Multiple choice question for engineering
Set 1
1. Which of the following device can be used for force measurement?
a) Beams
b) Bellows
c) Capsule
d) Bourdon tube
Answer
Answer: a [Reason:] Beams are used for force measuring applications, all other devices listed are used for measuring pressure.
2. Load cells are used for measuring_______________
a) Large weights only
b) Small weights only
c) Weights moving in high speed
d) Slowly moving weights
Answer
Answer: d [Reason:] Load cells are used for measuring weights of slowly moving bodies, so that their weight will be uniformly distributed over load cell surface.
3. Which of the following can be measured using Ring-type load cell?
a) Large weight
b) Small weight
c) Both large and small weights
d) None of the mentioned
Answer
Answer: b [Reason:] Ring type load cell consist of a ring like arrangement to which force is applied. They are used for applications in which measurement of small forces are required.
4. Which of the following arrangements are used in load cells?
a) Tensile strain gauges
b) Compressive strain gauges
c) Both tensile and compressive strain gauges
d) None of the mentioned
Answer
Answer: c [Reason:] Force applied to a load cell is measured using determining tensile and compressive components of strain. Strain gauges are attached to the surface of load cell.
5. Which of the following represents correct relationship for strain in ring-type load cell?
a) (1.08 F R)/(E b t2 )
b) ( F R)/(E b t2 )
c) (1.08 R)/(E b t2 )
d) (1.08 F )/(E b t2 )
Answer
Answer: a [Reason:] (1.08 F R)/(E b t2 ) represents strain measured using ring-type load cell, in which F represents force applied, R represents radius of ring, E represents Young’s modulus of material, b represents axial width and t represents thickness of ring.
6. Which of the following conversion is correct for load cell?
a) Force to strain
b) Force to displacement
c) Force to voltage
d) Both force to strain and force to displacement
Answer
Answer: d [Reason:] Commonly load cell measure applied force using strain gauges, but in some cases force is measured by detecting displacement, that is force to displacement conversion.
7. Diaphragm element can also be used for force measurement.
a) True
b) False
Answer
Answer: a [Reason:] Diaphragm elements acts like flat springs in case of force measurement and can be used for measuring both force and pressure.
8. Which of the following statement is true for force?
a) Force is a scalar quantity
b) Force is a vector quantity
c) Force is a dimensionless quantity
d) None of the mentioned
Answer
Answer: b [Reason:] Force can be described as a vector quantity, in which measurement of magnitude and direction of application is important.
9. Which of the following statement is true for diaphragms?
a) Used for measuring small forces
b) Used for measuring large forces
c) Used for measuring dynamic forces
d) None of the mentioned
Answer
Answer: a [Reason:] Diaphragm elements, being small force capacity is used for measuring small forces only.
10. Load cells are primary transducers.
a) True
b) False
Answer
Answer: a [Reason:] Primary transducers are which converts measurand into mechanical quantities. Load cell converts measurand into strain or displacement which are mechanical quantities and hence load cells are primary transducers.
Set 2
1. Which of the following cannot be used as unit for frequency?
a) Hz
b) BPM
c) RPM
d) S
Answer
Answer: d [Reason:] Frequency is a measure of repetition of a quantity over a specific time interval. S (Second) cannot be used for representing frequency. Hz or hertz is the SI unit representation of frequency, other units are Beats per minute (BPM) and Rotation per minute (RPM).
2. Which of the following represents correct relationship between frequency and angular frequency?
a) ω=2πf
b) ω=πf
c) f=2πω
d) f=πω
Answer
Answer: a [Reason:] Angular frequency is the product of frequency of a system and 2π. Frequency is represented in Hertz and angular frequency is represented in rad/sec.
3. What will be the frequency of a system in which 35 events occur in 7 second?
a) 7Hz
b) 35Hz
c) 5Hz
d) 10Hz
Answer
Answer: c [Reason:] Frequency is the number of occurrence of an event in a given time interval. That is for 35 events in 7 second frequency is 35÷7=5Hz.
4. Which of the following device can be used for measurement of frequency?
a) Voltmeter
b) Ammeter
c) Stroboscope
d) None of the mentioned
Answer
Answer: c [Reason:] Stroboscope is a frequency measuring instrument which uses another reference signal with known frequency. Voltmeter is used for measuring voltage and Ammeter is used for measuring current.
5. All waves in electromagnetic spectrum has same speed in vacuum.
a) True
b) False
Answer
Answer: a [Reason:] All waves in electromagnetic spectrum has same speed in vacuum and their speed will be equal to speed of light c. Hence wavelength can be represented as inversely proportional to frequency.
6. Which of the following frequency range represents audible frequency range of humans?
a) Below 20Hz
b) Between 20Hz and 20 KHz
c) Above 20 KHz
d) All of the mentioned
Answer
Answer: b [Reason:] Audible frequency range means, frequency of sound signal that can hear by humans. Audible frequency range of human is recognized as between 20Hz and 20 KHz.
