Company: Bharat Sanchar Nigam Ltd

BSNL JTO Exam Question Paper Year 2008

The intrinsic impedance of free space-
a) is independent of frequency
b) decreases with increase of frequency
c) increases with increase of frequency
d) varies as square root of frequency
Answer is : a

A system consists of 12 poles and 2 zeroes. Its high frequency asymptote in its magnitude plot has a slope of –
a) –200 dB/decade
b) –240 dB/decade
c) –230 dB/decade
d) –320 dB/decade
Answer: a

Considering the conditions-
1. High loop gain
2. Less ringing
3. Greater damping
4 Negative dB gain margin
System stability requirements would include?
a) 1 and 3 b) 1, 2 and 3 c) 1 and 4 d) 2, 3 and 4
Answer: d

In the equatorial plane only Geosynchronous satellite are launched because it is the only plane which provides –
a) 24 hour orbit
b) stationary satellite
c) global communication
d) zero-gravity environs
Answer: b

Radio Broadcasting is an example of –
a) space multiplexing
b) time multiplexing
c) frequency multiplexing
d) none of the above
Answer: c

PAM signals can be demodulation by using a –
a) Low pass filters (LPE) alone
b) A Schmitt trigger followed by a LPF
c) A differentiator followed by a LPF
d) A clipper circuit by a LPF
Answer: b

In an FDM receiver channels can be separated by using –
a) AND gates
b) Band pass
c) differentiation
d) Integration
Answer: a

The most common modulation system used for telegraphy is-
a) frequency shift keying
b) two – tone modulation
c) pulse code modulation
d) single tone modulation
Answer: a

Use of varoctor diode in generation of modulated segial be-
a) FM generation only
b) 100AM generation only
c) PM generation only
d) both PM and AM generation
Answer: a

In colour picture tube shadow mask is used to-
a) reduce x-ray emission
b) ensure that each beam strikes only its own dots
c) increase screen brightness
d) provide degaussing for the screen
Answer: c

The circuit that separates composite video warefore from the sync pulses is-
a) the keyed AGC amplifar
b) a clipper
c) an integrator
d) a sawtooth current
Answer: d

Band width of microwaves is-
a) 1GHz -103 GHz
b) 1GHz –100 GHz
c) 1 GHz –10 GHz
d) 1 GHz – 106 GHz
Answer: b

In transverse Magnetic mode-
a) no electric line is in direction of propagation
b) no magnetic line is in direction of propagation
c) bath magnetic & electric lines are is direction of propagation
d) neither magnetic nor electric lines in direction of propagation
Answer: b

Signal transmission in sky wave propagation is due to –
a) Reforction of wave
b) Reflection of wave
c) Pierus through Inosphere
d) None
Answer: a

According to Barkhausen Criterion Phase shift of signal should be –
a) 6000
b) 9000
c) 18000
d) 36000
Answer: d

The transmission does not have –
a) Partition noise
b) Flicker noise
c) resistance
d) Short noise
Answer: a

Varoctor diode has non linearity of –
a) capacitance
b) Inductance
c) Resistance
d) Is a linear device
Answer: a