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Question #661Radio Theory and Communication Principles

SSB stands for

  1. Single Sideband ✓ Correct answer
  2. Double Sideband
  3. Suppressed Sideband only
  4. Simple Sideband
Explanation: SSB means Single Sideband.

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Question #662Radio Theory and Communication Principles

The intermediate frequency (IF) in many AM broadcast receivers is

  1. 455 kHz ✓ Correct answer
  2. 10.7 MHz
  3. 1 MHz
  4. 455 MHz
Explanation: A common AM broadcast IF is 455 kHz.

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Question #663Radio Theory and Communication Principles

A common IF used in FM broadcast receivers is

  1. 10.7 MHz ✓ Correct answer
  2. 455 kHz
  3. 1 MHz
  4. 455 MHz
Explanation: A common FM broadcast IF is 10.7 MHz.

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Question #664Radio Theory and Communication Principles

SWR stands for

  1. Standing Wave Ratio ✓ Correct answer
  2. Signal Wave Ratio
  3. Simple Wave Reading
  4. Series Wave Resistance
Explanation: SWR is Standing Wave Ratio.

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Question #665Radio Theory and Communication Principles

An SWR of 1:1 indicates

  1. Perfect match ✓ Correct answer
  2. Severe mismatch
  3. Open circuit only
  4. Short circuit only
Explanation: 1:1 SWR means the load matches the line impedance.

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Question #666Radio Theory and Communication Principles

A dummy load is used to

  1. Test a transmitter without radiating ✓ Correct answer
  2. Increase antenna gain
  3. Receive weak signals
  4. Measure frequency only
Explanation: A dummy load absorbs RF power for testing without radiation.

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Question #667Antennas and Radio Wave Propagation

A Yagi antenna is a type of

  1. Directional antenna ✓ Correct answer
  2. Omnidirectional antenna
  3. Isotropic antenna
  4. Dummy load
Explanation: A Yagi-Uda antenna is directional.

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Question #668Antennas and Radio Wave Propagation

An isotropic antenna is an

  1. Ideal point-source radiator used as a reference ✓ Correct answer
  2. Practical mobile whip
  3. Type of dummy load
  4. FM only antenna
Explanation: Isotropic radiator is a theoretical reference antenna.

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Question #669Antennas and Radio Wave Propagation

Ground wave propagation is most useful at

  1. MF and lower HF ✓ Correct answer
  2. Microwave only
  3. Optical frequencies
  4. VLF only never HF
Explanation: Ground-wave coverage is important on MF and lower HF.

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Question #670Antennas and Radio Wave Propagation

Skip distance is related to

  1. Sky-wave propagation ✓ Correct answer
  2. Optical fibre
  3. Waveguide only
  4. DC circuits
Explanation: Skip distance is a sky-wave propagation concept.

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Question #671Antennas and Radio Wave Propagation

The ionospheric layer most responsible for long-distance HF at night is often the

  1. F layer ✓ Correct answer
  2. D layer
  3. C layer
  4. G layer
Explanation: The F region supports much nighttime long-distance HF.

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Question #672Radio Theory and Communication Principles

CW in amateur radio usually means

  1. Continuous Wave (Morse) ✓ Correct answer
  2. Carrier Width
  3. Coded Width
  4. Circuit Watt
Explanation: CW commonly refers to Morse code / continuous-wave telegraphy.

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Question #673Radio Theory and Communication Principles

The bandwidth of an SSB voice signal is typically about

  1. 2.4 to 3 kHz ✓ Correct answer
  2. 15 kHz
  3. 150 kHz
  4. 1 Hz
Explanation: SSB voice channels are typically a few kilohertz wide.

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Question #674Radio Equipment, Measurements and Safety

RF safety is important because

  1. RF energy can cause heating of body tissue ✓ Correct answer
  2. RF is always visible
  3. RF cannot be measured
  4. RF has no biological effect
Explanation: Sufficient RF exposure can heat body tissue; safe practices are required.

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Question #675Radio Equipment, Measurements and Safety

Before working on a transmitter you should

  1. Switch off and discharge high-voltage circuits ✓ Correct answer
  2. Increase power to maximum
  3. Disconnect only the microphone
  4. Hold the antenna
Explanation: Safety first: power down and discharge dangerous voltages.

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Question #676Radio Equipment, Measurements and Safety

A multimeter can typically measure

  1. Voltage, current and resistance ✓ Correct answer
  2. Only frequency
  3. Only SWR
  4. Only RF power
Explanation: A standard multimeter measures V, I and R.

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Question #677Amateur Radio Regulations and Licensing

The Indian administration that regulates amateur radio is under

  1. Ministry of Communications / WPC wing ✓ Correct answer
  2. Ministry of Defence only
  3. Ministry of Tourism
  4. State police only
Explanation: Amateur radio licensing in India is under the central communications administration (WPC).

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Question #678Amateur Radio Regulations and Licensing

ASOC stands for

  1. Amateur Station Operator’s Certificate ✓ Correct answer
  2. Amateur Satellite Operating Club
  3. Automatic Station Operating Code
  4. Advanced Signal Operator Course
Explanation: ASOC is Amateur Station Operator’s Certificate.

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Question #679Amateur Radio Regulations and Licensing

Amateur radio may not be used for

  1. Commercial business communication ✓ Correct answer
  2. Technical experimentation
  3. Emergency communication
  4. Training in radio technique
Explanation: Business/commercial traffic is not permitted in the amateur service.

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Question #680Amateur Radio Regulations and Licensing

A station log should include at least

  1. Date, time, frequency/band and stations worked ✓ Correct answer
  2. Only your name
  3. Only antenna type
  4. Only power supply voltage
Explanation: Logs record when, where (frequency) and with whom you communicated.

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