In the layout approach, a 'Puppet' is used for___________.
a. a diode
b. a transistor
c. an IC
d. any commonly used electronic component
In which of the following ways can the required quantity of heat for the melting of the solder be supplied?
a. Iron soldering
b. Hot gas soldering
c. Radiant heat soldering
d. All of the above
To overcome the motorboating effect, we must __________.
a. do decoupling of power supply conductors with sufficiently large capacitors
b. do decoupling of power supply conductors with small capacitors
c. not to do any decoupling
On a PCB, the low power part and the high power part have to be spread sufficiently to avoid __________.
a. capacitive and inductive coupling between power circuits
b. crosstalk
c. only inductive coupling
d. only capacitive coupling
Current spikes in TTL circuit boards can be eliminated by which technique.
a. removing the TTL circuit
b. replacing transistors with diodes
c. using a ground line
d. All of the above
Which of the following is a characteristic parameter of a photographic material?
a. Density
b. Resolving power
c. Exposure latitude
d. All of the above
Under which of the following conditions is a multilayers board used?
a. Where the overall PCB dimensions and interconnections are not feasible on a double-sided PCB
b. Where reduction in electronic equipment weight and volume is the prime concern
c. Where decoupling and shielding of the interconnections is important
d. All of the above
Which of the following is a category of dry film resists?
a. Solvent developing dry film resists
b. Liquid developing dry film resists
c. Hand developing dry film resists
d. All of the above
Parasitic effects influence the working of a PCB.
a. true
b. false
c. sometimes true and sometimes false
The dielectric constant of any material is also referred to as _________.
a. permeability
b. permittivity
c. proximity
d. resistivity
The biggest problem associated with striplines and microstrip lines is the
a. low attenuation per unit length
b. high attenuation per unit length
c. low impedance per unit length
d. high impedance per unit length
In which of the following processes is porosity test done?
a. Plating
b. Etching
c. Cleaning
d. Film master preparation
A standard hole(0.8mm) in a PCB design is represented by which symbol.
a. О
b. €
c. Ө
d. β
The volume resistivity of a laminate is given by
a. R*A / l R- resistance measured
b. R*l / A A-area of gourde electrode (cm2)
c. A*l / R l-thickness of sample(cm)
d. R / A*l
The skin-effect losses are sometimes also called
a. semiconductor losses
b. conductor losses
c. insulator losses
d. None of the above
To reduce the skin-effect losses, what is required to be done.
a. decrease PCB – thickness
b. increase PCB thickness
c. keep line length l large
d. None of the above
The biggest disadvantage of flexible PCBs is that
a. they can not be used for low frequency applications
b. they are not suitable for high frequency applications
c. they can be used only in military applications
d. they can used only in aerospace applications
Which of the following is a base material used in the manufacturing of flexible PCBs?
a. Epoxy resin
b. Polyester foil
c. Teflon foil
d. All of the above
Which of the following is a solderability test method?
a. Solder bath test
b. Solder globule test
c. Surface tension balance test
d. All of the above
What is hot air leveling used for?
a. Etching
b. PCB finishing
c. PCB layout
d. PCB artwork
If Ohmic losses are neglected, the wave impedance Zw in a homogenous material can be calculated by using the formula.
a. Zw =(L/C)1/2
b. Zw =(2L/C)1/2
c. Zw =(2C/L)1/2
d. Zw =(C/L)1/2
Which one of the following is not a plating technique?
a. Immersion plating
b. Electroless plating
c. Hard plating
d. Electroplating
The fundamental principle of electrolysis is understood from
a. Ampere's law
b. Faraday's law
c. Ohm's law
d. Coulomb's law
Which of the following is a disadvantage of a solder mask?
a. Less contamination of the solder alloy
b. Avoidance of solder bridging
c. Its capability with the flux has to be verified before use
d. Improved flexural strength
Which of the following tests is done for quality control for multilayer boards?
a. Electrical and metallographic test
b. Continuity between layers test
c. Insulation resistance between layers test
d. All of the above
Polymeric materials exhibit a very high resistance to
a. temperature variations
b. pressure
c. humidity
d. elasticity
Fabrication of PCBs for microwave use requires
a. VSWR > 1
b. VSWR < 1
c. VSWR exactly 1
d. VSWR equal to zero
For multilayer boards, the thickness of a board must be between
a. 1.4 and 1.8 cm
b. 1.4 and 1.8 mm
c. 1.4 and 1.8 µm
d. 2.8 and 3.6 mm
Multiwire boards are used in
a. the implementation of high density electronic circuits
b. the implementation of low density electronic circuits
c. the implementation of power electronic circuits
d. the implementation of power supply circuits
A conductor in a printed circuit should be considered a transmission line if its length l (in meters) is
a. l > Tr/100 nsec ( Tr- rise time of pulse)
b. l > 2Tr/100 nsec
c. l > Tr/200 nsec
d. l > 2Tr/50 nsec
If a ground line is kept close to a signal line, crosstalk would be __________.
a. high
b. low
c. same
Self soldering or soldering generally implies that the joining process occurs at temperatures below
a. 100°c
b. 200°c
c. 350°c
d. 450°c
Which of the following is not a film used in PCB design?
a. A copper film
b. A polyester film
c. A photographic glass
d. A tri-acetate film
By which material is the typical resin/filler laminate of ordinary PCBs replaced in metal core boards?
