PCB Designing multiple choice questions

 PCB Designing

1. Which phenomenon is not reduced by the circuit paths of lowest impedances especially provided by power and return planes for shielding purposes?
a) Radiation
b) Convection
c) Noise
d) Crosstalk
Answer: Convection
2. High current circuits are purposely located or placed near the edge of PCB in accordance to the supply lines for  ________
a) Removal of heat
b) Isolation of stray current
c) Reduction of path length
d) All of the above
Answer: Removal of heat
3. Which among the below stated soldering methods is also renowned as 'High Frequency Resistance Soldering'?
a) Iron Soldering
b) Furnace Soldering
c) Torch Soldering
d) Electrical Soldering
Answer: Electrical Soldering
4. Which among the below mentioned approaches belongs to the category of In-circuit Testing?
a) Impedance Testing
b) Component Testing
c) Apply Signal and check output
d) All of the above
Answer: All of the above
5. Which type of solderability testing is carried out for the generation of solder sample due to immersion of wire or sheet metal specimen in a bath of molten solder?
a) Solder Bath Testing
b) Meniscus Rise Testing
c) Solder Iron Testing
d) None of the above
Answer: Meniscus Rise Testing
6. What is/are the necessity/ies to provide guarding to precision differential amplifiers?
a) To increase leakage resistance
b) To reduce capacitance between signal conductors & ground
c) Both a and b
d) None of the above
Answer: Both a and b
7. Which among the below mentioned assertions is not a way of cross-talk reduction while designing digital PCBs?
a) Decrease in the distance between conductors
b) Shielding of clock lines with guard strips
c) Reduction in the loop area of circuits
d) Avoid running of parallel traces for longer distances especially for asynchronous signals
Answer: Decrease in the distance between conductors
8. Which among the below mentioned packages does not belong to the category of 'Small Outline Package'?
a) SO
b) SOP
c) SOT
d) SON
Answer: SON
9. Which among the below specified assertions is not a grounding consideration associated with ADC as well as DAC?
a) Analog side to analog ground
b) Digital side to digital ground
c) Use of separate power supply and connection of their ground leads to single point reference
d) Reduction of inductive loop area between power and return traces
Answer: Reduction of inductive loop area between power and return traces
10. Which among the below stated devices/equipments are preferred for elimination of  ground and supply line noise especially in TTL/CMOS / ECL PCB designing?
a) Coupling capacitor
b) Decoupling capacitor
c) Snubber circuits
d) All of the above
Answer: Decoupling capacitor
11. Which among the below specified condition is precise in the crosstalk verification mechanism using logic flow in opposite direction with the limit of avoiding dangerous interference in digital PCB designing?
a) Zeven > Zodd
b) Zodd ≥ 0.5 Zeven
c) Zodd ≥ 0.8 Zeven
d) Zodd = Zeven
Answer: Zodd ≥ 0.8 Zeven
12. Which terminology of PCB represents a thin photo-sensitive polymer by supporting photographic pattern of single traces or IC pads for etching?
a) Prepreg
b) Etching
c) Photo-resist
d) Solder mask
Answer: Photo-resist
13. Which problems are about to occur if PCB is not designed properly in a confined manner for digital circuits?  
A. Diffraction
B. Refraction
C. Ground & Supply-line Noise
D. Electromagnetic Interference
a) A & B
b) B & C
c) C & D
d) A, B, C, D
Answer: C & D
14. Which among the following assists in obtaining the desired value of wave impedance in reflection phase while designing digital PCBs?
A. Width of signal lines
B. Distance between signal line and ground line
C. Signal Delays
D. Double Pulsing
a) A & B
b) B & C
c) C & D
d) A, B, C, D
Answer: A & B
15. What should be the resistance of 0.6 mm wide conductor with 15 cm length and 25 μm thickness of standard copper foil? (Assume ρ = 1.7241 x 10-6(at 20° C)
a) 118.2 mΩ
b) 138.2 mΩ
c) 172.4 mΩ
d) 192.4 mΩ
Answer: 172.4 mΩ
16. The actual cost of PCB can be evaluated on the basis of ________
a) PCB size & material
b) Number of layers
c) Vias on PCB
d) All of the above 
Answer: All of the above
17. Which factors contribute to the occurrence of mechanical stress?
a) Resonance
b) Cracked Solder Joints
c) Both a and b
d) None of the above
Answer: Both a and b
18. Which type of PCB requires minimum soldering on component side in order to avoid replacement oriented difficulties?
a) Single-sided PCB
b) Double-sided PCB
c) Both a and b
d) None of the above
Answer: Double-sided PCB
19. What effects can be observed if the separate power and ground planes are provided with large conducting surfaces for better decoupling in PCB layouts?
a) Increase in self-inductance
b) Reduction in self-inductance
c) Stability in self-inductance
d) None of the above
Answer: Reduction in self-inductance


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