Multiple choice question for engineering
Set 1
1. What is Common Mode Rejection Ratio?
a) Output of a differential amplifier
b) Ability of an amplifier to reject common mode signals
c) Ability of an amplifier to accept common mode signals
d) None of the mentioned
Answer
Answer: b [Reason:] CMRR or common mode rejection ratio of a differential amplifier is the ability to reject common mode signals. For ideal characteristics, amplifier will have infinite CMRR.
2. Which of the following is not a characteristic of ideal op-amp?
a) Zero slew rate
b) Infinite bandwidth
c) Infinite input impedance
d) Zero output impedance
Answer
Answer: a [Reason:] Slew rate is defined as the maximum rate of change of output voltage. For ideal op-amp slew rate should be infinite.
3. For an inverting amplifier positive terminal of input is connected to____________ of 741 IC.
a) Pin number 3
b) Pin number 2
c) Pin number 1
d) Pin number 7
Answer
Answer: b [Reason:] For an inverting amplifier positive terminal of input should be connected to negative input terminal of 741 IC that is pin number 2.
4. In 741 IC, pin number 4 is represented by:
a) Offset null
b) Positive input
c) Negative input
d) Negative supply
Answer
Answer: d [Reason:] In 741 IC pin number 4 is negative supply, which is used to connect negative terminal of supply voltage.
5. Which of the following cannot be treated as a requirement of instrumentation amplifier?
a) Low drift
b) Low input impedance
c) High linearity
d) High CMRR
Answer
Answer: b [Reason:] For an instrumentation amplifier, input impedance should be very high.
6. Amplifier with power supply and output circuits galvanically isolated are called______________
a) Differential amplifier
b) Isolation amplifier
c) Inverting amplifier
d) None of the above
Answer
Answer: b [Reason:] Isolation amplifier is an amplifier with supply and output circuit galvanically isolated. Galvanic isolation means separation of functional units to prevent current flow.
7. Voltage follower is also known as ___________
a) Unity gain amplifier
b) Differential amplifier
c) Comparator
d) None of the mentioned
Answer
Answer: a [Reason:] In unit gain amplifier output follows exact input and is known as voltage follower.
8. Which configuration of op-amp is used for filter circuit?
a) Differential
b) non-inverting
c) Inverting
d) None of the mentioned
Answer
Answer: c [Reason:] Inverting mode of operation is employed for op-amp as a filter circuit, that is high pass and low pass filters.
9. Amplification of low level signal can be done using___________
a) Electrometer amplifier
b) Difference amplifier
c) Inverting amplifier
d) Non inverting amplifier
Answer
Answer: a [Reason:] Electrometer amplifiers are special type of amplifiers used for the amplification of very low level signals.
10. For an ideal op-amp, zero input results in zero output.
a) True
b) False
Answer
Answer: a [Reason:] Zero output for zero input is a characteristic of ideal op-amp. That is there will be no output for zero input.
Set 2
1. Which of the following is caused by careless handling?
a) Systematic error
b) Gross error
c) Random error
d) None of the mentioned
Answer
Answer: b [Reason:] Gross errors are mostly due to lack of knowledge, judgment and care on the part of experiment. That is Gross error is caused by careless handling.
2. ‘A system will be error free if we remove all systematic error’. Is this statement true or false?
a) True
b) False
Answer
Answer: b [Reason:] Random errors will remain in a system even if we remove all systematic errors. Random errors are also known as residual errors.
3. Which of the following is not a fundamental quantity?
a) Length
b) Angle
c) Time
d) Luminous intensity
Answer
Answer: b [Reason:] Derived units are those expressed in terms of fundamental units. Primary or fundamental units cannot be expressed in terms of other units.
4. Which standard is fixed and used for industrial laboratories?
a) International standard
b) Primary standard
c) Secondary standard
d) Working standard
Answer
Answer: c [Reason:] Secondary standards are fixed and used in industrial laboratories. Working standards as its name suggests, is used for day to day measurements. International standards are accepted internationally and primary standards are used in different parts of world which will not be accessible outside for calibration.
5. Which of the following error is caused by poor calibration of instrument?
a) Random error
b) Gross error
c) Systematic error
d) Precision error
Answer
Answer: c [Reason:] Systematic errors are caused by poor calibration of instruments.
6. How systematic errors are eliminated?
a) Frequent measurement
b) Replacement of instrument
c) Finding mean of reading
d) Finding variance of reading
Answer
Answer: b [Reason:] The possible way of eliminating systematic error is replacement of instruments. Systematic errors are caused by poor instrument calibration.
7. Which of the following represents SI unit of luminous intensity?
a) Lumen
b) Candela
c) Dioptre
d) None of the mentioned
Answer
Answer: b [Reason:] SI unit of Luminous intensity is candela represented by cd. Luminous intensity is a Photometric quantity.
