Multiple choice question for engineering
Set 1
1. Why feedback in accelerometer systems are applied to?
a) To increase range
b) To increase accuracy
c) To increase accuracy and bandwidth
d) None of the mentioned
Answer
Answer: c [Reason:] Feedback in accelerometer systems are applied to provide higher accuracy and bandwidth.
2. Which of the following is measured in open loop accelerometer system?
a) Absolute displacement of proof mass
b) Relative displacement between proof mass and external environment
c) Relative displacement between proof mass and housing
d) None of the mentioned
Answer
Answer: c [Reason:] In open loop accelerometer systems relative displacement between proof mass and housing is measured and corresponding acceleration is measured.
3. PMMC system is used for providing ______________
a) Feedback torque
b) Damping
c) Feedback torque and damping
d) Sufficient magnetic field
Answer
Answer: c [Reason:] Permanent magnet moving coil system is used for feedback torque and sufficient damping for system.
4. Internal torque of the coil, while operation is _____________
a) M.r
b) M.r2
c) M.r2.x’’(t)
d) M.r.x(t)
Answer
Answer: d [Reason:] Internal torque of the coil is the product of proof mass (M), length of spindle of coil (r) and acceleration (x’’(t)).
5. Feedback torque developed due to the application of LVDT will be __________________
a) Equal to inertial torque
b) Greater than inertial torque
c) Less than inertial torque
d) No relation with inertial torque
Answer
Answer: a [Reason:] Feedback torque developed due to the application of LVDT is related to inertial torque and they both are equal in magnitude.
6. Under steady state conditions, inertial torque will be ______________ to output current (Io).
a) Equal
b) Directly proportional
c) Inversely proportional
d) In no relation
Answer
Answer: b [Reason:] Relation is given by product of torque constant Kf and output current Io, and Inertial torque and output current have direct proportionality.
7. The whole feedback accelerometer system will be _________________
a) Zero order system
b) First order system
c) Second order system
d) Third order system
Answer
Answer: c [Reason:] While considering gain of displacement transducer as Kp and amplifier as Ka, system behave as second order system with larger bandwidth than of moving coil system alone.
8. Which of the following methods are employed for improving gain of amplifier?
a) Liquid damping system
b) Air damping system
c) By eliminating damping system
d) Cannot improve gain
Answer
Answer: d [Reason:] Gain of amplifier cannot be increased at will, as other stages of the forward path are likely to possess certain time constant. Very high gain causes instability.
9. System is much unstable at _______________
a) Very low value of gain of amplifier
b) High gain of amplifier
c) Gain specific to a range
d) None of the mentioned
Answer
Answer: b [Reason:] When gain of amplifier is very much high, it behaves as highly unstable.
10. Which of the following will function as integrator of input voltage?
a) Motor of speed inversely proportional to voltage
b) Motor of speed directly proportional to voltage
c) Motor of speed equal to voltage
d) None of the mentioned
Answer
Answer: d [Reason:] A motor of speed directly proportional to applied voltage can function as an integrator of input voltage.
Set 2
1. Which of the following represent temperature at which atmosphere moisture can saturate?
a) Bubble point
b) Dew point
c) Melting point
d) Saturation point
Answer
Answer: b [Reason:] Dew point is the temperature at which atmosphere moisture can saturate air.
2. CRO can be considered as an inverse transducer.
a) True
b) False
Answer
Answer: a [Reason:] In non-contact position measurement CRO can be used and they can consider as inverse transducer.
3. Closed-loop system are also known as manual control system.
a) True
b) False
Answer
Answer: b [Reason:] Open-loop systems are known as manual control system, since automatic loop control is not possible.
4. Which of the following lead to instability?
a) Negative feedback
b) Positive feedback
c) Both positive and negative feedback
d) None of the mentioned
Answer
Answer: b [Reason:] Due to oscillation, chaotic behavior and exponential growth positive feedback causes instability.
5. Which of the following are the application of positive feedback system?
a) Telemetry system
b) Automatic test system
c) Bimorph position control system
d) None of the mentioned
Answer
Answer: d [Reason:] Systems such as telemetry system, automatic test system and bimorph position control system are application of negative feedback system.
