Wednesday, 26 February 2014

TEST YOUR BASIC ELECTRONICS KNOWLEDGE (50 MCQ)

Electronics within you!!   
Note:    1. ALL QUESTIONS ARE COMPULSARY .                                                      maximum marks:100
2.NO Negative Marking            3.Each Question Carries 2 Marks 
Name:                                         rollno:                                  branch:                     year:
1. Which is not a "common" value of resistance:
a)2k7     b)4k4     c)1m8        d)330R
http://www.talkingelectronics.com/images/50-Q's/50-Qs-19.gif3. The four symbols are:



a)      Capacitor, Microphone, Potentiometer, Electrolytic
b)      Electrolytic, Microphone, Resistor, Capacitor 
c)      Capacitor, Piezo, Resistor, Electrolytic
d)     Electrolytic, Coil, Resistor, Capacitor
5. 223 on a capacitor represents:
a) 0.022u     u = microfarad
b) 220n          n = nanofarad
c) 22,000p    p = picofarad
 d) All of the above
7. Identify the correctly connected LED:
http://www.talkingelectronics.com/images/50-Q's/50-Qs-35.gifa)A     b)B    c)C     d)D
9. The number 0000(ignore carry) would appear just immediately after
(
a) FFFF (hex)   (b) 1111 (binary)   (c) 7777 (octal)  (d) All of the above.
11.what is the frequency of a clock waveform if the period of the wave form is 1.5 us?
a)  8khz  b)0.8 khz  c)  0.8 mhz   d)8mhz
13.The .................ensures the only one IC is active at a time to avoid a conflict caused by two IC’s writing different data to the same bus.
a)Control bus            b) control instructions
c)Address decoder    d)CPU 
15.A basic multiplexer can be demonstrated through the use of a
a)Single pole relay        b) DPDT Switch
c)Rotatory Switch          d)Linear stepper
17.It is required to construct a counter to count upto 100(decimal). The minimum number of flipflops
required to construct the counter is
(A) 8   (B) (C) 6   (D) 5

18.As a general rule for a stable Flip-Flop triggering,the clock pulse rise and fall times must be:
a)very long
b) very short
c)at a maximum value to enable the input control signals to stabilize.
d)of no consequence.

19.What type of circuit is used at the interface point of an output port in the microprocessor?
a)decoder   b)latch    c)tri –State Buffer  d)none

21.The input/output relationship of the common –collector and common-base amplifiers is:
a) 270 degree  b)180 degree  c)90 degree d)0 degree

23.The voltage where current may start to flow in a reverse-biased pn junction is called the
a) breakdown voltage      b)barrier potential
c)forward voltage             d)biasing voltage

25. 4 resistors in ascending order are: 
a) 22R   270k   2k2   1M    b) 4k7   10k   47R   330k
c) 3R3   4R7   22R   5k6     d) 100R   10k   1M   3k3
 http://www.talkingelectronics.com/images/50-Q's/50-Qs-22.gif27. The control terminal (pin5) of 555 timer IC is normally connected to ground through a capacitor
(~ 0.01μF). This is to
(A) protect the IC from inadvertent application of high voltage
(B) prevent false triggering by noise coupled onto the pin
(C) convert the trigger input to sharp pulse by differentiation
(D) suppress any negative triggering pulse
32.in 8051 microcontroller The contents of the accumulator after this operation
MOV A,#0BH
ANL A,#2CH
will be

a) 11010111        b) 11011010
c) 00001000        d) 00101000
36. channel current is reduces on application of a more positive voltage to the GATE of the
depletion mode n-channel MOSFET (true/false)

37.. Which of the following effects can be caused by a rise in temperature
a. Increase in MOSFET current (IDS)                    b. decrease and then Increase in BJT current (IC)
c. Decrease in MOSFET current (IDS)                   d. increase and then Decrease in BJT current (IC)

38.

This figure is a schematic representation of a/an:
A. differential amplifier.                                      B. inverting amplifier.
C. noninverting amplifier.                                   D. voltage follower.
41.  A red-red-red-gold resistor in series with an
      orange-orange-orange-gold resistor produces:

5k5    35,200 ohms    55k         None of the above
43. The signal at the collector will be . . . with the base.
 Inverted . . .
 In-phase . .        .
C)no output 
                         d)none of these



44.What does ‘0L’or ‘1’ on a digital multimeter stands for??
A:  A Open Circuit  B: A Closed Circuit 
C: Inductance   D: None of these
45. What value does hFE on a  digital multimeter represent?
A: Voltage Gain               B: Current  Gain     C: ‘Beta’ value of the transistor
D: ‘alpha’ value of the transistor
46. On the transistor chip BC 547,what  does B stands for?
A: A silicon made transistor        
 B: A germanium made transistor
C: A High Power Transistor      
  D: A Low frequency Transistor
49. In an intrinsic semiconductor, the Fermi-level is
(A) closer to the valence band   (B) midway between conduction and valence band
(C) closer to the conduction band   (D) within the valence band






2. The resistor identified in brown is called the:   
http://www.talkingelectronics.com/images/50-Q's/50-Qs-9.gif  a)Base bias resistor
 b)Load resistor

c)Emmiter feedback resistor

d)Bypass Resistor

http://www.talkingelectronics.com/images/50-Q's/50-Qs-39.gif4. The purpose of the capacitor:
a) To pass AC on the input to the base.
b) To  allow the transistor to self-bias
c) Block DC from the input line
d) To allow the stage to operate
http://www.talkingelectronics.com/images/50-Q's/50-Qs-26.gif6.  A capacitor and coil in parallel is called:
a)Tuned circuit
b)A Timing circuit
c)A delay circuit
d)A Schmit circuit

