Have a Look , Friend Here I am Providing Previous year Airport Authority of India Junior Executive Question Paper :


1. In a communication system, noise is most likely to affect the signal
(a) at the destination (b) In the channel
(c) in the information source (d) at the transmitter

2. Indicate the false statement. Fourier analysis shows that the saw tooth
wave consist of
(a) fundamental and subharmonic sine waves (b) a fundamental sine wave and an infinite
number of harmonics
(c) fundamental and harmonic sine waves whose amplitude decreases with
the harmonic number (d) sinusoidal voltages, some of which are small
enough to ignore in
practice

3. One of the following types of noise becomes a great importance at high
frequencies. Is the
(a) random noise (b) shot noise
(c) impulse noise (d) transit-time noise

4.Indicate the false statement. The square of the thermal noise voltage
generated by a resistor is proportional to
(a) its temperature (b) Its resistance
(c) Boltzmann’s Constant (d) the bandwidth over which it is measured

5.If the plate supply voltage for a plate modulated class C amplifier is V, the
maximum plate-cathode voltage could be almost as high as
(a)4v (b)3v
(c)2v (d)1v
6. Which one will be stable if characteristics equation is
(a) AS^2+BS+C (b) AS^2-BS-C
(c) AS^4+BS^2+CS+D (d) -AS^2+BS-C

7. When microwave follows curvature of the earth, this I know as
(a) fading (b) Ducting
(c) troposphere scatter (d) ionosphere reflection

8. Broadband long distance communications are originally made possible by
the advent of
(a) telegraph cables (b) repeater amplifiers
(c) HF radio (d) Geostationary satellites

9. Switching systems
(a) Improve the efficiency of data transfer (b) are not used in data system
(c) require additional lines (d) are limited to small data networks

10. Basic group B
(a) occupies the frequency range from 60 to 108 k hz (b) consist of erect channels only
(c) is formed at the group translating equipment (d) consist of five super group

11. In differential amplifiers, the common emitter current is made constant
(a) To make Ad (differential gain) very small (b) To make Ac (common mode gain) very small
(c) To make the amplifier symmetrical (d) To keep CMRR constant

12. Given BCD number 1001 0011, its decimal equivalent is
(a) 147 (b) 143
(c) 93 (d) 39

13. An amplifier has voltage gain of 50. This gain in db will be
(a) 17 db (b) 31 db
(c) 34 db (d) 68 db

14. In a E plane Tee, the output of the two rams are
(a) 180 degree out of phase (b) In the same phase
(c) 90 degree out of phase (d) none of these
15. waveguide are generally made of
(a) Aluminum (b) Bronze
(c) Both (a) and (b) (d) none of these

Just as a voltage amplifier signal voltage a power amplifier.
amplifier power
2.amplifier signal
3.converts the signal ac power into DC power
4.converts a dc power into useful AC power

Cross over distortion in class - B push-p amplifiers:
1. Is due to transistor operating near saturation region
2. Can be eliminated by operating them in class operation
3. Occurs because two power transistors do not exactly matching parameters
4. Always occurs in low signal area

If the load p.f. is 0.866, then the average p.f. the v-bank is
1. 0.886
2. 0.75
3.0.51
4. 0.65

AT-T connection has higher ratio of utilizax that n a V - V connection
only when
1. Identical transformers are used
2. Load power factor is leading
3. Load power factor is unity
4. Non-identical transformers are used

A commercial power supply has a voltage regulation of:
1. 1%
2.5%
3.20%
4.50%

Which stage is of a d.c. power supply uses zener diode
1. Rectifier
2. Voltage divider
3. Filter
4. Regulator

Which rectifier requires 4 diodes ?
1. half wave rectifier
2. full wave rectifier
3. bridge type rectifier
4. Voltage quadrupler

The advantage of dynamic RAMs over static RAMs is
1. Lower power consumption
2. Higher power consumption
3. Higher packing density
4. Lower packing density


The address range for M = 64 words storage in hexadecimal format is
1. 00 to 3F
2. 00 to FF
3. 0 to 3
4. 0 to F

The 8085 is a – microprocessor
1. 4 bit
2. 8 bit
3. 16 bit
4. 32 bit

The voltage gain of a common base amplifier depends on
1. Load resistor RL
2. input resistance of transistor
3. Ac alpha
4. All the above

A JFET has the disadvantage of
1. Having low input impedance
2. Having high output impedance
3. Having small gain band-width product
4. Possessing positive temperature coefficient

A FET is preferred over an ordinary transistor because it
1. Permits high degree of isolation between input & output circuits
2. Has low noise level
3. Has very high power gain
4. Has all the above properties

To turn a UJT ON, the forward bias on emitter diode should be:
1. more than the peak point voltage
2. less than the peak point voltage
3. Equal to the peak point voltage
4. Equal to the stand - off voltage

Which of the following statements is wrong for transistor biasing
methods:
1. The base resistor method does not provide stabilization of operating point
2. The biasing with feedback resistor provides only some stabilization
3. Base resistor method provides better stabilization than collector feedback
method
4.Voltage divider bias is widely used because it has stable operating point