6. Which of the following are application of negative feedback system?
a) Mercury thermostat
b) Centrifugal governor
c) Audio amplifier
d) All of the mentioned
Answer
Answer: d [Reason:] Mercury thermostat, centrifugal governor and audio amplifier are negative feedback systems.
7. For a good control system bandwidth should be ____________
a) Very low
b) Ideally zero
c) Very high
d) None of the mentioned
Answer
Answer: c [Reason:] An operating frequency range decides bandwidth of a system and for a good control system, bandwidth should be very high.
8. Time taken by a system to achieve stable state is ______________
a) Oscillation
b) Damping
c) Speed
d) Bandwidth
Answer
Answer: c [Reason:] Speed is the time taken by the system to achieve stable state.
9. Electric hand drier is an example of _____________
a) Open loop control system
b) Closed loop control system
c) Unpredictable
d) None of the mentioned
Answer
Answer: a [Reason:] Electric hand drier is an open loop system in which hot air is supplied as long as system is active.
10. Automatic washing machine is ________________
a) Open loop control system
b) Closed loop control system
c) Unpredictable
d) None of the mentioned
Answer
Answer: a [Reason:] Automatic washing machine works based on pre-set time and irrespective of whether washing completed or not.
Set 3
1. Pneumatic load cells are suitable for measuring ______________
a) Very low pressure
b) Very high pressure
c) Intermediate range of pressure
d) All of the mentioned
Answer
Answer: b [Reason:] Pneumatic and hydraulic load cells are suitable for measuring very high pressure range.
2. Hydraulic cells are preferable since _______________
a) Can be used up to high pressure
b) Faster indication
c) Used for measuring high weights
d) All of the mentioned
Answer
Answer: d [Reason:] Hydraulic cells can be used in pressure up to 29 kg/cm2 and high weight up to 5*106kg.
3. Pressure output and area of diaphragm in pneumatic cell is related by ______________
a) Direct proportionality
b) Inverse proportionality
c) Equal
d) No relation
Answer
Answer: b [Reason:] Output and area of diaphragm is given by
P0= Fi /(A+(1/KdKn))
4. Which of the following is correct for load cell?
a) Force to electrical energy conversion
b) Electrical energy to force conversion
c) Force to force conversion
d) None of the mentioned
Answer
Answer: a [Reason:] Load cells are working based on conversion of force to electrical signal.
5. Load cells are highly stable.
a) True
b) False
Answer
Answer: b [Reason:] Load cell operation is much affected by mechanical factors and also can be damaged by induced current.
6. Which of the following can be used with highly dynamic force?
a) Piezo-electric load cell
b) Strain gauge load cell
c) All of the mentioned
d) None of the mentioned
Answer
Answer: a [Reason:] Piezo-electric load cell can be used with highly dynamic force.
7. Which of the following is suitable for geomechanical measurement?
a) Vibrating wire load cell
b) Strain gauge load cell
c) Piezo electric load cell
d) All of the mentioned
Answer
Answer: a [Reason:] They are more suitable due to low amount of drift.
8. Which of the following may be a cause for ringing in pneumatic load cell?
a) High load
b) Low load
c) Abrupt load change
d) No load
Answer
Answer: c [Reason:] Ringing is a process formed when abrupt load change occurs.
9. Pressure can be directly measured from load cell.
a) True
b) False
Answer
Answer: b [Reason:] Pressure is measured using strain gauge or piezo electric material.
10. Which of the following can be measured using load cell?
a) Displacement
b) Stress
c) Strain
d) All of the mentioned
Answer
Answer: d [Reason:] Load cell can be used to measure displacement, stress and strain on different arrangements.
Set 4
1. OTDR stands for _______________
a) Optical time domain reflectometer
b) Optical transfer data rate
c) Optical time data registers
d) None of the mentioned
Answer
Answer: a [Reason:] OTDR is the short form of optical time domain reflectometer.
2. Which of the following is not correct for fibre optic sensors?
a) Immune to electro magnetic interference
b) Immune to radiation hazard
c) Can be used in harsh environments
d) None of the mentioned
Answer
Answer: d [Reason:] All of the mentioned are qualities of fibre optic sensors.