8. What is the octal equivalent of the binary number:
10111101
A: 675   B: 275   C:  572  D:  573
10.The following waveform pattern is for a(n) ________.
http://www.indiabix.com/_files/images/digital-electronics/digital-fundamentals/mcq5_02300.gif 
a)2 input AND gate   b)2 input OR gate
c)Exclusive-OR gate   d)none of these
12.In a 16-bit microprocessor, words are stored in two consecutive memory locations. The entire word can be read in one operation provided the first
(a) word is even   (b) word is odd
 (c) memory location is odd  (d) memory address is even
14.The technique of assigning a memory address to each  I/O device in the computer system is called:
a)    memory mapped I/O      b)Ported I/O
c)dedicated I/O                      d)Wired I/O
16.The ............ is defined as the time the output is active divided by the total period of the output signal.
a)On time   b)Off time    c)Duty cycle   d)Active ratio
20.when transistors are used in digital circuits the usually operate in the:
a)active region                       b)breakdown region
c)saturation and cutoff region   d)Linear region
22.The dc current through each diode in a bridge rectifier equals:
a)the load current              b)half the dc load current
c)twice the dc load             d)one fourth the dc load

24.. If the voltage on the base of a transistor increases, does it:
a)Turn On  b)Turn Off   c)Not enough information
d)Remain the same

26:  A resistor and capacitor in series is called a:
http://www.talkingelectronics.com/images/50-Q's/50-Qs-22.gifhttp://www.talkingelectronics.com/images/50-Q's/50-Qs-38.gifa)Pulse circuit
b)Timing/Delay circuit
c)Oscillator Circuit/Frequency Circuit
d)Schmitt Circuit


28.  Technician A says that LED-1 will be ON and LED-2 will be OFF when the circuit is connected as shown below. Technician B says that both LED-1 and LED-2 will be ON when the circuit is connected as shown below. Who is correct? :
http://www.hwscience.com/physics/electronics/multiplechoice/diode2.jpg

a)technician A only.                              b)technician B only
.

c)neither Tech A nor Tech B.      d) Technician A nor Technician B
29. In an intrinsic semiconductor, the Fermi-level is
(A) closer to the valence band         (B) midway between conduction and valence band
(C) closer to the conduction band     (D) within the valence band

30. The dual of the Boolean expression: x + y + z is
(A) x .y + z    (B) x + yz    (C) x . y . z    (D) x.y.z

31. The type of power amplifier which exhibits crossover distortion in its output is
(A) Class A   (B) Class B    (C) Class AB   (D) Class C

33. Zener diodes are most commonly used in:
A. voltage amplifier circuits.            B. oscillator circuits.
C. power supply circuits.                 D. current limiting circuits

34.A resistor with colour bands Red, Violet, Green and Black will have a value
 (A)27 K±10%K  (B)2.7 M±20% K  (C)270 K±5% K    (D)2.7 K±2%K

35.The following data refers to an experiment carried out on a Zener diode:
Reverse voltage
Reverse current
1 V
1 µA
2 V
2 µA
3 V
10 µA
4 V
20 µA
The Zener voltage will be between:
(a)   1 V and 2 V  (b) 2 V and 3 V  (c) 3 V and 4 V  (d)none of these

39. What is the approximate characteristic voltage that develops
    across a red LED?
a)1.7 V       b)3.4V       c)0.6V         d)5V

40.  The resistor marked  is: 
http://www.talkingelectronics.com/images/50-Q's/50-Qs-21.gif
Base Bias Resistor
Load Resistor
Emitter Feedback Resistor
Bypass Resistor

42. Name the 4 components: 
http://www.talkingelectronics.com/images/50-Q's/50-Qs-24.gif










Photo darlington transistor, switch, capacitor, coil
Transistor, mercury switch, piezo, coil
Photo transistor, reed switch, piezo, coil
Photo darlington transistor, reed switch, piezo, coil
47: A minterm of the Boolean-function, f(x, y, x) is
(A x¢ + y + z       (B) x y z¢    (C) x z    (D) (y +z) x

48.Space charge region around a p-n junction
(A) does not contain mobile carriers
(B) contains both free electrons and holes
(C) contains one type of mobile carriers depending on the level of doping of the p or   n   regions
(D) contains electrons only as free carriers


50. The gate that assumes the 1 state, if and only if the input does not take a 1 state is   called________.
(A) AND gate                    (B) NOT gate 
 (C) NOR gate                   (D) Both (B) & (C)


                                       
Answer:
1-d,        2-b           3-a  4-c   5-c  6-a  7-b  8-b  9-d  10-b  11-c  12-d   13-c  14-a  15-c  16-c  17-a
18-b  19-b  20-c  21-d  22-a  23-a  24-c  25-c  26-b  27-b  28-a  29-c  30-c  31-b  32-c  33-c  34-b
35-b  36-b37-c 38-d 39-a 40-a 41-b 42-d  43-a 44-a 45-b 46-a 47-b  48-a  49-c       50-d


for exciting mini project http://electrofb.blogspot.in/2014/02/70w-inverter.html
  

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