Q. Assertion (A): A large negative feedback is deliberately introduced in an amplifier to make its gain independent of variation in parameters of active device.

Reason (R): A large negative value of feedback results in a high value of return difference compared to unity which makes the feedback gain inversely proportional to the feedback factor.

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Q. An electromechanical device which actuates a train of step angular movements in response to a train of input pulses on one to one basis is

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Q. Assertion (A): If the Laplace transform is G(s) = 4/(s²+2s+4), the Laplaces transform of impulse response is given by C(s) = 4/(s²+2s+4)

Reason (R): The Laplace transform for an impulse function is 1.

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Q. The polar plot of G(jω) = 1/jω is the negative imaginary axis.

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Q. The number of branches of root locus plot is equal to

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Q. The action of bellows is similar to that of

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Q. For a second order system ωn is natural frequency, ωd is frequency of damped oscillations and ζ is damping factor. Then

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Q. In force voltage analogy the quantity analogous to spring constant K is

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Q. The log magnitude curve of factor jω is a straight line having a slope of 20 dB/decade.

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Q. Time rate of change in heat energy is analogous to

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Q. Assertion (A): In control system velocity error is not an error in velocity but is an error in position due to a ramp input.

Reason (R): For a type of system velocity error is zero.

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Q. The shape of torque-speed curve of a two phase servo- motor mostly depends on

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Q. In a lag network the input frequency is 100 fc where fc is critical frequency. The voltage gain is

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Q. Assertion (A): Temperature control of the passenger compartment of car uses both feed forward and feedback controls.

Reason (R): Feed forward control gives corrective action before the disturbance affects the output and feedback control applies corrective action after output changes.

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Q. Assertion (A): Most of actual systems are non-linear.

Reason (R): Non linearity may be due to saturation, dead zone, square law etc.

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Q. The correct sequence of events to improve system stability is

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Q. Assertion (A): For an underdamped system with damping ratio ξ, the maximum overshoot is e-ξπ/(1-ξ²)^0.5

Reason (R): Peak time of a second order under damped system = π/ωd where ωd is frequency of damped oscillations.

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Q. I-PD controlled system has

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Q. Assertion (A): Laplace transform of impulse function is equal to area under the impulse.

Reason (R): An impulse function whose area is unity is called unit impulse function.

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Q. Optical encoders most commonly used in control systems are

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