Electronics Solved Quiz on circuit theory

Electronics Solved Quiz on circuit theory
Circuit Theory Solved Question
1. Ohm’s law applicable for
(a) linear circuits only
(b) non linear circuits only
(c) both linear and non linear circuits
(d) none of these
Ans: a
2. Unit of current is
(a) Ampere
(b) Volt
(c) Watt
(d) Volt-ampere
Ans: a
3. What is the equivalent resistance when 10 Ohms and 20 Ohms resistors are connected
in series
(a) 35 Ohms
(b) 25 Ohms
(c) 30Ohms
(d) none of these
Ans: c
4. Form factor is defined as the ratio of
(a) Average value to Maximum value
(b) Maximum value to Average value
(c) Peak value to R.M.S Value
(d) R.M.S Value to Average value
Ans: d
5. R.M.S Value of full wave rectified sinusoidal voltage is
(a) V_M/3
(b) V_M/2
(c) V_M/Ö2
(d) none of these
Ans: c
6. Power factor for resistive load is
(a) Zero
(b) Unity
(c) Infinity
(d) 0.2
Ans: b
7. voltage is a ------quantity
(a) Scalar
(b) Vector
(c) Scalar and Vector
(d) none of these
Ans: b
8. In D.C , Capacitor acts as
(a) Short circuit
(b) Open circuit
(c) either (a)or (b)
(d) none of these
Ans: b
9 In 3 phase star circuit, phase voltage is
(a) V_Ph =Ö3 V_L
(b) V_Ph = V_L /Ö3
(c) V_Ph = V_L
(d) V_Ph =3 V_L
Ans: b
10. In 3 phase delta circuit, line current is
(a) I_L =I _Ph
(b) I_L =2 I _Ph
(c) I_L =3 I _Ph
(d) I_L =Ö3 I _Ph
Ans:d
11. What is the equivalent resistance when 20Ohms and 20Ohms resistors are
connected in parallel
(a) 45 Ohms
(b) 10Ohms
(c) 54 Ohms
(d) 30Ohms
Ans: b
12. Voltage-Current relationship in resistor element is
(a) In phase
(b) Out of phase
(c) No Relation
(d) constant
Ans:a
13. For high voltage applications which type of 3 phase circuit to be Preferred
(a) Star
(b) Delta
(c) Star or Delta
(d) Neither Star nor Delta
Ans: b
14. What is the unit of Reactive Power
(a) KVA
(b) KW
(c) HP
(d) KVAR
Ans:d
15. R.M.S Value of Half wave rectified sinusoidal voltage is
(a) V_M/3
(b) V_M/2
(c) V_M/Ö2
(d) none of these
Ans: b
16. Current is defined as
(a) Charge/time
(b) Time/charge
(c) power/time
(d) None of these
Ans:a
17. Active elements are
(a) Voltage sources only
(b) Current sources only
(c) Resistors only
(d) Both Voltage and Current sources
Ans: d
18. In Bilateral Network the current flows in
(a) Unidirectional
(b) Bidirectional
(c) Rotational
(d) None of these
Ans: b
19. D.C has
(a) Constant magnitude
(b) Variable magnitude
(c) Fixed Polarities
(d) Constant magnitude and Fixed Polarities
Ans: d
20. In Capacitive circuit, Current flows in the capacitor
(a) i=C (dv/dt)
(b) i=V(dc/dt)
(c) i=C(di/dt)
(d) i=Ct
Ans: a
21. Unit of voltage is
(a) Ampere
(b) Volt
(c) Watt
(d) Volt-ampere
Ans: b
22. Peak factor is defined as the ratio of
(a) Average value to Maximum value
(b) Maximum value to Average value
(c) Peak value to R.M.S Value
(d) R.M.S Value to Average value
Ans: c
23. Average value is
(a) area/period
(b) period/area
(c) length/area
(d) none of these
Ans: a
24. Unit of power is
(a) Ampere
(b) Volt
(c) Watt
(d) joules
Ans:c
25. Unit of apparent power is
(a) Ampere
(b) Volt
(c) Watt
(d) Volt-ampere
Ans:d
26. Unit of energy is
(a) KWH
(b) Volt
(c) Watt
(d) Volt-ampere
Ans:a
27. A.C has
(a) Constant magnitude
(b) Variable magnitude
(c) Fixed Polarities
