Digital modulation techniques are
Explanation: Phase-shift keying (PSK) is a digital modulation technique.
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The following idle component dissipates energy
Explanation: A resistor dissipates electrical energy as heat; ideal capacitors and inductors do not dissipate average real power.
The most common stage used for amplifying an electrical signal is
Explanation: The common-emitter configuration is widely used for voltage amplification.
The biasing of a transistor is to
Explanation: Proper transistor biasing establishes a stable operating point and helps prevent thermal runaway.
The ideal value of ripple factor should be
Explanation: An ideal rectifier output has zero ripple; hence the ideal ripple factor is zero.
A centre-tapped full-wave rectifier employs
Explanation: A centre-tapped full-wave rectifier uses two diodes. A bridge full-wave rectifier uses four.
The following is used as a Voltage smoothing device
Explanation: A capacitor is commonly used to smooth rectified DC.
The following modulation is used for audio transmission in TV broadcast
Explanation: FM is used for television sound broadcasting in the conventional analogue system.
NICAM technique is used in TV broadcast
Explanation: NICAM is a digital system used to transmit stereo (and sometimes dual-language) television audio.
Conventional Facsimile machine sends ______ data over _____ media
Explanation: Conventional fax machines transmit analogue information over a telephone line.
Under Indian Wireless Telegraph rules, 1973, the minimum age to work on a radio transmitting apparatus is ______ years
Explanation: For current ASOC eligibility under the Telecommunications (Amateur Services) Rules, 2024, the minimum age is 12 years (option A). The question stem cites the 1973 rules; older materials often used 18, but this bank is aligned to current ASOC practice.
An amateur is forbidden to transmit
Explanation: Amateur service must not be used for business, entertainment/music broadcasts or advertisements.
Log containing chronological record of all transmissions should be preserved for
Explanation: The 2024 rules require logs to be preserved for one year from the date of the last entry; 12 months is option D.
Log containing chronological record of all transmissions should contain
Explanation: The legacy question’s intended answer is “all of the above”; the current 2024 rules specify date/time, communication summary, tests, exchanged stations, emission and opening/closing details.
Which of the following should be given top priority?
Explanation: Distress traffic has priority over urgency, safety and routine traffic.
The following is not an amateur call sign of India
Explanation: VU44AB does not follow the normal Indian amateur call-sign format shown by the other choices.
The standard time & frequency signal in India is
Explanation: The Indian standard time and frequency broadcast is commonly associated with the 10 MHz transmission.
The standard time & frequency signal in India call sign is
Explanation: ATA is the call sign used for India’s standard time and frequency service.
The abbreviation for end of message in Morse code is
Explanation: AR is the Morse procedural signal meaning end of message/transmission.
QTR stands for ?
Explanation: QTR asks for the correct time.