7. Which of the following is the correct relationship between speed of light in vacuum and frequency of light?
a) c=fλ
b) c=f
c) λ=cf
d) c=λ2
Answer
Answer: a [Reason:] In vacuum product of wavelength and frequency of a light can be equated to speed of light, that is wavelength and frequency are inversely proportional.
8. In a dispersive medium, speed of light depends on frequency.
a) True
b) False
Answer
Answer: a [Reason:] Speed of light is independent on any factors only in vacuum, in dispersive medium it may vary according to wavelength of light. Hence the inverse proportionality may not be always correct here.
9. Which of the following range represents frequency range of rainbow colors?
a) Below 4×1014Hz
b) Between 4×1014Hz and 8×1014Hz
c) Above 8×1014Hz
d) Between 0Hz and 8×1014Hz
Answer
Answer: b [Reason:] Colors of rainbow lies in the frequency range 4 – 8×1014Hz, in which 4×1014Hz represents frequency of red light.
10. What will be the frequency of the signal A sin (4πt+ɸ)?
a) 2Hz
b) 0.5Hz
c) 2πHz
d) 4πHz
Answer
Answer: a [Reason:] Frequency is the ratio of angular frequency and 2π. Here angular frequency is 4π.
Hence frequency= angular frequency ÷ 2π.
Set 3
1. Axis of rotation of wheel in gyroscope is called ____________
a) Spin axis
b) Vertical axis
c) Horizontal axis
d) Angular axis
Answer
Answer: a [Reason:] Spin axis is the axis of rotation of wheel in gyroscope.
2. Gymbels are used for _____________
a) Improving rotational speed
b) Supporting gyro wheel
c) As damping agent
d) None of the mentioned
Answer
Answer: b [Reason:] Gymbels are a part of gyroscope, which is used for supporting gyro wheel of gyroscope.
3. Which of the following represents angular momentum of gyro wheel?
a) jsΩs
b) js
c) js/Ωs
d) None of the mentioned
Answer
Answer: a [Reason:] Angular momentum of gyro wheel is the product of moment of inertia ( js ) and Angular velocity ( Ωs ).
4. Turning of rotor about a third axis when a torque transverse to spin axis is known as ____________
a) Transverse shear
b) Transverse stress
c) Precession
d) Face shear
Answer
Answer: c [Reason:] If a torque is applied about an axis transverse to spin axis, the rotor turns about a third axis which is in quadrature to both. This tilting motion is known as precession.
5. Increase in angular momentum decreases error.
a) True
b) False
Answer
Answer: a [Reason:] increase in angular momentum produces a decrease in precession velocity which is the ratio of τf and Hs (Angular momentum), which in turn decreases error.
6. Which of the following represents condition for ideal gyroscope?
a) Infinite drift of spin axis
b) Infinite speed for gyro meter
c) Very low drift of spin axis
d) None of the mentioned
Answer
Answer: c [Reason:] For an ideal gyroscope, drift of spin axis should be very low, in the order of 10in 12 hours.
7. Which of the following represents characteristic of a rate gyro?
a) More sensitive
b) Soft spring of lower value for K
c) High angular momentum
d) All of the mentioned
Answer
Answer: d [Reason:] Rate gyro is a device which is more sensitive, has a soft spring arrangement with lower value of spring constant K and High angular momentum.
8. Which of the following represents integrating type gyroscope?
a) Zero order system
b) First order system
c) Second order system
d) Third order system
Answer
Answer: b [Reason:] Transfer function of integrating type gyroscope is represented by (Hs/B)/(1+S2), from which it is clear that, Integrating type gyro is a first order system.
9. Integrating type gyroscope has high sensitivity due to ______________
a) High Hs
b) Lower damping coefficient
c) Both high Ha and lower damping coefficient
d) None of the mentioned
Answer
Answer: c [Reason:] Both high angular momentum and lower damping coefficient helps to provide high sensitivity for integrating type gyroscope.
10. Rate gyroscope is a _____________
a) Zero order system
b) First order system
c) Second order system
d) Third order system
Answer
Answer: c [Reason:] Transfer function of gyroscope is given by(Hs/Ks)/(S2/ωn2 + 2Sξ/ωn+1) from which it is clear that, rate gyroscope is a second order system.
Set 4
1. Hall Effect is a/an _____________
a) Electronic
b) Magnetic
c) Galvanic
d) Ionizing
Answer
Answer: c [Reason:] Hall Effect is due to the interaction of magnetic field and moving electric charge which results in the development of forces that alter the motion of charge.
2. At equilibrium Lorentz forces will be ____________ of Hall Effect force?
a) Double
b) Half
c) Equal
d) No proportionality
Answer
Answer: c [Reason:] At equilibrium condition, Lorentz force and Hall Effect force balances each other and they will be equal in magnitude.