(d) Constant magnitude and Fixed Polarities
Ans: b
28. Passive elements are
(a) Voltage sources only
(b) Current sources only
(c) Resistors ,inductors and capacitors
(d) Both Voltage and Current sources
Ans: c
29. In D.C , inductor acts as
(a) Short circuit
(b) Open circuit
(c) both (a)&(b)
(d) none of these
Ans: a
30. In Unilateral Network the current flows in
(a) Unidirectional
(b) Bidirectional
(c) Rotational
(d) None of these
Ans: a
31. Workdone is
(a) F.d
(b) E/F
(c) IR
(d) None of these
Ans: a
32. Unit of Resistance is
(a) Ampere
(b) Volt
(c) Watt
(d) ohms
Ans: d
33. Unit of inductance is
(a) Ampere
(b) Volt
(c) Watt
(d) henry
Ans: d
34. Unit of capacitance is
(a) Ampere
(b) farad
(c) Watt
(d) henry
Ans: b
35. For high current applications which type of 3 phase circuit is Preferred
(a) Star
(b) Delta
(c) Star or Delta
(d) Neither Star nor Delta
Ans: a
36. For low voltage applications which type of 3 phase circuit to be Preferred
(a) Star
(b) Delta
(c) Star or Delta
(d) Neither Star nor Delta
Ans: a
37. Unit of charge is
(a) Ampere
(b) coulomb
(c) Watt
(d) henry
Ans: b
38. EMF is
(a) Election motion force
(b) Electrical motion force
(c) Electro motive force
(d) None of these
Ans: c
39. MMF is
(a) Magnetic motive force
(b) Magnetic motion force
(c) Magneto motive force
(d) None of these
Ans: c
40. Voltage-Current relationship in inductor element is
(a) In phase
(b) 90 (lead)
(c) 90 (lag)
(d) constant
Ans: c
41. Voltage-Current relationship in capacitor element is
(a) In phase
(b) 90 (lead)
(c) 90 (lag)
(d) constant
Ans: b
42. When two inductors are connected in series, equivalent inductance is
(a) L1+L2
(b) 1/(L1+L2)
(c) L1.L2
(d) None of these
Ans: a
43. When two capacitors are connected in series, equivalent capacitance is
(a) C1+C2
(b) 1/(C1+C2)
(c) L1.L2
(d) (1/c1)+(1/c2)
Ans: d
44. R.M.S Value of full wave rectified sinusoidal voltage is
(a) V_M/3
(b) V_M/2
(c) V_M/Ö2
(d) none of these
Ans:c
45. Form factor of full wave rectified sinusoidal voltage is
(a) 1.21
(b) 1.11
(c) 4.44
(d) none of these
Ans: b
46. Power factor for pure inductor
(a) 0(lead)
(b) 0
(c) 0(lag)
(d) none of these
Ans: c
47. Power factor for pure capacitor
(a) 0(lead)
(b) 0
(c) 0(lag)
(d) none of these
Ans: a
48. Frequency is defined as
(a) No of cycles/sec
(b) time/cycles
(c) 1/cycles
(d) None of these
Ans: a
49. In Series resistive circuit, voltage across each resistor is
(a) divided
(b) constant
(c) no change
(d) None of these
Ans: a
50. In Series resistive circuit current through each resistor is
(a) divided
(b) same
(c) 0
(d) None of these
Ans:b
51. When two inductors are connected in parallel, equivalent inductance is
(a) L1+L2
(b) (1/L1)+(1/L2)
(c) L1.L2
(d) None of these
Ans: b
52. When two capacitors are connected in parallel, equivalent capacitance is
(a) L1+L2
(b) (1/L1)+(1/L2)
(c) C1+C2
(d) None of these
Ans:c
53.A sinusoidal Wave form is
a)sine wave form
b) triangle wave form
c) both(a)&(b)
d)none of these
Ans:a
54. In 3 phase delta circuit, phase voltage is
(a) V_Ph =Ö3 V_L
(b) V_Ph = V_L /Ö3
(c) V_Ph = V_L
(d) V_Ph =3 V_L
Ans: c
55. In 3 phase star, line current is
(a) I_L =I _Ph
(b) I_L =2 I _Ph
(c) I_L =3 I _Ph
(d) I_L =Ö3 I _Ph
Ans:a

