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Question #1Radio Theory and Communication Principles

Parameter that determines lowest signal reception capability of a receiver is

  1. Sensitivity ✓ Correct answer
  2. Fidelity
  3. Selectivity
  4. Squelch
Explanation: Sensitivity is the ability to receive weak signals.

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Question #2Radio Theory and Communication Principles

TRF stands for

  1. Turning radio frequency
  2. Turning rod frequency
  3. Tuned radio feed
  4. Tuned radio frequency ✓ Correct answer
Explanation: TRF means Tuned Radio Frequency.

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Question #3Radio Theory and Communication Principles

If a super hetero dyne radio receiver is tuned to 1255 KHz & the IF frequency is 455KHz, then the frequency of the local oscillator of the receiver is

  1. 1255 KHz
  2. 800 KHz
  3. 1710 KHz ✓ Correct answer
  4. 455 KHz
Explanation: For a conventional high-side oscillator, LO = 1255 + 455 = 1710 kHz.

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Question #4Basic Electricity and Electronics

Kirchhoff’s voltage Law states that

  1. The sum of voltages in a loop is zero
  2. The algebraic sum of voltages in a loop is zero ✓ Correct answer
  3. The sum of currents at a junction is zero
  4. The algebraic sum of currents at a junction is zero

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Question #5Radio Theory and Communication Principles

Among all these materials, which one has poor conductivity ?

  1. Copper
  2. Aluminum
  3. Silicon ✓ Correct answer
  4. Silver
Explanation: Silicon is a semiconductor and conducts much less readily than the listed metals.

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Question #6Radio Theory and Communication Principles

A magnet does not attract which one in the following

  1. Nickel
  2. Aluminum ✓ Correct answer
  3. Iron
  4. Cobalt
Explanation: Aluminium is not ferromagnetic; nickel, iron and cobalt are attracted by a magnet.

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Question #7Basic Electricity and Electronics

The unit of resistance is

  1. Mho
  2. Volts
  3. Ampere
  4. Ohm ✓ Correct answer
Explanation: The SI unit of resistance is the ohm.

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Question #8Radio Theory and Communication Principles

The expanded form for ‘LDR’ is

  1. Light Emitting Display
  2. Low Dependent Reading
  3. Light Emitting Diode
  4. Light Dependent Resistor ✓ Correct answer
Explanation: LDR means Light Dependent Resistor.

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Question #9Basic Electricity and Electronics

The three leads of a common transistor are

  1. Base Collector Case
  2. Emitter Collector Bias
  3. Collector Base Omitter
  4. Collector Base Emitter ✓ Correct answer
Explanation: A bipolar transistor has collector, base and emitter terminals.

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Question #10Basic Electricity and Electronics

If R is resistance, I is current and V is voltage, then Ohms law states that

  1. R=V/I ✓ Correct answer
  2. I=R/V
  3. V=R/I
  4. V/(R/I)=1
Explanation: Ohm’s law gives R = V/I.

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Question #11Basic Electricity and Electronics

If two capacitors are placed in series, is the final capacitance will be:

  1. Higher than the sum of the two capacitors
  2. Lower than the least of the two capacitors ✓ Correct answer
  3. The sum of the two capacitors
  4. Cannot be determined the given data.
Explanation: Series capacitance is less than the smallest individual capacitor.

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Question #12Basic Electricity and Electronics

Which is the unit of energy in electronics?

  1. Ohm
  2. Ampere
  3. Joules ✓ Correct answer
  4. Watt
Explanation: Energy is measured in joules.

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Question #13Radio Theory and Communication Principles

The high frequency band (HF) is

  1. 3KHz to 30KHz
  2. 3MHz to 30MHz ✓ Correct answer
  3. 30KHz to 300KHz
  4. 30MHz to300MHz
Explanation: The HF band extends from 3 MHz to 30 MHz.

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Question #14Antennas and Radio Wave Propagation

Among the following which is not a directional antenna

  1. Whip antenna ✓ Correct answer
  2. Yagi-Uda antenna
  3. Loop antenna
  4. Dish antenna
Explanation: A whip antenna is generally omnidirectional in the horizontal plane.

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Question #15Basic Electricity and Electronics

The unit of current is

  1. Volts
  2. Ampere ✓ Correct answer
  3. Watt
  4. Hertz
Explanation: The SI unit of current is the ampere.

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Question #16Radio Theory and Communication Principles

If a small value of inductance is connected in parallel with a large value, the combined inductance will be

  1. The same
  2. Higher
  3. Lower ✓ Correct answer
  4. Cannot be determined with the given data.
Explanation: For inductors in parallel, the equivalent inductance is lower than the smaller inductance (for ideal uncoupled inductors).

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Question #17Basic Electricity and Electronics

The equivalent capacitance when three capacitors of 150 micro farad are connected in series is

  1. 450 micro farad capacitor
  2. 300 micro farad capacitor
  3. 150 micro farad capacitor
  4. 50 micro farad capacitor ✓ Correct answer
Explanation: Three equal 150 µF capacitors in series give 150/3 = 50 µF.

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Question #18Basic Electricity and Electronics

A resistor with color bands: Red-Violet-Orange-Silver, has the value of

  1. 23 kilo Ohm , 5% tolerance
  2. 27 kilo Ohm , 5% tolerance
  3. 2.7 kilo Ohm , l0%tolerance
  4. 27 kilo Ohm , 10% tolerance ✓ Correct answer
Explanation: Red-violet-orange gives 27 kΩ; silver indicates ±10% tolerance.

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Question #19Basic Electricity and Electronics

The abbreviation of RMS voltage is

  1. Railway Mail Service voltage
  2. Real Mean Square voltage
  3. Root Mean Square voltage ✓ Correct answer
  4. Root Mean Service voltage
Explanation: RMS means Root Mean Square.

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Question #20Basic Electricity and Electronics

If the peak voltage of a sinusoidal ac supply is 150 volts, the RMS value is

  1. Less than peak value ✓ Correct answer
  2. More than peak value
  3. Equal to peak value
  4. Not related to peak value of the voltage
Explanation: For a sine wave, RMS voltage is 0.707 times peak voltage.

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