০০। "A control system is unstable, if the open loop frequency response exhibits an amplitude ratio exceeding unity at the crossover frequency." This is __________ criterion.
ক) Bode stability
খ) Nyquist
গ) Routh stability
ঘ) none of these
০১। "An emf of the order of mV is generated when two solutions of different hydrogen ion concentration are separated by a thin glass wall". This is the working principle of a
ক) pH meter
খ) polarimeter
গ) chromatograph
ঘ) polarograph
০২। 0n-off control which is a special case of proportional control, has a band width of about __________ percent.
ক) 100
খ) 75
গ) 25
ঘ) 0
০৩। A barometer measures the __________ pressure.
ক) absolute
খ) gauge
গ) absolute as well as gauge
ঘ) dynamic
০৪। A bimetallic thermometer as compared to industrial mercury in glass thermometer has almost the same
ক) temperature measuring range (- 40°C to 450°C).
খ) accuracy (± 1% of span).
গ) speed of response.
ঘ) all a, b & c.
০৫। A bolometer is
ক) used for the measurement of thermal radiation.
খ) an element which senses optical input and delivers thermal output.
গ) both (a) & (b).
ঘ) neither (a) nor (b).
০৬। A constant volume gas thermometer employing __________ is used to measure sub-zero (i.e., < 0° C) temperature.
ক) helium
খ) hydrogen
গ) nitrogen
ঘ) none of these
০৭। A control system has the following transfer function The initial value of the corresponding time function is
ক) 1
খ) 1/8
গ) 7/8
ঘ) -1
০৮। A first order system with a time constant of 1 min is subjected to frequency response analysis. At an input frequency of 1 radian/min, the phase shift is
ক) 45°
খ) -90°
গ) -180°
ঘ) -45°
০৯। A first order system with unity gain and time constant τ is subjected to a sinusoidal input of frequency w = 1/τ. The amplitude ratio for this system is
ক) 1
খ) 0.5
গ) 1/2
ঘ) 0.25
১০। A magnetic flowmeter is
ক) based on the principle of Faraday's law.
খ) capable of measuring the flow rate of slurries and electrolytes.
গ) based on the linear relationship between the fluid flow rate and the induced voltage.
ঘ) all (a), (b) and (c).
১১। A manometer measures the __________ pressure.
ক) atmospheric
খ) absolute
গ) gauge
ঘ) none of these
১২। A mercury barometer measures the __________ pressure.
ক) atmospheric
খ) gauge
গ) vacuum
ঘ) absolute
১৩। A mercury thermometer can not be used to measure the temperature below the freezing point of mercury, which is __________ °C.
ক) -38.9
খ) -11.9
গ) -60.9
ঘ) -80.9
১৪। A negative gain margin expressed in decibels means a/an __________ system.
ক) stable
খ) unstable
গ) critically damped
ঘ) none of these
১৫। A non-linear chemical system is exemplified by a/an
ক) isothermal CSTR
খ) mixer
গ) non-isothermal CSTR
ঘ) none of these
১৬। A non-linear system will have __________ steady state values.
ক) one
খ) more than one
গ) two
ঘ) three
১৭। A photo electric device in which the resistance of the metal is directly proportional to the light striking on it, is known as photo-conductive cell. Photoelectric transducers are used for the measurement of those parameters, which can be used to produce variation in
ক) light intensity
খ) current
গ) flux density
ঘ) voltage
১৮। A process is initially at steady state with its output y=l for an input u=l. The input is suddenly changed to 2 at time t=0. The output response is y(t)=1+2t. The transfer function of the process is
ক) 2/s
খ)
গ)
ঘ)
১৯। A proportional controller with a gain of Kc is used to control a first order process. The offset will increase, if