Free Online Practice test on Electronics

Free Online Practice test  on Electronics
Free Electronics Online Practice Test
Free Online Electronic Engineering Practice and Preparation test
1. UPS is
a. Uninterrupted power supply
b. Unlimited power supply
c. United power supply
d. None of these
Ans. a
2. UPS is a device which maintains continuous supply of ______ to the system connected
a. Electric power
b. Magnetic power
c. EMF
d. Resistance
Ans. a
3. _________ Supplies power when utility is not available.
a. AC mains
b. DC mains
c. UPS
d. SMPS
Ans. C
4. Types of UPS are
a. Switch on and offline UPS
b. Off line and on line UPS
c. Standard and normal ups
d. Power UPS
Ans. b
5. Diode is a combination of
a. Two electrons
b. Two electrodes
c. Two elements
d. Two capacitors
Ans. b
6. How many types of crystal diode rectifiers are there?
a. 2
b. 3
c. 4
d. 5
Ans. a
7. In half wave rectification, the rectifier conducts current only in _____of input ac supply.
a. Positive half cycle
b. Negative half cycle
c. Neutral
d. Both a and b
Ans. a
8. RMS value of current in half wave rectifier is
a. Im/?2
b. Im/2
c.2Im/Em
d. Em/2
Ans b
9. The transformer isolates the rectifier circuit form power line and thus reduces
a. Electric shock
b. Current loss
c. Resistance loss
d. Transformer
Ans. a
10. The pulsations in the output are further smoothening with the help of _________circuit.
a. Transformer
b. Diode
c. Filter
d. Transistor
Ans. c
11. The ratio of dc power output to the applied input of rectifier is known as
a. Power
b. Rectification efficiency
c. Utility factor
d. Working efficiency
Ans. b
12. In half wave rectification, a maximum of _______of ac power is rectifier.
a. 40%
b. 40.6%
c. 40.9%
d. 80.1%
Ans. b
13. The rectifier which contains 2 diodes is called
a. Full wave rectifier
b. Half wave rectifier
c. Centre – tap rectifier Full wave rectifier
d. Bridge full wave rectifier
Ans. c
14. Bridge full wave rectifier consists of ………… number of diodes.
a. 2
b. 3
c. 4
d. 6
Ans. c
15. The efficiency of full wave rectifier is
a. 40%
b. 40.6%
c. 81.2%
d. 80% Ans. c
16. A power supply which maintains the voltage constant irrespective of ac main fluctuations or load variations is known as
a. DC power supply
b. DC regulated power supply
c. Steady power supply
d. None of these
Ans. B
17. A dc regulate supply uses a for power regulation.
a. Transformer
b. Transistor
c. Capacitor
d. Zener diode
Ans. d
18. The process in which an ac voltage is converted into a unidirectional dc voltage is known as
a. Rectification
b. Conversion
c. Transformation
d. Regulation
Ans. a
19. When forward biased, junction diode offers
a. High resistance
b. Low resistance
c. No resistance
d. None of these
Ans. b
20. In the rectifier circuits the ac supply form mains is given through ______ for transformation.
a. Amplifier
b. Transformer
c. Diode
d. Load resistor
Ans. b
21. The ac supply to be rectified in half wave rectifier is applied in series with
a. Diode and load resistance
b. Load resistance and transformer
c. Diode and regulated power supply
d. Two diode
Ans. a
22. An AC rectifier which rectifies both the positive and negative ac half cycles of input wave are called
a. Half wave rectifier
b. Full wave rectifier
c. Transformation rectifier
d. None of these
Ans. b
23. In full – wave rectifier the direction of current in load resistor is ____________ for both half cycles of ac.
a. Opposite
b. Same
c. Different
d. None of these
Ans. b
24. The expression for peak inverse voltage, in case of centre – tap full wave rectifier is
a. 2Vm
b. Vm
c. Vm/2
d. 3Vm
Ans. a
25. In on line UPS ________ batteries are used earlier
a. semiconductor
b. ionic
c. Lead – acid
d. Ordinary
Ans. b
26. Large UPS units typically work in conjunction with
a. Motor
b. Batteries
c. Generator
d. Transformer
Ans. c
27. SMPS are classified into _______ types depending up its input / output.
a. 3
b. 2
c. 4
d. 6
Ans. c
28. SMPS with ac input and dc output is used as
a. Current converter
b. Frequency changer
c. Rectifier
d. cycle converter
Ans. c
29. SMPS with dc input and ac output is used as
a. Current converter
b. Frequency changer
c. Rectifier
d. Inverter
Ans. d
30. Linear power supplies use a transformer operating at the mains frequency of ______ Hz.
a. 50
b. 60
c. 50 or 60
d. none of these
Ans. C
31. SMPS use transformer operating at the frequency of ___________
a. 50 Hz to 1 kHz
b. 50 kHz to 1 kHz
c. 5 kHz to 1MHz
d. 50 kHz to 10MHz
Ans. b
32. The applied ac power to a half wave rectifier is 100W the ac output power obtained is 40W.the rectification efficiency is
a. 30%
b. 40%
c. 50%
d. 60%
Ans. b

Sample Questions Electrical Engineering Basede on Actual Questions of UPSC IAS

Sample Questions Electrical Engineering Basede on Actual Questions of UPSC IAS
Engineering Question UPSC based on Real Question Papers
IAS Prelims Papers Free online solved Questions of Electrical Engineering


1. In India, the maximum frequency deviation in commercial FM broadcasting signals is about
(a) 5 kHz
(b) 15 kHz
(c) 75 kHz
(d) 200 kHz

Ans:-B


2. If the antenna diameter in a radar system is increased by a factor of 4, the maximum range will be increased by a factor of
(a) √2
(b) 2
(c) 4
(d) 8