8. Starting position of an object is represented as x=5.1±0.2m and finishing position as y=6.9±0.3m. What will be the displacement and error in displacement?
a) Displacement= 1m
Error= 0.5m
b) Displacement= 2m
Error= 0.36m
c) Displacement=1.8m
Error= 0.36m
d) Displacement= 1.5m
Error= 0.4m
Answer
Answer: c [Reason:] Displacement between two positions represented as x±Δx and y±Δy is Iy-xI and error in displacement is (Δx2 +Δy2)1/2.
9. Uncertainty in quantity X is given by ΔX. Then what will be the uncertainty in quantity R for which
R=c.X?
a) |c|.ΔX
b) ΔX⁄|c|
c) ΔX
d) (ΔX)c
Answer
Answer: a [Reason:] Error of a Quantity which is a constant multiple of another quantity will be constant multiple of error of first one.
10. ‘Zero error is an indication of instrumental error’. Is the statement true or false?
a) True
b) False
Answer
Answer: a [Reason:] Zero error refers to false indication of an instrument when true value is zero and zero error can be treated as instrumental error.
Set 3
1. Difference between input signal and feedback signal is known as ____________
a) Feedback factor
b) Error signal
c) Output signal
d) Input signal
Answer
Answer: b [Reason:] Error signal is the difference between input signal and feedback signal. For a negative feedback loop error signal is given by;
e(t)=xi(t) – xf(t)
2. Error signal in positive feedback system will be ____________ input signal.
a) Greater than
b) Lower than
c) Equal to
d) Negative of
Answer
Answer: a [Reason:] In positive feedback signal is added with input signal and obtained error signal.
3. Which of the following represents complete expression for closed loop system?
a) Aβ
b) A/ Aβ
c) A/ (1+Aβ)
d) 1/ (1+Aβ)
Answer
Answer: c [Reason:] A/ (1+Aβ) represents closed loop gain for negative feedback system, for positive feedback system closed loop gain will be A/ (1+Aβ).
4. Which of the following change have been happened to output impedance in negative feedback system?
a) Increases
b) Decreases
c) No change
d) Negative
Answer
Answer: b [Reason:] Output impedance with feedback in negative feedback system is given by;
Rof= Ro/ (1+Aβ)
5. Voltage gain improves on application of negative feedback.
a) True
b) False
Answer
Answer: b [Reason:] Voltage gain with feedback network is given by Af= A/ (1+Aβ), In which gain decreased by a factor 1+Aβ.
6. Input impedance ban be _______________ on application of negative feedback.
a) Increased
b) Decreased
c) Halved
d) Maintained constant
Answer
Answer: a [Reason:] Expression for input impedance on negative feedback is given by Rif=Ro(1+Aβ), in which it is increased by a factor (1+Aβ).
7. For a negative feedback system, A=3 and β=2 and output impedance without feedback is 100Ω. What will be its total output impedance?
a) 14.3 Ω
b) 700 Ω
c) 33.33 Ω
d) 50 Ω
Answer
Answer: a [Reason:] Output impedance with feedback in a negative feedback system is
Rf=Ro/ (1+Aβ)
8. Input impedance of a system is 50 Ω, for the system to be negative feedback, which of the following can be its input impedance without feedback?
a) 50 Ω
b) 60 Ω
c) 40 Ω
d) 100 Ω
Answer
Answer: c [Reason:] For a negative feedback system input impedance increases after feed backing.
9. In a feedback gain equation, what does the term β stands for?
a) Feedback gain
b) Forward gain
c) Open loop gain
d) Closed loop gain
Answer
Answer: a [Reason:] The term β stands for feedback gain and it is the gain of feedback system only.
10. In which of the following conditions, feedback gain (Af) become independent of forward gain (A)?
a) Aβ<<1
b) Aβ=1
c) Aβ>>1
d) Aβ=0
Answer
Answer: c [Reason:] Expression for feedback gain in negative feedback loop is given by;
Af= A/ (1+Aβ)
In which, when Aβ>>1, Af becomes reciprocal of loop gain β.
Set 4
1. In _____________ velocity of fluid is constant on every point at a specific time.
a) Steady flow
b) Rotational flow
c) Non steady flow
d) None of the mentioned
Answer
Answer: a [Reason:] In steady flow fluid, velocity of all points will be constant at a specific time.
2. If all particle of fluid has a path parallel to wall, it is known as ____________
a) Stream line flow
b) Laminar flow
c) Viscous flow
d) All of the mentioned
Answer
Answer: d [Reason:] If all particles of fluid has a parallel path with wall, it is called laminar flow which is also known as viscous flow and stream line flow.
3. Which of the following represents Reynolds number for laminar flow?
a) Less than 2000
b) Greater than 4000
C) Infinite
d) None of the mentioned
Answer
Answer: a [Reason:] Reynolds number is an indication of flow of fluid, For a Reynolds number less than 2000, fluid is said to be in laminar flow. For greater than 4000 fluid is said to be in turbulent flow.
