Practice MCQ

Q1: A half-wave antenna is often called

A. bi polar
B. yagi
C. dipole
D. beam

Q2: The correct colour coding for the earth wire in a flexible mains lead is

A. blue
B. red
C. black
D. green

Q3: Two basic types of bipolar transistors are

A. diode and triode types
B. p-channel and n-channel types
C. NPN and PNP types
D. Varicap and Zener types

Q4: A common use for a permanent magnet is

A. A computer speaker
B. An optical mouse
C. A keyboard
D. A magnetic loop antenna

Q5: Transformer works on the principle of

A. Self inductance
B. Mutual inductance
C. Both
D. None

Q6: Capacitor is a

A. Passive device
B. Active device
C. Both
D. None

Q7: Resistance of insulator is

A. Zero
B. Very high
C. Low
D. None

Q8: Conductance is proportional to

A. Resistance
B. Inverse of resistance
C. Reactance
D. None

Q9: Power formula is

A. P=VI
B. V=IR
C. P=IR
D. None

Q10: Kirchhoff's law states

A. Sum of currents zero
B. Node voltage zero
C. Sum of voltage drops equals supply
D. None

Q11: Law of electromagnetism is

A. Newton's law
B. Faraday's law
C. Kirchhoff's law
D. Kepler's law

Q12: Bridge rectifier is

A. Full wave
B. Half wave
C. Both
D. None

Q13: Diode used as

A. Rectifier
B. Detector
C. Switch
D. All

Q14: Oscillator works on

A. Positive feedback
B. Negative feedback
C. No feedback
D. None

Q15: Common Emitter amplifier output phase is

A. 45°
B. 90°
C. 180°
D. 270°

Q16: Modulation frequency relation is

A. Signal > Carrier
B. Signal < Carrier
C. Direct
D. Equal

Q17: Typical IF value is

A. 450 KHz
B. 455 KHz
C. 500 KHz
D. 405 KHz

Q18: Detector output frequency

A. Audio
B. RF
C. IF
D. None

Q19: Receiver sensitivity governed by

A. RF
B. Detector
C. AF
D. None

Q20: Noise is expressed as

A. S/N ratio
B. N/S ratio
C. Level
D. None

Q21: Most stable oscillator is

A. RC
B. Hartley
C. Colpitts
D. Crystal

Q22: 7100KHz propagation is

A. Tropospheric
B. Ionospheric
C. Ground wave
D. Space wave

Q23: Dipole length at 300MHz should be

A. 10m
B. 1m
C. 0.1m
D. 1cm

Q24: Best VHF antenna is

A. Dipole
B. Log periodic
C. Yagi
D. None

Q25: A1A transmission is

A. AM
B. FM
C. Both
D. None

Q26: Skip distance is between

A. Transmitter and receiver
B. Trasmitter and Ionosphere
C. Receiver and Ionosphere
D. layers

Q27: TV sideband system is

A. ISB
B. VSB
C. SSB
D. All

Q28: BJT microwave limitation depends on

A. Size
B. Transit time
C. Power
D. All

Q29: HF day reflection layer is

A. F2
B. F1
C. E
D. D

Q30: The colour bands of 4.7k.ohms 5% resistor are

A. yellow violet orange and gold
B. yellow violet red and gold
C. yellow violet orange and silver
D. yellow violet red and silver

Q31: The doping concentrations of Emitter- Base and Collector in a NPN transistor is

A. heavy moderate and light
B. heavy light and moderate
C. moderate light and heavy
D. moderate heavy and light

Q32: For a step down transformer;the relation between the number of turn in primary (Np) and the number of turns in secondary (Ns) is

A. Ns>Np
B. Ns<Np
C. Ns=Np
D. none of the above

Q33: The power conversion efficiency of a full wave rectifier is

A. 40.60%
B. 81.20%
C. 100%
D. zero

Q34: The length of dipole; reflector; and director of a Yagi antenna in term of wave length are

A. 0.55 λ 0.5λ and 0.45λ
B. 0.45 λ 0.5λ and 0.55 λ
C. 0.5 λ 0.55 λ and 0.45λ
D. 0.55λ 0.45λ and 0. 5 λ

Q35: The circuit that enables the radio receiver output to remainscut off when carrier is absent is

A. AGC
B. squelch
C. delayed AGC
D. noise limiter

Q36: The category of Pulse Modulation that comes under digital system is

A. Pulse code modulation
B. Pulse amplitude modulation
C. Pulse time modulation
D. All the above

Q37: The device that can be used as a voltage regulator is

A. Gun diode
B. Zener diode
C. Pin diode
D. both a&b

Q38: The most suitable antenna for VHF transmission is

A. dipole
B. log periodic
C. Yagi
D. none of the above

Q39: What is A1A transmission

A. amplitude of the carrier is modulated
B. frequency of the carrier is modulated
C. both a & b
D. none of the above

Q40: The skip distance is the distance between is

A. transmitter and receiver
B. transmitter and ionospheric layer
C. receiver and ionospheric layer
D. between two ionospheric layers

Q41: The side band system adopted for television transmission is

A. independent side band
B. vestigial side band
C. suppressed side band
D. all the above

Q42: One of the limitations of usage of BJT at micro wave frequencies is

A. size
B. transit time
C. power
D. all the above

Q43: The layer that reflects higher end frequencies in HF range during the day time is