Ans:-A

3. For any amplifier configuration using a BJT, the input Impedance R i is
(a) h i (l + h fe )
(b) h i / (1—h r Av)
(c) h i / (1+h r Av)
(d) h i / (1 + h fe )

Ans:-B

4. The range of numbers that can be represented in two’s complement mode with four binary digits is
(a) —15 to +15
(b) —8 to + 8
(c) —8 to +7
(d) —7 to +7

Ans:-A

5. Cycle time of a Random Access Memory is the time required between successive
(a) accesses to memory
(b) clocks
(c) delete operations
(d) Read / Write operations

Ans:-A


6. The INTEL 8080 microprocessors has a set of 91 Instructions. The op-code to Implement this Instruction set should be of at least
(a) 6 bits
(b) 4 bits
(c) 7 bits
(d) 8 bits

Ans:-C






7. Consider the following assembly language code for a simple computer having one register only:
LOAD X
ADD Y
STORE T1 STORE T2
MULT Z MULT T1
ADD T2 STORE R
Which one of the following arithmetic expressions does it evaluate?
(a) R:Z2(1+X+Y)2
(b) R:Z2(X+Y)2+(X+Y)
(c) R:=Z(X+Y)2+(X+Y)2
(d) R:=Z(X+Y)2+(X+Y)

Ans:-D


8. Consider the following statements regarding a ‘smart’ terminal:
1. It is a minimal system containing almost no memory.
2. It contains a small microcomputer or minicomputer.
3. It permits text editing.
4. It enables checking of typing errors made by operators.
Which of these statements are correct?
(a) 1, 2 and 3
(b) 1, 2 and 4
(c) 2, 3 and 4
(d) 1, 3 and 4

Ans:-C

9. The unit step response of a second order linear system with zero initial states is given by c (t) = 1 + 1.25 exp (— 6t) sin (8t — tan-1 1.333), t ≥ 0.
The damping ratio and the undamped natural frequency of oscillation of the system are respectively
(a) 0.6 and l0 rad/s
(b) 0.6 and l2.5 rad/s
(c) 0.8 and l0 rad/s
(d) 0.8 and 12.5 rad/s

Ans:-A


10. Type of a system depends on the
(a) number of its poles
(b) difference between the number of poles and zeros
(c) number of its real poles only
(d) number of poles it has at the origin

Ans:-D


11. The final value of function F(s) = 5 / s (s 2 + s + 2)
is equal to
(a) zero
(b) 2 / 5
(c) 5/2
(d) 5

Ans:-C

12. Consider the following statements:
1. P-D controller is equivalent to a high pass filter.
2. For better performance, integral action s initiated before derivative action.
3. High proportional gain is an alternative to derivative action.
4. A practical PID controller uses a high gain amplifier in the forward path.
Which of these statements are NOT correct?
(a) 1, 2 and 4
(b) 2, 3 and 4
(c) 2 and 3
(d) l and 4

Ans:-C

13. In measuring the distributed capacitance ‘C d’ of a certain coil using Q-meter, initial resonance at frequency 2 MHz is obtained by tuning the capacitance set to 430pF. If resonance at 4MHz is obtained by tuning the capacitance set to 100 pF, then the value of ‘C d’ would be
(a) 10 pF
(b) 20 pF
(c) l00 pF
(d) 200 pF

Ans:-A

14. Match List I (Measurements). with List II (Transduction principles) and Select the correct answer using the codes given below the Lists:
List I
A. rpm
B. Temperature
C. Static pressure
D. Current
List II
1. Variable resistance
2. Hall effect
3. Piezoelectric effect
4. Variable reluctance
5. Variable capacit4nce
Codes:
A B C D
(a) 4 1 5 2
(b) 1 4 5 2
(c) 2 1 3 5
(d) 4 1 2 3

Ans:-A


15. A resistance strain gauge with a gauge factor of 2 is fastened to a steel member subjected to a stress of 10.5 x 10’ kN/m2. The modulus of elasticity of steel is 2.1 x k N /m2. The change of resistance due to stress in the strain gauge is
(a) 0.1%
(b) 0.2%
(c) 1%
(d) 10%

Ans:-A


16. How many comparators are there In an ADC with 0— 5V Input and 8 bit output assuming a flash converter?
(a) 5
(b) 8
(c) 40
(d) 255

Ans:-D



17. The ratio of the electrical resistance of a material at 300 K to Its electrical resistance at 4 K is 5.
This material could be
(a) an intrinsic semiconductor
(b) an extrinsic semiconductor
(c) an insulator
(d) a conductor

Ans:-D



18. In a ferromagnetic material, the magnetic field is Increased gradually from zero. The first process which sets in the material to give net magnetization is the
(a) growth of favourable oriented domains at
the cost of other domains by reversible domain wall movement
(b) growth of favourable oriented domains at the cost of other domains by irreversible domain wall movement
(c) alignment of domain walls with the grain boundaries
(d) rotation of domains in the direction of the applied field.