4. Bernoulli’s theorem is applicable for fluid path with moderate frictional force.
a) True
b) False
Answer
Answer: b [Reason:] Bernoulli’s theorem is applied to obtain the total energy of the fluid at each of the two points separated by a distance and in a tapered pipeline. It assumes a frictionless path and viscous forces are negligible.
5. _____________ measures velocity at a point of fluid in a stream.
a) Venturi meter
b) pH meter
c) Pitot-Static tubes
d) None of the mentioned
Answer
Answer: c [Reason:] Pitot-static tubes are the devices used for measuring velocity of fluid.
6. Which of the following represents obstruction type flow measuring systems?
a) Centrifugal force type
b) Rotating vane system
c) Flow nozzle device
d) None of the mentioned
Answer
Answer: c [Reason:] In such systems, flow rate is measured by making an obstruction in the path of flow.
7. Static vane system causes pressure loss in flow.
a) True
b) False
Answer
Answer: a [Reason:] Static vane make an obstruction in the path of fluid flow, which causes considerable pressure loss.
8. Which of the following represents correct relation between flow rate and area of pipe?
a) Direct proportionality
b) Inverse proportionality
c) Equal
d) None of the mentioned
Answer
Answer: a [Reason:] Flow rate and area of cross section of pipe is directly proportional. That is, when area of pipe is increased flow rate also increases.
9. Which of the following converts flow to rotational motion?
a) Rotatic vane system
b) Rotameter flow system
c) Both rotameter flow system and rotatic vane system
d) None of the mentioned
Answer
Answer: a [Reason:] Rotatic vane system is used for measurement of flow rate of fluid, in which flow is converted into rotational motion.
10. Centrifugal force elements are used for ___________
a) High flow rate
b) Low flow rate
c) All range of flow rate
d) None of the mentioned
Answer
Answer: a [Reason:] Centrifugal force element for measuring flow rate is only applicable for high flow rate, below which it doesn’t produce any recognizable change.
Set 5
1. What is the analogous quantity of current in fluidic system?
a) Flow rate
b) Pressure
c) Viscosity
d) Density
Answer
Answer: a [Reason:] Flow rate of a fluid in a path is analogous to current flow in a conductor and both can be treated as analogous quantities.
2. Which of the following device cannot be used for measuring pressure of a liquid?
a) Diaphragm
b) Bellow
c) Bourdon tube
d) pH meter
Answer
Answer: d [Reason:] pH meter is used for measuring pH value of a liquid, all other devices are used for measuring pressure.
3. In laminar flow pressure changes are maximum.
a) True
b) False
Answer
Answer: b [Reason:] A liquid is said to be in laminar flow, if its pressure changes are minimum, otherwise it is said to be in turbulent flow.
4. Which of the following represents liquid manometer?
a) Zero order system
b) First order system
c) Second order system
d) Third order system
Answer
Answer: c [Reason:] From the transfer function of a liquid manometer it is clear that it is a second order system.
5. What is the advantage of pneumatic system over hydraulic system?
a) Gases provide low compressibility
b) Gases provide high compressibility
c) Liquid shows high compressibility
d) None of the mentioned
Answer
Answer: b [Reason:] The advantage of pneumatic system is that, gases show high compressibility which uses minimum space for a volume same as hydraulic system.
6. Which of the following represents liquid manometer?
a) Un-damped system
b) Under damped system
c) Critically damped system
d) Over damped system
Answer
Answer: b [Reason:] Value of damping factor in liquid manometer is far below one and the system represents under damped system.
Damping factor (ξ) =(2µ) / (R2 ϱ) √3L/2g
7. Which of the following represents hydraulic capacitance of manometer?
a) ϱΔV/ΔP
b) ΔV/ΔP
c) ϱΔP/ΔV
d) None of the mentioned
Answer
Answer: a [Reason:] ΔV is the incremental change in volume and ΔP is the incremental change in pressure.
8. Which of the following is not a scalar quantity?
a) Pressure
b) Density
c) Force
d) Viscosity
Answer
Answer: c [Reason:] Force is a vector quantity and all other mentioned quantities are scalar quantities, which have magnitude only.
9. Which of the following is used to represent difference in pressure between absolute zero and atmospheric pressure?
a) Absolute pressure
b) Gauge pressure
c) Differential pressure
d) None of the mentioned
Answer
Answer: b [Reason:] Difference in pressure between absolute zero and local atmospheric pressure is known as gauge pressure, whereas differential pressure is the difference of pressure between two medium.
10. What is the equivalent pressure in Pascal for 1atm pressure?
a) 101.3 Pa
b) 101.3 KPa
c) 50.4 Pa
d) 50.4 Kpa
Answer
Answer: b [Reason:] Pascal and atm are two different units used to indicate pressure values.