Test answers for PCB Design Test 2015

1 Answered Test Questions:

1. Which of the following is not a film used in PCB design?

Answers:

• A copper film

• A polyester film

• A photographic glass

• A tri-acetate film

67 NOT Answered Yet Test Questions:

(hold on, will be updated soon)

2. Which one of the following is not a plating technique?

Answers:

• Immersion plating

• Electroless plating

• Hard plating

• Electroplating

3. The analog and the digital circuit on the same PCB should have _____.

Answers:

• common ground conductor networks

• independent ground conductor networks

• no ground conductor network

• None of the above

4. When two transmission lines are placed close to each other, they are said to be coupled. This coupling can be used to built

Answers:

• band pass filters

• band elimination filters

• directional couplers

• All of the above

5. Etch back is a technique by which ______.

Answers:

• epoxy smear is removed and the exposed glass fibers prepared for copper deposition

• epoxy smear is deposited and the exposed glass fibers prepared for copper removal

• etchants are removed again

• None of the above

6. Parasitic effects influence the working of a PCB.

Answers:

• true

• false

• sometimes true and sometimes false

7. In the layout approach, a 'Puppet' is used for_____.

Answers:

• a diode

• a transistor

• an IC

• any commonly used electronic component

8. For TTL , we require a wave impedance of_____.

Answers:

• 50-100ohm

• 100-150ohm

• 150-200ohm

• 200-250ohm

9. Large values of wave impedance call for _____.

Answers:

• broader signal conductors

• thin signal conductors

• both a and b

10. Screen printing is used in _____.

Answers:

• photo printing

• screen printing

• hand printing

• All of the above

11. Which of the following is not a machine cleaning process for boards?

Answers:

• Sanding

• Water rinse

• Wet brushing

• Scrubbing

12. Which of the following is a design constraint for the design of the flexible PCBs?

Answers:

• Current carrying capacity of the conductors

• Bending

• Contours

• All of the above

13. Self soldering or soldering generally implies that the joining process occurs at temperatures below

Answers:

• 100°c

• 200°c

• 350°c

• 450°c

14. What is hot air leveling used for?

Answers:

• Etching

• PCB finishing

• PCB layout

• PCB artwork

15. A conductor in a printed circuit should be considered a transmission line if its length l (in meters) is

Answers:

• l > Tr/100 nsec ( Tr- rise time of pulse)

• l > 2Tr/100 nsec

• l > Tr/200 nsec

• l > 2Tr/50 nsec

16. Which of the following is not a physical characteristic of a copper clad laminate?

Answers:

• Flame resistance

• Water absorption

• Flexural strength

• Color

17. In fast signal or high – speed logic circuits , the conductors are considered to be _____.

Answers:

• impedances

• transmission lines

• capacitors

• inductors

18. Copper plating is done in multilayer boards to _____.

Answers:

• remove etchants

• remove excess copper

• withstand thermal shock due to soldering

• clean a PCB with chemicals

19. The dielectric constant of any material is also referred to as _____.

Answers:

• permeability

• permittivity

• proximity

• resistivity

20. Which of the following techniques is used in mass soldering?

Answers:

• Dip soldering

• Drag soldering

• Wave soldering

• All of the above

21. Which of the following is a technique for the generation of the circuit pattern on metal core boards?

Answers:

• Substance additive processing

• Additive processing with catalytic adhesive

• Semi-additive processing

• Both a and b

22. By which material is the typical resin/filler laminate of ordinary PCBs replaced in metal core boards?

Answers:

• Sheet metal covered with insulation material

• Cardboard

• Foil with insulation

• None of the above

23. Which of the following is not a solder alloy?

Answers:

• Tin lead

• Tin antimony

• Tin silver

• Iron lead

24. Which of the following is a category of dry film resists?

Answers:

• Solvent developing dry film resists

• Liquid developing dry film resists

• Hand developing dry film resists

• All of the above

25. For the etching process, the temperature should preferably be around

Answers:

• 30°C

• 10°C

• 45°C

• 100°C

26. The volume resistivity of a laminate is given by

Answers:

• R*A / l R- resistance measured

• R*l / A A-area of gourde electrode (cm2)

• A*l / R l-thickness of sample(cm)

• R / A*l

27. A standard hole(0.8mm) in a PCB design is represented by which symbol.

Answers:

• О

• €

• Ө

• β

28. The biggest problem associated with striplines and microstrip lines is the

Answers:

• low attenuation per unit length

• high attenuation per unit length

• low impedance per unit length

• high impedance per unit length

29. Ferric chloride is used in PCB designing as a/an _____.

Answers:

• resist

• etchant

• board cleaner

• a soldering material

30. In which of the following ways can the required quantity of heat for the melting of the solder be supplied?

Answers:

• Iron soldering

• Hot gas soldering

• Radiant heat soldering

• All of the above

31. Which of the following is a base material used in the manufacturing of flexible PCBs?

Answers:

• Epoxy resin

• Polyester foil

• Teflon foil

• All of the above

32. Which of the following is not a basic ingredient of a copper clad laminate?

Answers:

• Filler

• Resin

• Silver foil

• Copper foil

33. Ultra thin copper foil has a range of thickness varying from

Answers:

• 5-10cm

• 5-10mm

• 5-10um

• 5-10nm

34. Current spikes in TTL circuit boards can be eliminated by which technique.

Answers:

• removing the TTL circuit

• replacing transistors with diodes

• using a ground line

• All of the above

35. Which of the following tests is done for quality control for multilayer boards?

Answers:

• Electrical and metallographic test

• Continuity between layers test

• Insulation resistance between layers test

• All of the above

36. The skin-effect losses are sometimes also called

Answers:

• semiconductor losses

• conductor losses

• insulator losses

• None of the above

37. By which material is the transfer of the conductor pattern from the film master on to the copper clad base material done?