3. Fluoride glass is used with __________
a) IR waves
b) UV rays
c) Normal light
d) All of the mentioned
Answer
Answer: a [Reason:] Flouride glass are suitable for IR rays of wavelength upto 3200 nm.
4. Silica glass of hydroxyl concentration can be used for ___________ of wavelength.
a) 100 nm to 250 nm
b) 250 nm to 800 nm
c) 800 nm to 1500 nm
d) 100 nm to 3400 nm
Answer
Answer: b [Reason:] Silica glass with hydroxyl concentration is used for wavelength 250 nm to 800 nm.
5. General spectral range for silica glass is _______________
a) Less than 200 nm
b) Between 200 nm to 2200 nm
c) Between 2000 nm to 5000 nm
d) Greater than 3000 nm
Answer
Answer: b [Reason:] General spectral range of silica glass is 200 nm to 2200 nm.
6. Epoxy material in fibre optics is intended for ________________
a) Better optical properties
b) Better reflection
c) Better sealing
d) Reducing noise
Answer
Answer: c [Reason:] Polished epoxy seal provides liquid and air tight seal.
7. Plastics optical cables can be used for ________________
a) Short range
b) Medium range of distance
c) Long range of distance
d) Very high range of distance
Answer
Answer: a [Reason:] Plastic optical cables are manufacturing for short range purposes.
8. Which of the following represents loss associated with glass fibres?
a) 3 dB/Km
b) 10 dB/Km
c) 0 dB/Km
d) 50 dB/Km
Answer
Answer: a [Reason:] Glass fibres have a net loss of 3 dB on every single kilometre.
9. Loss associated with plastic fibre is less than glass fibres.
a) True
b) False
Answer
Answer:b [Reason:] Loss associated with plastic fibre is about 100-1250 dB/Km and it is several times larger than glass fibres.
10. Cladding in glass fibre have high refractive index than core.
a) True
b) False
Answer
Answer: b [Reason:] Cladding in glass fibre is always kept at low refractive index than core.
Set 5
1. One flip-flop unit can store __________ of data.
a) One nibble
b) One bit
c) One byte
d) One kilo-bit
Answer
Answer: b [Reason:] Flip-flop is the basic storage device which can store one bit of data.
2. SR flip-flop stands for ______________
a) State-reset
b) Set-reset
c) Set-recovery
d) Set-reset
Answer
Answer: d [Reason:] SR flip flop stands for set reset flip flop.
3. Which of the following represents D flip flop?
a) Data flip flop
b) Delay flip flop
c) Direct flip flop
d) Decode flip flop
Answer
Answer: b [Reason:] D flip flop is delay flip flop in which input data is transmitted to output with a delay of one clock pulse.
4. SR flip flop have undefined state when______________
a) Both inputs are low
b) Both inputs are high
c) One input is low
d) None of the mentioned
Answer
Answer: b [Reason:] SR flip flop output changes indefinitely when two inputs are high.
5. Latch is a circuit which operate according to clock pulse.
a) True
b) False
Answer
Answer: b [Reason:] Latch circuit operate according to enable signal. If EN pin is high latch become ON.
6. Race around condition can be rectified by ___________
a) SR flip flop
b) JK flip flop
c) JK master slave flip flop
d) D flip flop
Answer
Answer: c [Reason:] Race around condition is the change of output for more than once during a single clock pulse. It can be rectified by using master save flip flop.
7. Which of the following is an application of flip-flop?
a) Shift register
b) Latch
c) Gates
d) All of the mentioned
Answer
Answer: a [Reason:] Shift register is used for shifting data serially or parallel, flip flop is the basic building block of shift register.
8. If SET pin is active, output becomes ______________
a) High
b) Low
c) Undefined
d) None of the mentioned
Answer
Answer: a [Reason:] SET pin is used to make flip flop output to a known state.
9. In SR flip flop if both inputs are low, output becomes _______________
a) High
b) Low
c) No change
d) Undefined
Answer
Answer: c [Reason:] In SR flip flop if both inputs are low output remains unchanged from previous state.
10. Which of the following is not a sequential circuit?
a) Flip flop
b) Counter
c) Logical gate
d) Shift register
Answer
Answer: c [Reason:] Sequential circuits are those in which previous output.