Multiple Choice Question (MCQ) of Electronics page-17
241. Which of the following statement is true?
242. If the DC current gain of a transistor is given, can it be decided how much input base current will be required to saturate the transistor?
243.The equation hƒe = hFe/(1-(ICBO+ IB ) ∂hFE/(∂IC )) is valid
a) The saturation voltage VCF of silicon transistor is more than germanium transistor.
b) The saturation voltage VCE for germanium transistor is more than silicon transistor.
c) The saturation voltage VCE for silicon transistor is same as that for germanium.
d) The saturation voltage VCE for silicon transistor is lower than germanium transistor.
244. The stability factor of transistor in action region is
a) In the saturation region of the transistor
b) In the cut-off region of the transistor
c) In the active region of the transistor
d) In any of the above regions of the transistor
245. The germanium transistors are seldom used above
a) Very small
b) Very high
c) Usually less than unity
d) Always greater than one
246. The power dissipation at the collector junction cause increase in collector current and subsequent increase in more power dissipation at the junction. This phenomenon is known as
a) 60°C temperature
b) 75°C temperature
c) 175°C temperature
d) 125°C temperature
247. The amplifiers invariably described based on the
a) Thermal gradient
b) Thermal instability
c) Thermal runaway
d) Thermal dissipation
e) Thermal coefficient
f) Thermal stability
248. In which of the following amplifier the output signal is zero for less than half a cycle if input signal voltage is sinusoidal?
a) Frequency range
b) Method of operation
c) Ultimate use
d) Type of load
e) All the above points
249. The application of a sinusoidal signal to the input of an ideal Class A amplifier will result in a sinusoidal output wave.
a) Class A
b) Class B
c) Class AB
d) Class C
250. In the high frequency region i.e., above midband, an amplifier state may behave like
251. If a 50 Hz square wave is applied to amplifier circuit and output is desired with less than 10% tilt, than lower 3 dB frequency must not exceed
a) Low-pass filter
b) High-pass filter
c) Current amplifier
d) Power amplifier
252. If the amplitude response is plotted on log-log paper for five stage amplifier, with will be the slop of plotted straight line?
a) 2 Hz
b) 1.6 Hz
c) 1.6 kHz
d) 1 Hz
253. The Johnson noise in amplifiers is
a) 30 dB per octave
b) 6 dB per octave
c) 100 dB per decade
d) (a) or (c)
e) 10 dB per decade
254. The noise for which the frequency spectrum is flat i.e., such a distribution which gives the same noise per unit bandwidth of the amplifier anywhere in frequency spectrum is called
a) Electrical noise
b) Thermal noise
c) Vibrational noise
d) Frequency noise
255. The noise in the amplifier which varies approximately as reciprocal to frequency at low frequencies is called
a) Blue noise
b) White noise
c) Red noise
d) Black noise
a) Shot noise
b) White noise
c) Flicker noise
d) Excess noise
Multiple Choice Question (MCQ) of Materials page-6:51. The permeability and permittivity of a medium are
A) independent of each other
B) related by the atomic number
C) related by the Boltzmann’s constant
D) related by the velocity of electromagnetic waves.
Multiple Choice Question (MCQ) of Materials page-5:41. Bakelite is
A) highly inflammable
B) low resistance conductor
C) a semi-conductor
Multiple Choice Question (MCQ) of Materials page-4:31. Which of the following pairs is commonly used in thermocouples?
D) Silver-German silver.