Answers:

• Photo printing

• Hand printing

• Screen printing

• Both a and c

38. Removing the resists from the board in photo printing is called

Answers:

• Post backing

• stripping

• touch up

• dyeing

39. Which  size of  rack is used as a standard rack in PCB design?

Answers:

• 18"

• 19"

• 20"

• 21"

40. The microstrip line is derived from a _____.

Answers:

• conductor on the ground

• conductor below the ground

• conductor above the ground

• None of the above

41. Crosstalk is much less dangerous in which of the following.

Answers:

• ECL-ICs

• TTL-ICs

• RTL-ICs

• CMOS -ICs

42. Which of the following can be called multilayer construction?

Answers:

• Clearance holes

• Plated through holes

• Fused tubelets or eyelets

• All of the above

43. On a PCB, the low power part and the high power part have to be spread sufficiently to avoid _____.

Answers:

• capacitive and inductive coupling between power circuits

• crosstalk

• only inductive coupling

• only capacitive coupling

44. To overcome the motorboating effect, we must _____.

Answers:

• do decoupling of power supply conductors with sufficiently large capacitors

• do decoupling of power supply conductors with small capacitors

• not to do any decoupling

45. If a ground line is kept close to a signal line, crosstalk would be _____.

Answers:

• high

• low

• same

46. Which of the following is a type of soldering fluxes?

Answers:

• Corrosive fluxes

• Intermediate fluxes

• Non-corrosive fluxes

• All of the above

47. Under which of the following conditions is a multilayers board used?

Answers:

• Where the overall PCB dimensions and interconnections are not feasible on a double-sided PCB

• Where reduction in electronic equipment weight and volume is the prime concern

• Where decoupling and shielding of the interconnections is important

• All of the above

48. Fabrication of PCBs for microwave use requires

Answers:

• VSWR > 1

• VSWR < 1

• VSWR exactly 1

• VSWR equal to zero

49. The biggest disadvantage of flexible PCBs is that

Answers:

• they can not be used for low frequency applications

• they are not suitable for high frequency applications

• they can be used only in military applications

• they can used only in aerospace applications

50. How much copper surface is reserved on multilayer boards for the solderability test?

Answers:

• 20×70 mm

• 10×50 mm

• 20×70 cm

• 10×50 cm

51. The fundamental principle of electrolysis is understood from

Answers:

• Ampere's law

• Faraday's law

• Ohm's law

• Coulomb's law

52. If  Ohmic losses are neglected, the wave impedance Zw in a homogenous material can be calculated by using the formula.

Answers:

• Zw =(L/C)1/2

• Zw =(2L/C)1/2

• Zw =(2C/L)1/2

• Zw =(C/L)1/2

53. What would be the simplest and most suitable remedy for electro-magnetic coupling between two wires?

Answers:

• To increase the space between two wires

• To increase the lamination between two wires

• To twist the both wires

• To decrease the spacing between two wires

54. It is a common experience of electronic circuit designers that at high frequency{>10 MHz), amplifiers behave as _____.

Answers:

• oscillators

• tuned amplifiers

• feedback amplifiers

• Inverters

55. Under etching can be minimized by keeping the etching time _____.

Answers:

• as short as possible

• as long as possible

• equal to 5 minutes

• equal to 30 seconds

56. Which of the following is a solderability test method?

Answers:

• Solder bath test

• Solder globule test

• Surface tension balance test

• All of the above

57. Which of the following is a coating process for wet film resists?

Answers:

• Flow coating

• Roller coating

• Dip coating

• All of the above

58. Which of the following is a disadvantage of a solder mask?

Answers:

• Less contamination of the solder alloy

• Avoidance of solder bridging

• Its capability with the flux has to be verified before use

• Improved flexural strength

59. In which of the following processes is porosity test done?

Answers:

• Plating

• Etching

• Cleaning

• Film master preparation

60. Which of the following is a characteristic parameter of a photographic material?

Answers:

• Density

• Resolving power

• Exposure latitude

• All of the above

61. The inks used in screen printing are mostly

Answers:

• acid based

• alkali based

• vinyl based

• All of the above

62. Which of the following is a mechanical machining operation on PCBs?

Answers:

• Shearing

• Sawing

• Punching

• All of the above

63. Multiwire boards are used in

Answers:

• the implementation of high density electronic circuits

• the implementation of low density electronic circuits

• the implementation of power electronic circuits

• the implementation of power supply circuits

64. All the processing steps for manufacturing ultra thin foils except ____are  conventional.

Answers:

• drilling

• aluminium foil removal

• fortification

• etching

65. The absolute dimensional accuracy of a film master is determined by

Answers:

• the accuracy of the original artwork

• the dimensional stability of the artwork

• the reduction scale of the artwork to the actual PCB size

• All of the above

66. In the component  code used in the circuit diagram, by which letter, according to ANSI, is an integrated  circuit represented?

Answers:

• I

• C

• U

• T

67. To reduce the skin-effect losses, what is required to be done.

Answers:

• decrease PCB – thickness

• increase PCB thickness

• keep line length large

• None of the above

68. Polymeric materials exhibit a very high resistance to

Answers:

• temperature variations

• pressure

• humidity

• elasticity