DFCCIL electronics and electrical questions

Dedicated Freight Corridor Corporation of India (DFCCIL

Dedicated Freight Corridor Corporation of India (DFCCIL)
1. What does LED stand for?
Light Emitting Display
Low Energy Display
Light Emitting Diode-Answer
Light Emitting Detector

2. Name the three leads of a common transistor
Collector Bias Omitter
Base Collector Case
Emitter Collector Bias
Collector Base Emitter-Answer

3. Connecting a lead from the negative to the positive of a battery will produce:
A high resistance circuit
A short circuit-Answer
A low current path
An open circuit

4. What is the approximate characteristic voltage that develops across a red LED?

1.7v-Answer
3.4v
0.6v
5v

5. If two resistors are placed in series, is the final resistance:
Higher-Answer
Lower
he same
Cannot be determined

6. Which is not a "common" value of resistance:
2k7
1M8
330R
4k4-Answer

7. If a small value of capacitance is connected in parallel with a large value, the combined capacitance will be:
The same
Higher-Answer
Lower

8. If the voltage on the base of a transistor increases, does it:
Turn on
Turn off
Not enough information-Answer
Remain the same

9. The resistor identified in brown is called the:

Base Bias Resistor
Load Resistor
Emitter Feedback Resistor
Bypass Resistor-Answer

10. A 100n capacitor in parallel with 10n produces:
90n
100n
110n-Answer
Cannot be determined

11. A resistor with colour bands: red-red-red-gold, has the value: 
22k 5%
2k2 5%-Answer
220R 5% 
22R 5%

12. The lead marked with the arrow is:

The Collector
The Base
The Emitter-Answer
The case

13. A 10k resistor in parallel with 10k produces:
10k
5k-Answer
20k
Cannot be determined

14. The symbol is: 

NPN Transistor
PNP Transistor-Answer
Photo Transistor
Field Effect Transistor

15. Two 3v batteries are connected as shown. 
The output voltage is: 

3v
0v-Answer
6v

16. 4 resistors in ascending order are: 
22R 270k 2k2 1M
4k7 10k 47R 330k
3R3 4R7 22R 5k6-Answer
100R 10k 1M 3k3

17. The closest value for this combination is: 

4k7
2k3-Answer
9k4

18. This stage is called:
     

Common Base
Common Collector
Common Emitter-Answer
Emitter Follower



19. The four symbols are: 
Capacitor, Microphone, Potentiometer, Electrolytic-Answer
Electrolytic, Microphone, Resistor, Capacitor 
Capacitor, Piezo, Resistor, Electrolytic
Electrolytic, Coil, Resistor, Capacitor

20. The value of the combination is: 

100n
200n-Answer
50n

21. The resistor marked in red is: 

Base Bias Resistor-Answer
Load Resistor
Emitter Feedback Resistor
Bypass Resistor

22. A resistor and capacitor in series is called a:

Pulse Circuit
Timing Circuit/Delay Circuit-Answer
Oscillator Circuit/Frequency Circuit
Schmitt Circuit

23. A red-red-red-gold resistor in series with an orange-orange-orange-gold resistor produces:

5k5
35,200 ohms-Answer
55k
None of the above

24. Name the 4 components: 

Photo transistor, switch, capacitor, coil
Transistor, mercury switch, piezo, coil 
Photo transistor, reed switch, piezo, coil
Photo darlington transistor, reed switch, piezo, coil-Answer

25. To obtain a higher value of resistance, resistors are  connected in:

Reverse
Forward
Parallel
Series-Answer

26. A capacitor and coil in parallel is called:

A Tuned Circuit-Answer
A Timing Circuit
A Delay Circuit
A Schmitt Circuit


27. When the base is raised, the emitter will:

Rise-Answer
Fall
Remain Fixed
Oscillate

28. What is 1,000p?

0.01n-Answer
0.0001u
0.1n
1n

29. The current in a circuit is 45mA. This is:
0.045Amp-Answer
0.00045A
0.0045A
0.45A

30. A 100n capacitor can be expressed as:
0.1u u = microfarad-Answer
0.01u
0.001u
none of the above

31. 1mA is equal to:
0.001A-Answer
0.00001A
0.01A
0.1A

32. 1,200mV is equal to:
12v
1.2v-Answer
0.12v
0.0012v

33. If a 10k resistor is placed across a 10v supply, the current will be:
10mA
1mA-Answer
0.01mA
0.1mA

34. This arrangement is called:

Common Emitter
Common Collector/Emitter Follower-Answer
Common Base

35. Identify the correctly connected LED:

A
B-Answer
C
D

36. Identify the correct statement:

The cathode lead is longer. It goes to the negative rail
The cathode lead is shorter. It goes to the negative rail-Answer
The cathode lead is shorter. It goes to the positive rail
The cathode lead is longer. It goes to the positive rail

37. The current requirement of a LED is:
1.7mA
25mA
Between 3 and 35mA-Answer
65mA

38. The signal at the collector will be . .

.
Answer inverted

39. The purpose of the capacitor:

To pass AC on the input to the base
To allow the transistor to self-bias
Block DC from the input line-Answer
To allow the stage to operate

40. The direction of conduction for a diode is:

answer-A

41. A DC voltage . . .
rises and falls
is a sinewave
remains constant-Answer
is an audio waveform

42. A CRO is a
Cathode Ray Oscillator
Cathode Ray Oscilloscope-Answer
Capacitor-Resistor Oscillator
Capacitor-Resistor Output

43. These jargon terms mean: (Jargon = language peculiar to a 'mickey' 'electro' 'cap' 'puff'; trade)

mighty, electronic, capper, picofarad
microfarad, electronic, capacitor, picofarad
microfarad, electrolytic, capacitor, picofarad-Answer
microfarad, electrolyte, capping, blow

44. The tolerance bands: gold; silver; brown, represent:
10%, 5%, 1%
5%, 10%, 2%
5%, 10%, 1%-Answer
10%, 5%, 2%

45. 223 on a capacitor represents:
0.022u u = microfarad-Answer
22n n = nanofarad
22,000p p = picofarad
All of the above

46. Arrange these in ascending order: n, p, u  
p, u, n, 
n, u, p
p, n, u-Answer

47. Name this symbol:

A buffer
A NOR gate
A NAND gate
A Schmitt Trigger-Answer

48. The number "104" on a capacitor indicates:
0.1u
100n-Answer
1n
10n

49. What is the multimeter detecting:

The output voltage of the Schmitt Trigger
The delay across the capacitor
The voltage across the capacitor-Answer
The current through the capacitor

50. For the XOR gate, what is the output when both inputs are HIGH:

HIGH
LOW-Answer
Can be HIGH or LOW
Cannot be determined