Ans:-C

19. For the epitaxial growth of material M to be possible on the substrate of material N,
(a) the lattice constants of M and N must be same
(b) M and N must not react with each ‘other
(c) the coefficients of thermal expansion of M and N must be equal
(d) M must have a lower density than N

Ans:-A


20. Silicon nitride is used as the cover layer in MOS technology because it is
(a) easy to deposit
(b) resistant to oxidation
(c) an excellent barrier to alkali ions
(d) an excellent mask for gallium

Ans:-B

Transducrs MCQ Questions

Transducrs MCQ Questions
1. The transducers which requires an external power and their output is a measure of some variation such as resistance, inductance, capacitance etc., are called as
a) Active transducer
b) Primary sensor
c) Passive transducer
d) Self generating transducer
Ans : (c)

2. The principle of operation of variable resistance transducer is
a) Deformation leads to change in resistance
b) Displacement of a contact slider on a resistance
c) Coupling of two coils changes with displacement
d) Movement of magnetic field produces variation in resistance of material
Ans : (b)

3. The application of LVDT is
a) Joint motion
b) Finger movement
c) Limb movement
d) Heart wall motion
Ans : (c)

4. Venturi is associated with
a) Venous blood pressure
b) Digital plethysmography
c) Dialysate flow in artificial kidney
d) Blood flow in heart lung machine
Ans : (d)

5. Pressure transducer for measuring blood pressure is
a) Strain gauge transducer only
b) Strain gauge or capacitive transducer
c) Resistive transducer
d) Fiber optic transducer
Ans : (b)

6. The change in resistance of a metal wire owing to strain is due to
S1: Change in dimension of wire expressed by factor (1-2µ)
S2: Change in resistance ∆ρ
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans : (b)

7. In foil strain gauge the thickness of foil varies from
a) 2.5 micron to 6 micron
b) 25 micron (or) less
c) 25 micron to 60 micron
d) 2.5 micron to 5 micron
Ans : (a)

8. In variable capacitance transducer, C=
a) kξo/Ad
b) kξoA/d
c) kξod/A
d) Aξo/kd
Ans : (b)

9. Photo conductive cell consists of a thin film of
a) Quartz
b) Lithium sulphate
c) Barium titanate
d) Selenium
Ans : (d)



10. Test electrode is also known as
a) Indicator electrode
b) Reference electrode
c) Second electrode
d) Primary electrode
Ans : (a)

11. Most commonly used indicator electrode is
a) Calomel electrode
b) Silver electrode
c) Silver – Silver chloride electrode
d) Glass electrode
Ans : (d)

12. _____________ is the example of photo emissive cell
a) LDR
b) Photo diode
c) Photo transistor
d) Photo multiplier
Ans : (a)

13. pH value of venous blood is
a) 7.30
b) 7.40
c) 7.35
d) 7.45
Ans : (c)

14. Silver chloride electrode is used as a reference electrode due to its
a) Large half cell potential
b) Stable half cell potential
c) Stable resting potential
d) Stable action potential
Ans : (b)

15. The capacitance microphone is used for the detection of
a) Heart rate
b) Blood flow
c) Heart sound
d) Foot pressure
Ans : (c)

16. Inductance of a coil is given by L =
a) N2R
b) N2 + R
c) N2 - R
d) N2 / R
Ans : (d)

17. ______________ is called as linistor when it provides a linear change in resistance with respect to temperature
a) Thermistor
b) Thermocouple
c) Thermometer
d) Thermo resistive transducer
Ans : (a)

18. Photo multiplier consists of
a) 1 Photo emissive cathode & 2 dynodes
b) 2 Photo emissive cathodes & 2 dynodes
c) 2 Photo emissive cathodes & 1 dynode
d) 1 Photo emissive cathode & 1 dynode
Ans : (a)

19. Selenium photo cells are sensitive to the visible spectrum of
a) 400 – 700 mµ
b) 350 – 700 mµ
c) 300 – 700 mµ
d) 450 – 700 mµ
Ans : (c)

20. The resistance of LDR ________________ when exposed to radiant energy.
a) Remains unaltered
b) Increases
c) Reaches maximum
d) Decreases
Ans : (d)

21. Respiratory volume is measured using
a) Myograph
b) Pneumograph
c) Spiro meter
d) Goniometer
Ans : (b)

22. Match the following
1. Sensitivity A. Ability to detect very small change
2. Stability B. Ability to produce constant output
3. Precision C. Measure of reproducibility
4. Accuracy D. Closeness to true value
a) 1- B, 2 - A, 3 - C, 4 - D
b) 1 - B, 2 - A, 3 - D, 4 - C
c) 1- C, 2 - A, 3 - B, 4 - D
d) 1 - A, 2 - B, 3 - C, 4 - D
Ans : (d)

