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Question #381Basic Electricity and Electronics

Ohm's law describes the mathematical relationship between

  1. ohms, kilohm's, and megohms
  2. resistor size and resistor value
  3. resistance, voltage, and current ✓ Correct answer
  4. none of the above

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Question #382Radio Theory and Communication Principles

What are the effects of moving a closed wire loop through a magnetic field?

  1. A voltage is induced in the wire.
  2. A current is induced in the wire.
  3. The polarity across the wire depends on the direction of motion.
  4. All the above ✓ Correct answer

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Question #383Radio Theory and Communication Principles

What do you call the characteristic of a magnetic material whereby a change in magnetization lags the application of a magnetizing force?

  1. Hysteresis ✓ Correct answer
  2. Induction
  3. Retentivity
  4. Reluctance

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Question #384Basic Electricity and Electronics

Increasing the number of turns of wire on the secondary of a transformer will

  1. increase the secondary current
  2. decrease the secondary current ✓ Correct answer
  3. have no effect on the secondary current
  4. increase the primary current 103.Mutual induction is dependent on

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Question #385Basic Electricity and Electronics

Which of these components is made of three layers of semiconductor material?

  1. Alternator
  2. Bipolar junction transistor ✓ Correct answer
  3. Triode
  4. Pentagrid converter 108.What electrical component is usually composed of a coil of wire?

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Question #386Antennas and Radio Wave Propagation

The wavelength for a frequency of 25 MHz is:

  1. 15 m
  2. 32 m
  3. 4 m
  4. 12 m ✓ Correct answer
Explanation: The wavelength is λ = c/f ≈ 300/25 = 12 metres. The option text was cleaned of OCR spillover.

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Question #387Basic Electricity and Electronics

The reactance of an inductor increases as the:

  1. frequency increase ✓ Correct answer
  2. frequency decreases
  3. applied voltage increases
  4. applied voltage decreases 160.How is an ammeter usually connected to a circuit?

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Question #388Basic Electricity and Electronics

In a transformer the energy is conveyed from primary to secondary

  1. through cooling coil
  2. through air
  3. by the flux ✓ Correct answer
  4. none of the above 164.A transformer core is laminated to

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Question #389Basic Electricity and Electronics

The degree of mechanical vibrations produced by the laminations of a transformer depends on

  1. tightness of clamping
  2. gauge of laminations
  3. size of laminations
  4. all the above ✓ Correct answer

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Question #390Basic Electricity and Electronics

The purpose of providing an iron core in a transformer is to

  1. provide support to windings
  2. reduce hysteresis loss
  3. decrease the reluctance of the magnetic path ✓ Correct answer
  4. reduce eddy current losses 167.A transformer cannot raise or lower the voltage of a D.C. supply because

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Question #391Basic Electricity and Electronics

Primary winding of a transformer

  1. is always a low voltage winding
  2. is always a high voltage winding
  3. could either be a low voltage or high voltage winding ✓ Correct answer
  4. none of the above 169.An ideal transformer is one which has

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Question #392Basic Electricity and Electronics

The transformer laminations are insulated from each other by

  1. mica strip
  2. thin coat of varnish ✓ Correct answer
  3. paper
  4. any of the above

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Question #393Basic Electricity and Electronics

The size of a transformer core will depend on

  1. frequency
  2. area of the core
  3. flux density of the core material
  4. All of the above ✓ Correct answer
Explanation: Transformer core size depends on frequency, core area and flux density of the core material (among other design factors).

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Question #394Basic Electricity and Electronics

The primary and secondary winding of a transformer are

  1. Conductively linked.
  2. Inductively linked.
  3. Electrically linked. ✓ Correct answer
  4. Mechanically linked. 174.What type of component is often used as an adjustable volume control?

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Question #395Radio Theory and Communication Principles

The Law behind electromagnetism is

  1. Newton's law
  2. Faraday's law ✓ Correct answer
  3. Kirchhoff’s law
  4. Kepler's law

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Question #396Basic Electricity and Electronics

Increasing the number of turns on an inductor will make its inductance:

  1. decrease
  2. increase ✓ Correct answer
  3. remain unchanged
  4. become resistive 182.Which of the following is commonly used as a visual indicator?

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Question #397Basic Electricity and Electronics

Zener Diodes are used for

  1. Rectification
  2. Detection
  3. Voltage regulation ✓ Correct answer
  4. Current Regulation

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Question #398Basic Electricity and Electronics

The impedance of a resonant circuit is

  1. Zero
  2. Equal to resistance ✓ Correct answer
  3. Unity
  4. Equal to reactance 200.A Diode can be used as

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Question #399Radio Theory and Communication Principles

The output signal of an CE amplifier will be

  1. 45 deg out of phase
  2. 90 deg out of phase
  3. 180 deg out of phase ✓ Correct answer
  4. None of the above

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Question #400Radio Theory and Communication Principles

"VOX" stands for:

  1. volume operated extension speaker
  2. voice operated transmit ✓ Correct answer
  3. variable oscillator transmitter
  4. voice operated expander

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