Practice Set on Diploma Electronics Engineering

1. Find the wrong statement: specific heat of a material is
(a) Constant
(b) heat capacity per unit mass
(c) extrinsic property
(d) of units as Joule/Kg-K

2. Metals have thermal conductivities in the range of
(a) < 1
(b) 1-5
(c) 5-25
(d) 20-400

3. For carbon resistors what is the color for 5?
(a) Green
(b) Black
(c) Orange
(d) gray

4. The four stripes of a resistor are yellow-violet-orange-gold. The value of the resistance should be
(a) 470Ω ± 5%
(b) 47KΩ ± 5%
(c) 47MΩ ± 5%
(d) 47KΩ ± 10%

5. In a nickel-cadmium-alkali cell the electrolyte is
(a) sulphur acid
(b) potassium hydroxide
(c) zinc chloride
(d) ammonium chloride

6. Resistivity of a wire depends on
(a) Length
(b) Material
(c) cross sectional area
(d) none of these

7. Resistance of a wire is r ohms. The wire is stretched to double its length then its resistance in ohms is
(a) r/2
(b) 4r
(c) 2r
(d) r/4

8. The mass of a proton is roughly how many times the mass of an electron?
(a) 184,000
(b) 18,400
(c) 1,840
(d) 184

9. Two bulbs marked 200 watt – 250 Volts and 100 watt – 250 Volts are connected in series to 250 Volts supply. Power consumed in circuit is
(a) 33 watt
(b) 66.667watt
(c) 100 watt
(d) 300 watt

10. When P=power, V= voltage, I= current, R=resistance and G= conductance. Which of the following relation is incorrect?
(a) V = √ (PR)
(b) P = V2G
(c) G = P/I2
(d) I = √(P/R)

11. The unit of electrical conductivity is
(a) mho/meter
(b) mho/m2
(c) ohm/m
(d) ohm/m2

12. The element of electric heater is made of
(a) Copper
(b) Steel
(c) Carbon
(d) nichrome

13. Which of the following materials is not used as a fuse material?
(a) Silver
(b) Copper
(c) aluminium
(d) carbon

14. Materials which can store electrical energy are called
(a) magnetic materials
(b) semi-conductors
(c) dielectric materials
(d) super conductors

15. Which method can be used for absolute measurement of resistance?
(a) Ohm’s Law method
(b) Wheatstone bridge method
(c) Raleigh method
(d) Lorentz method

16. The wave representation of electron
(a) is confirmed by Bragg’s Law
(b) satisfies Uncertainty principle
(c) represents lowest energy
(d) was suggested by Rutherford

17. Ionic bonding in solids depends primarily on
(a) Van der Waals forces
(b) electrical dipoles
(c) sharing of electrons
(d) transfer of electrons

18. Which of the following materials does not have covalent bonds?
(a) Metals
(b) Diamond
(c) organic polymers
(d) silicon

19. The electrostatic nature of ionic bond makes it
(a) Directional
(b) non-directional
(c) weak
(d) related to group IV element

20. The crystal structure of most of the common metal is
(a) Hexagonal
(b) Cubic
(c) orthogonal
(d) none of these

21. Silica is said to be polymorphic because it
(a) consists of multitude of tiny crystals
(b) is found in many shapes
(c) has mixed bonding
(d) displays allotropic forms

22. The miller indices are the same for
(a) perpendicular planes
(b) crystal planes
(c) parallel planes
(d) 3 crystallographic axes

23. Dielectric strength of impregnated paper is
(a) 40-50 KV/cm
(b) 200- 300 KV/cm
(c) 500-600 KV/cm
(d) 800-900 KV/cm

24. Which of the following does not constitute a point defect in crystal?
(a) self interstitials
(b) substitutional atoms
(c) slip lines
(d) vacancies

