Rajasthan Polytechnic Third Year Paper 2016 – System Control & Instrumentation

Rajasthan Polytechnic Third Year Paper 2016 – System Control & Instrumentation

Automatic control is used in refrigeration
(a) To control pressure only
(b) To control temperature only
(c) To control temperature, pressure and humidity only
(d) To control pressure and humidity only

What is the use of thermostate ?
(a) To control temperature
(b) To control pressure
(c) To control pressure and temperature
(d) To contorl temperature and humidity

By which name actuators is known
(a) Primary controller
(b) Lateral controller
(c) Lateral & Primary controller
(d) All of the above

What is the limit of voltage in linear-voltage?
(a) 120 V to 240 V
(b) 240 V to 360 V
(c) 100 V to 110 V
(d) 120 V to 220 V

What is the limit of low-voltage?
(a) upto 25 volt
(b) upto 30 volt
(c) 100 V to 110 V
(d) 120 V to 220 V

By which name proportional controller is known ?
(a) Modulating controller
(b) Automatic controller
(c) Automatic-motor controller
(d) Automatic temperature controller

Oil failure pressur switch is used in
(a) Compressor
(b) Condenser
(c) Evaporator
(d) Expansion valve

Damper is used for
(a) Only to change the direction of air flow
(b) Only to increase the velocity of air
(c) only to relative the velocity of air
(d) None of the above

Thermister is a semi electronic conductor
(a) Whose resistance is changed with change in temperature
(b) Whose resistance is changed with change in voltage
(c) Whose resistance is changed with change in electric current
(d) None of the above

Reset controller is used to
(a) Control the temperature and pressure in cooling and heating medium
(b) Control the volume and heat in cooling and heating medium
(c) Control humidity and temperature in cooling and heating medium
(d) None of the above.