A. F2 layer
B. F1 layer
C. E layer
D. D layer

Q44: The reactance of a capacitor increases when the frequency is

A. increased
B. decreased
C. zero
D. remains constant

Q45: The elements in the tank circuit of a Colpitts oscillator are

A. L and C
B. R and C
C. R and L
D. R L and C

Q46: The circuit that reduces ripples from the output of a rectifier is

A. Limiter
B. Discriminator
C. Blanker
D. Filter

Q47: Express the gain of an amplifier in dBm when output power of it is 100mW

A. 10dBm
B. 20 dBm
C. 40 dBm
D. 0 dBm

Q48: The output of an amplifier with 10 dB gain and input of 1mW is

A. 10mW
B. 100mW
C. 1mW
D. 0 mW

Q49: The transformers are rated in

A. Watts
B. Volts
C. Amperes
D. volt-amperes

Q50: Batteries are connected in parallel to get more

A. Current capacity
B. Voltage capacity
C. both a&b
D. none of the above

Q51: A super heterodyne receiver with local oscillator frequency range 3.455 to 30.455MHzis capable of receiving the input signal range is

A. 88-108MHz
B. 3-30 MHz
C. 565-1600MHz
D. 2-17Mhz

Q52: The capability of a receiver to receive weakest possible signal is its

A. Selectivity
B. Sensitivity
C. Fidelity
D. all of the above

Q53: The bridge rectifier is

A. Fullwave type
B. half wave type
C. both a&b
D. none of the above

Q54: What are the effects of moving a closed wire loop through a magnetic field?

A. A voltage is induced in the wire
B. A current is induced in the wire
C. The polarity across the wire depends on the direction of motion
D. All the above

Q55: What do you call the characteristic of a magnetic material whereby a change in magnetization lags the application of a magnetizing force?

A. Hysteresis
B. Induction
C. Retentivity
D. Reluctance

Q56: Mutual induction is dependent on

A. winding ratios
B. output polarities
C. DC voltage levels
D. current changes

Q57: What is the name for the distance a radio wave travels during one complete cycle

A. Wave speed
B. Waveform
C. Wavelength
D. Wave spread

Q58: What device increases the low-power output from a hand-held transceiver

A. A voltage divider
B. An RF power amplifier
C. An impedance network
D. A voltage regulator

Q59: What is the name of a device that combines several semiconductors and other components into one package?

A. Transducer
B. Multi-pole relay
C. Integrated circuit
D. Transformer

Q60: Which of these components is made of three layers of semiconductor material?

A. Alternator
B. Bipolar junction transistor
C. Triode
D. Pentagrid converter

Q61: What is the voltage across a 10-ohm resistor if a current of 1 ampere flows through it?

A. 10 volts
B. 1 volt
C. 11 volts
D. 9 volts

Q62: What is the purpose of the squelch control on a transceiver?

A. To set the highest level of volume desired
B. To set the transmitter power level
C. To adjust the automatic gain control
D. To mute receiver output noise when no signal is being received

Q63: What circuit is used to process signals from the RF amplifier and local oscillator and send the result to the IF filter in a super-heterodyne receiver?

A. Balanced modulator
B. IF amplifier
C. Mixer
D. Detector

Q64: What type of bias is required for an LED to emit light?

A. Reverse bias
B. Forward bias
C. Zero bias
D. none of the above

Q65: How fast does a radio wave travel through free space?

A. at the speed of light
B. At the speed of sound
C. Its speed is inversely proportional to its wavelength
D. Its speed increases as the frequency increases

Q66: How does the wavelength related to frequency?

A. Wavelength and frequency are inversely proportional
B. The wavelength gets longer as the frequency increases
C. here is no relationship between wavelength and frequency
D. The wavelength depends on the bandwidth of the signal

Q67: How many milliamperes is 1.5 amperes?

A. 15 milliamperes
B. 150 milliamperes
C. 1500 milliamperes
D. 15,000 milliamperes

Q68: What is the primary advantage of single sideband over FM

A. SSB signals are less susceptible to interference
B. SSB signals are easier to tune
C. SSB signals have narrower bandwidth
D. All the above options are correct

Q69: A coaxial feed-line is constructed from

A. a single conductor
B. two parallel conductors separated by spacers
C. braid and insulation around a central conductor
D. braid and insulation twisted together

Q70: Which of the following types of emission has the narrowest bandwidth?

A. FM voice
B. SSB voice
C. CW
D. Slow-scan TV

Q71: Which of the following electronic components can amplify signals?

A. Transistor
B. Variable resistor
C. Electrolytic capacitor
D. Diode

Q72: Best VHF antenna

A. Dipole
B. Log periodic
C. Yagi
D. none of the above

Q73: What are the names of the two electrodes of a diode?

A. Plus and minus
B. Source and drain
C. anode and cathode
D. Base and emitter

Q74: How much power is being applied in a circuit when the applied voltage is 13.8 volts DC and current is 10A

A. 138 Watts
B. 0.7 Watts
C. 1.38watts
D. 3.8watts

Question Pool: General Grade

SECTION: A: Radio Theory

Model question pool - 2