Electronics and Communication Engineering - Communication Systems

1.
A cordless telephone using separate frequencies for transmission in base and portable units is known as
duplex arrangement
half duplex arrangement
either (a) or (b)
neither (a) nor (b)
Answer: Option
Explanation:

Separate frequencies for transmission from base and portable units allows two way transmission and is called duplex arrangement.


2.
For attenuation of high frequencies we should use
shunt capacitance
series capacitance
inductance
resistance
Answer: Option
Explanation:

Since Xc for high frequencies is low, the high frequencies are shunted to ground and are not transmitted.


3.
A modem is classified as low speed if data rate handled is
upto 100 bps
upto 250 bps
upto 400 bps
upto 600 bps
Answer: Option
Explanation:

When data rate in bits per second is upto 600, modem is low speed.


4.
VSB modulation is preferred in TV because
it reduces the bandwidth requirement to half
it avoids phase distortion at low frequencies
it results in better reception
none of the above
Answer: Option
Explanation:

VSB (vestigial side band) transmission transmits one side band fully and the other side band partially thus, reducing the bandwidth requirement.


5.
A woofer should be fed from the input through a
low pass filter
high pass filter
band pass filter
band stop filter
Answer: Option
Explanation:

Woofer is a low frequency loud speaker covering the range 16 Hz to 500 Hz.