EC Engineering Automatic Control Systems Online Test

Mechanical impedance is the ratio of

Whether a linear system is stable or unstable that it

If a system is to follow arbitrary inputs accurately the bandwidth should be

Assertion (A): Potentiometers can not be used as error detectors in position control systems.

Reason (R): The resolution of a potentiometer places an upper limit on its accuracy

A stepper motor is

From the noise point of view, bandwidth should

When a unit step voltage drives a lag network the output

A system has its two poles on the negative real axis and one pair of poles lies on jω axis. The system is

Bellows converts

Assertion (A): The steady state response, of a stable, linear, time invariant system, to sinusoidal input depends on initial conditions.

Reason (R): Frequency response, in steady state, is obtained by replacing s in the transfer function by jω

The phase margin and damping ratio have no relation.

The log magnitude curve for a constant gain K is a

A lag compensator is essentially a

Stepper motors find applications in

For type 2 system, the magnitude and phase angle of the term (jω)2 in the denominator, at ω = 0, are respectively

In an integral controller

Bode magnitude plot is drawn between

In a minimum phase system

The entries in the first column of Routh array of a fourth order are 5, 2, – 0.1, 2, 1. The number of poles in the right half plane are

The magnitude of transport lag factor is always zero.

The primary function of lag compensator is to provide sufficient

The polar plot of a transfer function passes through (-1, 0) point. The gain margin is

In control systems the magnitude of error voltage

The slope of log-magnitude asymptote changes by – 40 dB/ decade at a frequency ω1. This means that

The frequency at which magnitude of closed loop frequency response is 3 dB below its zero frequency value is called critical frequency.

In a second order system, the time constant t of exponential envelopes depends

Assertion (A): When the phase margin of a control system is improved using a lead network, noise transmission increases.

Reason (R): Phase lead compensation increases bandwidth.

Assertion (A): Positive feedback is not used in any circuit.

Reason (R): Positive feedback leads to instability.

If the Nyquist plot does not encircle the (-1 + j0) point the system is always stable.

The current rating of dc tachogenerator is usually