23. Piezo electric materials have ___________ resistivity
a) Zero
b) Infinite
c) Finite
d) Null
Ans : (c)

24. Dummy gauge is mounted on the opposite arm of the active gauge to cancel output differentials due to
a) Temperature variation of resistance
b) Pressure variation of resistance
c) pH concentration variation
d) Change in blood flow
Ans : (a)

25. For fiber optic sensors,
a) Single mode transmission is used
b) Multimode transmission is used
c) Both single mode and multimode transmission is used
d) Transmission is not used
Ans (a)

26. One of the combination of materials used for optical fibers are ___________
a) Copper core and glass cladding
b) Glass core and aluminum cladding
c) Glass core and plastic cladding
d) Plastic core and glass cladding
Ans (c)

27. The optical sensors may be classified as _________
a) Intensity and intrinsic types
b) Interferometric and extrinsic types
c) Intensity or intrinsic type and Interferometric or extrinsic types
d) Only extrinsic type
Ans (c)

28. In a graded index fiber, the total reflected light takes a ___________
a) Straight line path
b) Parabolic path
c) Elliptical path
d) Circular path
Ans (b)

29. ____________ fiber is used in interferometric instruments.
a) Monomode
b) Multimode
c) Birefringent
d) Coated
Ans (a)

30. Fiber optic sensor can be used to sense _________
a) Displacement
b) Power
c) Current
d) Resistance
Ans (a)


31. S1: In multimode fiber optics, intensity modulating schemes can be employed.
S2: Schemes using polarizing techniques need birefringent fiber.
a) S1 is true and S2 is false
b) Both S1 and S2 are true
c) S1 is false and S2 is true
d) Both S1 and S2 are false
ans (b)

TRANSDUCERS Quiz Electronics Instrument Engineering

TRANSDUCERS Quiz Electronics Instrument Engineering


1. Self generating type transducers are ___________ transducers.
a) Active
b) Passive
c) Secondary
d) Inverse
Ans : (a)

2. The transducers that converts the input signal into the output signal, which is a discrete function of time is known as ___________ transducer.
a) Active
b) Analog
c) Digital
d) Pulse
Ans : (c)

3. A transducer that converts measurand into the form of pulse is called
a) Active transducer
b) Analog transducer
c) Digital transducer
d) Pulse transducer
Ans : (d)

4. Which of the following is a digital transducer?
a) Strain gauge
b) Encoder
c) Thermistor
d) LVDT
Ans : (b)

5. Strain gauge, LVDT and thermocouple are examples of
a) Active transducers
b) Passive transducers
c) Analog transducers
d) Primary transducers
Ans : (c)

6. An inverse transducer is a device which converts
a) An electrical quantity into a non electrical quantity
b) Electrical quantity into mechanical quantity
c) Electrical energy into thermal energy
d) Electrical energy into light energy
Ans : (a)

7. A strain gauge is a passive transducer and is employed for converting
a) Mechanical displacement into a change of resistance
b) Pressure into a change of resistance
c) Force into a displacement
d) Pressure into displacement
Ans : (a)

8. Resolution of a transducer depends on
a) Material of wire
b) Length of wire
c) Diameter of wire
d) Excitation voltage
Ans : (c)

9. The gauge factor is given as
a) ∆R/R
∆I/I
b) ∆I/I
∆R/R
c) ∆R/R
∆D/D
d) ∆D/D
∆R/R
Ans : (a)

10. The gauge factor G and the poisons ratio µ are related as
a) G = 1+µ
b) G = µ
c) G = 1+2µ
d) G = 1+µ /2
Ans : (a)

11. The sensitivity factor of strain gauge is normally of the order of
a) 1 to 1.5
b) 1.5 to 2.0
c) 0.5 to 1.0
d) 5 to 10
Ans : (b)

12. In wire wound strain gauges, the change in resistance is due to
a) Change in diameter of the wire
b) Change in length of the wire
c) Change in both length and diameter
d) Change in resistivity
Ans : (c)

13. Bonded wire strain gauges are
a) Exclusively used for construction of transducers
b) Exclusively used for stress analysis
c) Used for both stress analysis and construction of transducer
d) Pressure measurement
Ans : (c)

14. Certain type of materials generates an electrostatic charge or voltage when mechanical force is applied across them. Such materials are called
a) Piezo-electric
b) Photo-electric
c) Thermo-electric
d) Photo-resistive
Ans : (a)

15. Quartz and Rochelle salt belongs to ___________ of piezo-electric materials
a) Natural group
b) Synthetic group
c) Natural or Synthetic group
d) Fiber group
Ans : (a)