a. Sheet metal covered with insulation material
b. Cardboard
c. Foil with insulation
d. None of the above
Which size of rack is used as a standard rack in PCB design?
a. 18"
b. 19"
c. 20"
d. 21"
The microstrip line is derived from a __________.
a. conductor on the ground
b. conductor below the ground
c. conductor above the ground
d. None of the above
Which of the following is a design constraint for the design of the flexible PCBs?
a. Current carrying capacity of the conductors
b. Bending
c. Contours
d. All of the above
When two transmission lines are placed close to each other, they are said to be coupled. This coupling can be used to built
a. band pass filters
b. band elimination filters
c. directional couplers
d. All of the above
All the processing steps for manufacturing ultra thin foils except _________are conventional.
a. drilling
b. aluminium foil removal
c. fortification
d. etching
Removing the resists from the board in photo printing is called
a. Post backing
b. stripping
c. touch up
d. dyeing
The absolute dimensional accuracy of a film master is determined by
a. the accuracy of the original artwork
b. the dimensional stability of the artwork
c. the reduction scale of the artwork to the actual PCB size
d. All of the above
In the component code used in the circuit diagram, by which letter, according to ANSI, is an integrated circuit represented?
a. I
b. C
c. U
d. T
Screen printing is used in _________.
a. photo printing
b. screen printing
c. hand printing
d. All of the above
It is a common experience of electronic circuit designers that at high frequency{>10 MHz), amplifiers behave as __________.
a. oscillators
b. tuned amplifiers
c. feedback amplifiers
d. Inverters
By which material is the transfer of the conductor pattern from the film master on to the copper clad base material done?
a. Photo printing
b. Hand printing
c. Screen printing
d. Both a and c
What would be the simplest and most suitable remedy for electro-magnetic coupling between two wires?
a. To increase the space between two wires
b. To increase the lamination between two wires
c. To twist the both wires
d. To decrease the spacing between two wires
Which of the following is a technique for the generation of the circuit pattern on metal core boards?
a. Substance additive processing
b. Additive processing with catalytic adhesive
c. Semi-additive processing
d. Both a and b
Ferric chloride is used in PCB designing as a/an __________.
a. resist
b. etchant
c. board cleaner
d. a soldering material
Which of the following is not a basic ingredient of a copper clad laminate?
a. Filler
b. Resin
c. Silver foil
d. Copper foil
Etch back is a technique by which __________.
a. epoxy smear is removed and the exposed glass fibers prepared for copper deposition
b. epoxy smear is deposited and the exposed glass fibers prepared for copper removal
c. etchants are removed again
d. None of the above
For TTL , we require a wave impedance of__________.
a. 50-100ohm
b. 100-150ohm
c. 150-200ohm
d. 200-250ohm
Fabrication of PCBs for microwave use requires
a. VSWR > 1
b. VSWR < 1
c. VSWR exactly 1
d. VSWR equal to zero
The microstrip line is derived from a _________.
a. conductor on the ground
b. conductor below the ground
c. conductor above the ground
d. None of the above
Copper plating is done in multilayer boards to ________.
a. remove etchants
b. remove excess copper
c. withstand thermal shock due to soldering
d. clean a PCB with chemicals
Which of the following is not a machine cleaning process for boards?
a. Sanding
b. Water rinse
c. Wet brushing
d. Scrubbing
Which of the following techniques is used in mass soldering?
a. Dip soldering
b. Drag soldering
c. Wave soldering
d. All of the above
The inks used in screen printing are mostly
a. acid based
b. alkali based
c. vinyl based
d. All of the above
In fast signal or high – speed logic circuits , the conductors are considered to be _________.
a. impedances
b. transmission lines
c. capacitors
d. inductors
Which of the following is a coating process for wet film resists?
a. Flow coating
b. Roller coating
c. Dip coating
d. All of the above
How much copper surface is reserved on multilayer boards for the solderability test?
a. 20×70 mm
b. 10×50 mm
c. 20×70 cm
d. 10×50 cm
A conductor in a printed circuit should be considered a transmission line if its length l (in meters) is
a. l > Tr/100 nsec ( Tr- rise time of pulse)
b. l > 2Tr/100 nsec
c. l > Tr/200 nsec
d. l > 2Tr/50 nsec
Which of the following can be called multilayer construction?
a. Clearance holes
b. Plated through holes
c. Fused tubelets or eyelets
d. All of the above
Crosstalk is much less dangerous in which of the following.
a. ECL-ICs
b. TTL-ICs
c. RTL-ICs
d. CMOS –Ics
Which of the following is not a physical characteristic of a copper clad laminate?
a. Flame resistance
b. Water absorption
c. Flexural strength
d. Color
The analog and the digital circuit on the same PCB should have _________.
a. common ground conductor networks
b. independent ground conductor networks
c. no ground conductor network
d. None of the above
Which of the following is not a solder alloy?
a. Tin lead
b. Tin antimony
c. Tin silver
d. Iron lead
Large values of wave impedance call for __________.
a. broader signal conductors
b. thin signal conductors
c. both a and b
For the etching process, the temperature should preferably be around
a. 30°C
b. 10°C
c. 45°C
d. 100°C
Under etching can be minimized by keeping the etching time __________.
a. as short as possible
b. as long as possible
c. equal to 5 minutes
d. equal to 30 seconds