25. Dislocations in material are
(a) point defect
(b) line defect
(c) planner defect
(d) frenkel defect

More Question Set on Electronics Engineering Diploma MCQs from Various Exam

26. The permeability and permittivity of a medium are
(a) independent of each other
(b) related by the velocity of electromagnetic wave
(c) related by the Boltzmann’s constant
(d) None of the above

27. An element can form a strongly magnetic solid only if its atoms have
(a) an incomplete valence shell
(b) an incomplete inner shell
(c) a vacant inner shell
(d) none of the above

28. Which of the following expression states Gibb’s phase rule?
(a) F = C-P+1
(b) F = C-P+2
(c) F = C-P+3
(d) F = C+P-3

29. Magnetic recording tape is most commonly made from
(a) small particles of iron
(b) silicon iron
(c) ferric oxide
(d) ferrous oxide

30. Stainless steel are alloys of
(a) iron and nickel
(b) iron, chromium and nickel
(c) iron, chromium and molybdenum
(d) none of these

31. The number of atoms per unit cell in the F.C.C. structure is
(a) 2
(b) 4
(c) 14
(d) 16

32. Which of the following processes are used to harden steel?
(a) normalizing
(b) carburizing
(c) annealing
(d) all of these

33. Eutectoid transformation in an alloy is a reaction of which type?
(a) Solid ↔ liquid
(b) liquid ↔ liquid
(c) solid ↔solid
(d) any of these

34. A TTT diagram is useful for predicting the transformation behaviour of
(a) Ferrite
(b) Austenite
(c) martensite
(d) pearlite

35. The main constituent of glass is
(a) SiO2
(b) B2O3
(c) Al2O3
(d) none of these

36. The temperature at which a material becomes a glassy solid is called
(a) melting temperature
(b) recrystallization temperature
(c) glass transition temperature
(d) freezing temperature

37. Polyethylene is produced by
(a) condensation polymerization
(b) addition polymerization
(c) co-polymerization
(d) all of the above

38. Vulcanized rubber
(a) Is produced from trans-polyisoprene
(b) Is alternatively known as neoprene
(c) Contains about 20% sulphur by weight
(d) Is produced from cis-polyisoprene

39. The potential energy of an orbiting electron in any atom is
(a) always +ve
(b) always –ve
(c) sometimes +ve
(d) less than its Kinetic energy

40. An insulator is one whose
(a) valence band is empty
(b) conduction band is full
(c) energy gap between the two band is large
(d) none of these

41. Intrinsic semiconductor are those which
(a) are available locally
(b) are in the purest form
(c) have more electrons than holes
(d) have zero energy gap

42. The depletion region of a P-N junction is one that is depleted of
(a) Atoms
(b) mobile charges
(c) electrons
(d) immobile charges

43. For converting intrinsic semiconductor into N type extrinsic semiconductor, which of the following doping element will not be suitable?
(a) Arsenic
(b) Antimony
(c) Indium
(d) phosphorous

44. At higher forward voltages, a junction diode is likely to
(a) burnout
(b) get saturated
(c) suffer breakdown
(d) become noisy

45. A general purpose diode is more likely to suffer avalanche breakdown rather than zener breakdown because
(a) its leakage current is small
(b) it has strong co-valent bond
(c) it is lightly doped
(d) it has low reverse resistance

46. The turn on voltage of a Ge junction diode is
(a) 0.1 V
(b) 0.3 V
(c) 0.7 V
(d) 1.0 V

47. Zener diode is always used with
(a) forward bias
(b) reverse bias
(c) no bias
(d) all of the above

48. The junction capacitance of a varactor diode is 5pf with a reverse voltage of 4V. If this bias is increased to 16V then the capacitance would become
(a) 20pf
(b) 10pf
(c) 2.5pf
(d) 1.25pf

49. The peak inverse voltage is applied across a diode when it is
(a) On
(b) on a heat sink
(c) reverse biased
(d) forward biased

50. When bias is applied to a varicap diode is increased, its capacitance
(a) Decreases
(b) Increases
(c) remains constant
(d) increases than decreases