16. Which of the following are piezo electric substances?
1. Barium titanate
2. Lead titanate
3. Lead Zirconate
4. Cadmium and sulphate
a) 1,2 and 4
b) 1,3and4
c) 1,2and 3
d) 2,3and 4
Ans : (c)

17. Piezo-electric transducers are
a) Passive transducers
b) Inverse transducers
c) Digital transducers
d) Pulse transducers
Ans : (b)

18. Piezo - electric transducers work when we apply _____________ to it.
a) Mechanical force
b) Vibrations
c) Illuminations
d) Heat
Ans : (d)
19. Piezo electric crystal can produce an emf
a) When external mechanical force is applied to i
b) When radiant energy stimulates the crystal
c) When external magnetic field is applied
d) When the junction of two such crystals are heated Ans : (a)

20. The draw backs of strain gauges are
S1: Low fatigue life
S2: They are expensive, brittle and sensitive to temperature
S3: Poor linearity
a) S1 and S2
b) S2 and S3
c) S1 and S3
d) S1 only
Ans : (b)

21. LVDT windings are wound on
a) Steel sheets
b) Aluminium
c) Ferrite
d) Copper
Ans : (c)

22. The size of air cored transducers in comparison to the iron core parts is
a) Smaller
b) Larger
c) Same
d) Unpredictable
Ans : (b)

23. The principle of operation of LVDT is based on the variation of
a) Self inductance
b) Mutual inductance
c) Reluctance
d) Permanence
Ans : (b)

24. LVDT is an/a ___________ transducer
a) Magneto-strict ion
b) Inductive
c) Resistive
d) Eddy current
Ans : (d)

25. Which of the following can be measured with the help of piezo electric crystal?
a) Force
b) Velocity
c) Sound
d) Pressure
Ans : (a)

26. S1: Transducer is a device which converts physical into electrical quantity
S2: Transducer is also called as sensor.
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans (b)


27. In a LVDT, the two secondary voltages
a) Are independent of the core position
b) Vary unequally depending on the core position
c) Vary equally depending on the core position
d) Are always in phase quadrature
Ans : (b)

28. Capacitive transducers are normally employed for___________ measurements
a) Static
b) Dynamic
c) Transient
d) Both static and dynamic
Ans : (b)

29. Match the following
1. EEG A. Diagnostic tool for heart alignment
2. ECG B. Diagnostic tool for brain alignment
3. Sphygmo-manometer C. Instrument used for measuring blood pressure
4. Stethoscope D. instrument used to hear pulse/heart beat
a) 1- B, 2 - A, 3 - C, 4 - D
b) 1 - B, 2 - A, 3 - D, 4 - C
c) 1- C, 2 - A, 3 - B, 4 - D
d) 1 - A, 2 - B, 3 - C, 4 - D
Ans : (a)

30. Pick the correct statement regarding functions of a transducer
S1: Sense the magnitude, change in & / or frequency of same measurand
S2: To provide electrical output that furnishes accurate, quantitative data about the measurand
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans : (c)

electronics MCQ Objective solved questions for IES

electronics MCQ Objective solved questions for IES
Electronics engineering objective type questions
Solved Multiple Choice Questions Electronics engineering For SAIL GAIL ONGC IES
Engg Multiple Choice Questions: IES ELECTRONICS

1 Selenium photo cells are sensitive to the visible spectrum of
a) 400 – 700 mµ
b) 350 – 700 mµ
c) 300 – 700 mµ
d) 450 – 700 mµ
Ans : (c)


2 Respiratory volume is measured using
a) Myograph
b) Pneumograph
c) Spiro meter
d) Goniometer
Ans : (b)

3. Match the following
1. Sensitivity A. Ability to detect very small change
2. Stability B. Ability to produce constant output
3. Precision C. Measure of reproducibility
4. Accuracy D. Closeness to true value
a) 1- B, 2 - A, 3 - C, 4 - D
b) 1 - B, 2 - A, 3 - D, 4 - C
c) 1- C, 2 - A, 3 - B, 4 - D
d) 1 - A, 2 - B, 3 - C, 4 - D
Ans : (d)
4. Piezo electric materials have ___________ resistivity
a) Zero
b) Infinite
c) Finite
d) Null
Ans : (c)
5Dummy gauge is mounted on the opposite arm of the active gauge to cancel output differentials due to
a) Temperature variation of resistance
b) Pressure variation of resistance
c) pH concentration variation
d) Change in blood flow
Ans : (a)

6. For fiber optic sensors,
a) Single mode transmission is used
b) Multimode transmission is used
c) Both single mode and multimode transmission is used
d) Transmission is not used

Ans (a)

7 One of the combination of materials used for optical fibers are ___________
a) Copper core and glass cladding
b) Glass core and aluminum cladding
c) Glass core and plastic cladding
d) Plastic core and glass cladding
Ans (c)

