually caused & unstable.
A. at least one system is unstable & at least one system is causal.
B. at least one system is causal & all systems are unstable.
C. the majority are unstable & the majority are causal.
To whole system is causal & unstable .There ,must be at least one system causal & one unstable out of three.
12. In the integral control of the single area system frequency error is reduced to zero. Then . integrator output & speed changer position attain a constant value.
A. integrator o/p decreases but speed changer position moves up.
B. integrator o/p increases but speed changer position comes down.
C. integrator o/p decreases & speed changer position comes down.
In the integral control of single area system, when the system frequency error is reduced to zero, the integrator output & the speed changer position attain a constant value..
13. When the polynomial is Hurwitz, . function is not real.
A. the roots of function have real parts which are to be zero/negative..
B. all zeroes lie in the right half of the s-plane.
C. none of this.
The polynomial is Hurwitz then the roots function have real parts which are to be zero / negative.
14. Time response for a second order system depends on value of ζ. If ζ= 0 then the system is called as . un-damped system.
A. under damped system.
B. critically damped system.
C. over damped system.
the damping ratio is a dimensionless measure describing how oscillations in a system decay after a disturbance. Many systems exhibit oscillatory behavior when they are disturbed from their position of static equilibrium. If ζ is zero then there will be no damping, hence it is called un-damped system.
Where the spring–mass system is completely loss less, the mass would oscillate indefinitely, with each bounce of equal height to the last. This hypothetical case is called un-damped.
15. Time response for a second order system depends on value of ζ. If ζ>1 then the system is called as . un-damped system .
A. under damped system.
B. over damped system.
C. critically damped system.
If the system contained high losses, for example if the spring–mass experiment were conducted in a viscous fluid, the mass could slowly return to its rest position without ever overshooting. This case is called over damped. For over damped system zeta is greater than 1.
16. Time response for a second order system depends on value of ζ. If ζ = 1 then the system is called as . un-damped system.
A. under damped system.
B. over damped system.
C. critically damped system.
between the over damped and under damped cases, there exists a certain level of damping at which the system will just fail to overshoot and will not make a single oscillation. This case is called critical damping.
17. Time response for a second order system depends on value of ζ. If ζ = (0 to 1) then the system is called as . under damped system.
A. un-damped system.
B. over damped system.
C. critical damped system.
Commonly, the mass tends to overshoot its starting position, and then return, overshooting again. With each overshoot, some energy in the system is dissipated, and the oscillations die towards zero. This case is called under damped.
18. For a unity feedback control system open loop transfer function G(s)= 10/s(s+1) then position error constant is
. 0.
A. 20.
B. ∞.
C. 40.
Position error constant is Kp = limit0 {G(s) H(s)} = s0{10/s(s+2)}.
19. For a unity feedback control system open loop transfer function G(s)= 10/s(s+1) then velocity error constant is
. 10.
A. 50.
B. ∞.
C. 0.
velocity error constant is Kv
20. For a unity feedback control system open loop transfer function G(s)= 10/s(s+1) then acceleration error constant is
. 0.
A. 50.
B. ∞.
C. 20.
Acceleration error constant is
Ka = limit s→0 ,s2 G(s) H(s)} = s → 0 ,s2