3. Which of the following represents correct expression of Lorentz force?
a) EH/b
b) eEH/b
c) eEH
d) None of the mentioned
Answer
Answer: b [Reason:] Magnitude of Lorentz force will be equal to ratio of product of electronic charge and Hall potential with width in meters.
4. Hall potential is inversely proportional to magnetic flux density.
a) True
b) False
Answer
Answer: b [Reason:] Hall potential is always directly proportional to magnetic flux density. Expression is given as EH=BbV; where b is the width and V represents velocity.
5. Hall Effect is clearly visible in _______________
a) Pure conductors
b) Semiconductors
c) Super conductors
d) Metals
Answer
Answer: b [Reason:] Hall coefficient depend on number of free charge carriers and it is clearly visible in semiconductors.
6. Force exerted by magnetic field in Hall Effect transducers is ____________
a) Lorentz force
b) Hall Effect force
c) Magnetic force
d) Electric force
Answer
Answer: a [Reason:] Lorentz force is the force exerted by magnetic field in Hall Effect transducers. On equilibrium condition Lorentz force balances Hall Effect force.
7. Which of the following represents correct expression for Lorentz force?
a) BeV
b) BV
c) eV
d) B
Answer
Answer: a [Reason:] Lorentz force is the product of magnetic flux density, electronic charge and Velocity of charge.
8. Which of the following represents output of Hall Effect transducer?
a) Hall potential
b) emf
c) Applied voltage
d) Lorentz Voltage
Answer
Answer: a [Reason:] Output of Hall Effect transducer is called Hall potential and is denoted by EH.
9. Hall Effect transducers attain equilibrium instantaneously.
a) True
b) False
Answer
Answer: b [Reason:] A time delay of 10-14 is required for a Hall Effect transducer to attain equilibrium.
10. Hall Effect transducer can be used to measure___________
a) Magnetic field
b) Angular displacement
c) Linear displacement
d) All of the mentioned
Answer
Answer: d [Reason:] Hall Effect transducers can be used to measure linear and angular displacement and magnetic field etc.
Set 5
1. Which of the following represents drawback of inductive transducer for displacement measurement?
a) Act of electromagnetic force of attraction
b) Lower sensitivity
c) Requirement of large displacement
d) None of the mentioned
Answer
Answer: a [Reason:] Electromagnetic force of attraction is acted on moving core, and hence displacement source has to overcome this force.
2. Which of the following represents application of inductive transducers?
a) Displacement measurement
b) Thickness measurement
c) Both displacement and thickness measurement
d) None of the mentioned
Answer
Answer: c [Reason:] Inductive transducers can be used for measuring displacement and thickness of thin plate etc.
3. Push-pull coil system is used for ________________
a) Providing constant permeability
b) Minimize electromagnetic force of attraction
c) Provide immunity from external magnetic effect
d) All of the mentioned
Answer
Answer: d [Reason:] Push-pull system is a special type of coil system which has many advantages.
4. Closely wound toroid coils are better than solenoid coil.
a) True
b) False
Answer
Answer: a [Reason:] Closely wound toroid coils provide independence from effect of external magnetic field.
5. Which of the following is correct for toroid type coils?
a) Toroid can be used for measurement of displacement
b) Toroid cannot be used for measuring displacement
c) Toroid can be used for measuring both displacement and velocity
d) None of the mentioned
Answer
Answer: b [Reason:] Toroid cannot be used for measuring linear displacement due to its shape.
6. Which of the following represents materials used for thickness measurement using inductive transducer?
a) Material should be magnetic in nature
b) Material should be magnetic and conducting
c) Material should be magnetic and non-conducting
d) All of the mentioned
Answer
Answer: d [Reason:] Commonly all type of magnetic materials can be used for thickness measurement using inductive transducers.
7. Which of the following device can be used for measuring relative angular displacement between two systems?
a) Tachometer
b) Synchro
c) Speedo meter
d) None of the mentioned
Answer
Answer: b [Reason:] Synchro is a device used for measuring angular displacement between two systems, usually in a machine between two shafts.
8. Which of the following is correct for synchro?
a) Transformer type displacement transducer
b) Inductive type displacement transducer
c) Capacitive type displacement transducer
d) Resistive type displacement transducer
Answer
Answer: a [Reason:] They develop induced emf related to angular position of rotor, hence they are known as transformer type displacement transducer.
9. For thickness measurement, material should have constant permeability and resistivity.
a) True
b) False
Answer
Answer: a [Reason:] Material used for thickness measurement should have constant permeability and resistivity since properties of material should not change while measurement.
10. Inductive potentiometers are used to measure ________________
a) Voltage
b) Current
c) Displacement
d) None of the mentioned
Answer
Answer: c [Reason:] It has same function as linear potentiometers and is used for measuring displacement.