8 The optical sensors may be classified as _________
a) Intensity and intrinsic types
b) Interferometric and extrinsic types
c) Intensity or intrinsic type and Interferometric or extrinsic types
d) Only extrinsic type
Ans (c)






9.The gauge factor is given as
a) ∆R/R
∆I/I
b) ∆I/I
∆R/R
c) ∆R/R
∆D/D
d) ∆D/D
∆R/R
Ans : (a)

10. The gauge factor G and the poisons ratio µ are related as
a) G = 1+µ
b) G = µ
c) G = 1+2µ
d) G = 1+µ /2
Ans : (a)


11. In variable capacitance transducer, C=
a) kξo/Ad
b) kξoA/d
c) kξod/A
d) Aξo/kd
Ans : (b)



12. Inductance of a coil is given by L =
a) N2R
b) N2 + R
c) N2 - R
d) N2 / R
Ans : (d)





13 ______________ is called as linistor when it provides a linear change in resistance with respect to temperature
a) Thermistor
b) Thermocouple
c) Thermometer
d) Thermo resistive transducer
Ans : (a)


14.. An operational amplifier is a
S1: Direct coupled high gain amplifier
S2: Device to perform linear operation
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans : (c)

15. The input impedance of the operational amplifier is
a) Infinite
b) Zero
c) Very high but not infinite
d) Very small
Ans : (c)

16. Power supply rejection ratio of an OPAMP should be
a) Ideally unity
b) Zero
c) As small as possible
d) As large as possible
Ans : (d)




17. The ideal value of CMRR is
a) 1
b) 0
c) -∞
d) ∞
Ans : (d)

18. To get very high input impedance ________________ is also used as an isolation amplifier.
a) Boost strapping circuit
b) Darlington pair
c) Push pull circuit
d) Emitter follower
Ans : (a)

19. Carrier amplifiers are characterized by
a) Low gain
b) Medium gain
c) High gain
d) Drift
Ans : (c)

20. DC amplifiers are generally
S1: Negative feedback type
S2: Positive feedback type
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans : (a)

21. Isolation amplifiers are commonly used for providing protection against
a) Grounding
b) Leakage currents
c) Stray field
d) Shock

Ans : (b)
22 __________is the recording of the bio potentials generated by the movement of the eye ball.
a) Electro oculograph
b) Electro retinograph
c) Apexcardiograph
d) Ballistograph
Ans : (b)




23. The heart sounds are recorded by
a) Electrocardiography
b) Endoscope
c) Phono cardiograph
d) Angio cardiograph
Ans : (c)

24.. Type of laser used in photo chemical process is
a) CO2
b) Nd-YAG
c) He-Ne
d) Excimer lasers
Ans : (c)

25.. MRI makes use of the _____ region of the electromagnetic spectra to provide an image.
a) Ultra Violet
b) Radio Frequency
c) Infra Red
d) Ultra High frequency
Ans : (b)

26.. (A) Spin Density – (1) Signal is proportional to no. of nuclei present
(B) Spin lattice – (2) Longitudinal relaxation time
(C)Spin-spin – (3) Transverse relaxation time
a) A-1, B-2, C-3
b) A-2,B-3,C-1
c) A-3,B-1,C-2
d) A-2,B-1,C-3
Ans : (a)

27.. (A) A mode – (1) Reflected echoes are depicted as dots
(B) B mode – (2) unidirectional graphic representation
(C)M /T-M mode – (3) Reflected echoes are depicted as vertical spikes
a) A-1, B-2, C-3
b) A-2,B-3,C-1
c) A-3,B-1,C-2
d) A-2,B-1,C-3
Ans : (c)





28.. Ultra sound is a form of energy which consists of
S1: Mechanical vibrations of high frequency
S2: Elecrical vibrations of high frequency
a) S1 is true
b) S2 is true
c) S1 and S2 are true
d) S1 and S2 are false
Ans : (a)

29.. CT scanner is highly helpful in
a) Bone tumours
b) Thorax scanning
c) Neck scanning
d) Brain scanning
Ans : (d)

30. The first medical application of LASER was in
a) Gastrology
b) Bronchoscopy
c) Opthalmology
d) Cardiography
Ans : (c)

31. In D.C. defibrillator, a pulse width of 5 to 10 msec duration is generated by means of
a) Astable multivibrator
b) Monostable multivibrator
c) IC 555
d) Capacitor discharge
Ans : (d)

32.. Micro shock may occur due to flow of
a) 1 ampere current across body surface
b) Few milli ampere current across the cardiac muscles
c) 5 milli ampere current across the body surface for 1 minute
d) 5 milli ampere current across the body surface
Ans : (b)

33. The use of super conducting magnets in MRI is to obtain
a) Signals from surface tissue
b) High R.F. field
c) High strength gradient fields
d) High strength magnetic fields
Ans ; (d)